1 # SPDX-License-Identifier: GPL-2.0+
3 # (C) Copyright 2000 - 2013
4 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
9 This directory contains the source code for U-Boot, a boot loader for
10 Embedded boards based on PowerPC, ARM, MIPS and several other
11 processors, which can be installed in a boot ROM and used to
12 initialize and test the hardware or to download and run application
15 The development of U-Boot is closely related to Linux: some parts of
16 the source code originate in the Linux source tree, we have some
17 header files in common, and special provision has been made to
18 support booting of Linux images.
20 Some attention has been paid to make this software easily
21 configurable and extendable. For instance, all monitor commands are
22 implemented with the same call interface, so that it's very easy to
23 add new commands. Also, instead of permanently adding rarely used
24 code (for instance hardware test utilities) to the monitor, you can
25 load and run it dynamically.
31 In general, all boards for which a configuration option exists in the
32 Makefile have been tested to some extent and can be considered
33 "working". In fact, many of them are used in production systems.
35 In case of problems see the CHANGELOG file to find out who contributed
36 the specific port. In addition, there are various MAINTAINERS files
37 scattered throughout the U-Boot source identifying the people or
38 companies responsible for various boards and subsystems.
40 Note: As of August, 2010, there is no longer a CHANGELOG file in the
41 actual U-Boot source tree; however, it can be created dynamically
42 from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot, you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see https://lists.denx.de/pipermail/u-boot and
55 https://marc.info/?l=u-boot
57 Where to get source code:
58 =========================
60 The U-Boot source code is maintained in the Git repository at
61 https://source.denx.de/u-boot/u-boot.git ; you can browse it online at
62 https://source.denx.de/u-boot/u-boot
64 The "Tags" links on this page allow you to download tarballs of
65 any version you might be interested in. Official releases are also
66 available from the DENX file server through HTTPS or FTP.
67 https://ftp.denx.de/pub/u-boot/
68 ftp://ftp.denx.de/pub/u-boot/
74 - start from 8xxrom sources
75 - create PPCBoot project (https://sourceforge.net/projects/ppcboot)
77 - make it easier to add custom boards
78 - make it possible to add other [PowerPC] CPUs
79 - extend functions, especially:
80 * Provide extended interface to Linux boot loader
83 * ATA disk / SCSI ... boot
84 - create ARMBoot project (https://sourceforge.net/projects/armboot)
85 - add other CPU families (starting with ARM)
86 - create U-Boot project (https://sourceforge.net/projects/u-boot)
87 - current project page: see https://www.denx.de/wiki/U-Boot
93 The "official" name of this project is "Das U-Boot". The spelling
94 "U-Boot" shall be used in all written text (documentation, comments
95 in source files etc.). Example:
97 This is the README file for the U-Boot project.
99 File names etc. shall be based on the string "u-boot". Examples:
101 include/asm-ppc/u-boot.h
103 #include <asm/u-boot.h>
105 Variable names, preprocessor constants etc. shall be either based on
106 the string "u_boot" or on "U_BOOT". Example:
108 U_BOOT_VERSION u_boot_logo
109 IH_OS_U_BOOT u_boot_hush_start
115 Starting with the release in October 2008, the names of the releases
116 were changed from numerical release numbers without deeper meaning
117 into a time stamp based numbering. Regular releases are identified by
118 names consisting of the calendar year and month of the release date.
119 Additional fields (if present) indicate release candidates or bug fix
120 releases in "stable" maintenance trees.
123 U-Boot v2009.11 - Release November 2009
124 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
125 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
131 /arch Architecture-specific files
132 /arc Files generic to ARC architecture
133 /arm Files generic to ARM architecture
134 /m68k Files generic to m68k architecture
135 /microblaze Files generic to microblaze architecture
136 /mips Files generic to MIPS architecture
137 /nios2 Files generic to Altera NIOS2 architecture
138 /powerpc Files generic to PowerPC architecture
139 /riscv Files generic to RISC-V architecture
140 /sandbox Files generic to HW-independent "sandbox"
141 /sh Files generic to SH architecture
142 /x86 Files generic to x86 architecture
143 /xtensa Files generic to Xtensa architecture
144 /api Machine/arch-independent API for external apps
145 /board Board-dependent files
146 /boot Support for images and booting
147 /cmd U-Boot commands functions
148 /common Misc architecture-independent functions
149 /configs Board default configuration files
150 /disk Code for disk drive partition handling
151 /doc Documentation (a mix of ReST and READMEs)
152 /drivers Device drivers
153 /dts Makefile for building internal U-Boot fdt.
154 /env Environment support
155 /examples Example code for standalone applications, etc.
156 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
157 /include Header Files
158 /lib Library routines generic to all architectures
159 /Licenses Various license files
161 /post Power On Self Test
162 /scripts Various build scripts and Makefiles
163 /test Various unit test files
164 /tools Tools to build and sign FIT images, etc.
166 Software Configuration:
167 =======================
169 Selection of Processor Architecture and Board Type:
170 ---------------------------------------------------
172 For all supported boards there are ready-to-use default
173 configurations available; just type "make <board_name>_defconfig".
175 Example: For a TQM823L module type:
178 make TQM823L_defconfig
180 Note: If you're looking for the default configuration file for a board
181 you're sure used to be there but is now missing, check the file
182 doc/README.scrapyard for a list of no longer supported boards.
187 U-Boot can be built natively to run on a Linux host using the 'sandbox'
188 board. This allows feature development which is not board- or architecture-
189 specific to be undertaken on a native platform. The sandbox is also used to
190 run some of U-Boot's tests.
192 See doc/arch/sandbox.rst for more details.
195 Board Initialisation Flow:
196 --------------------------
198 This is the intended start-up flow for boards. This should apply for both
199 SPL and U-Boot proper (i.e. they both follow the same rules).
201 Note: "SPL" stands for "Secondary Program Loader," which is explained in
202 more detail later in this file.
204 At present, SPL mostly uses a separate code path, but the function names
205 and roles of each function are the same. Some boards or architectures
206 may not conform to this. At least most ARM boards which use
207 CONFIG_SPL_FRAMEWORK conform to this.
209 Execution typically starts with an architecture-specific (and possibly
210 CPU-specific) start.S file, such as:
212 - arch/arm/cpu/armv7/start.S
213 - arch/powerpc/cpu/mpc83xx/start.S
214 - arch/mips/cpu/start.S
216 and so on. From there, three functions are called; the purpose and
217 limitations of each of these functions are described below.
220 - purpose: essential init to permit execution to reach board_init_f()
221 - no global_data or BSS
222 - there is no stack (ARMv7 may have one but it will soon be removed)
223 - must not set up SDRAM or use console
224 - must only do the bare minimum to allow execution to continue to
226 - this is almost never needed
227 - return normally from this function
230 - purpose: set up the machine ready for running board_init_r():
231 i.e. SDRAM and serial UART
232 - global_data is available
234 - BSS is not available, so you cannot use global/static variables,
235 only stack variables and global_data
237 Non-SPL-specific notes:
238 - dram_init() is called to set up DRAM. If already done in SPL this
242 - you can override the entire board_init_f() function with your own
244 - preloader_console_init() can be called here in extremis
245 - should set up SDRAM, and anything needed to make the UART work
246 - there is no need to clear BSS, it will be done by crt0.S
247 - for specific scenarios on certain architectures an early BSS *can*
248 be made available (via CONFIG_SPL_EARLY_BSS by moving the clearing
249 of BSS prior to entering board_init_f()) but doing so is discouraged.
250 Instead it is strongly recommended to architect any code changes
251 or additions such to not depend on the availability of BSS during
252 board_init_f() as indicated in other sections of this README to
253 maintain compatibility and consistency across the entire code base.
254 - must return normally from this function (don't call board_init_r()
257 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
258 this point the stack and global_data are relocated to below
259 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
263 - purpose: main execution, common code
264 - global_data is available
266 - BSS is available, all static/global variables can be used
267 - execution eventually continues to main_loop()
269 Non-SPL-specific notes:
270 - U-Boot is relocated to the top of memory and is now running from
274 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
275 CONFIG_SYS_FSL_HAS_CCI400
277 Defined For SoC that has cache coherent interconnect
280 CONFIG_SYS_FSL_HAS_CCN504
282 Defined for SoC that has cache coherent interconnect CCN-504
284 The following options need to be configured:
286 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
288 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
293 Specifies that the core is a 64-bit PowerPC implementation (implements
294 the "64" category of the Power ISA). This is necessary for ePAPR
295 compliance, among other possible reasons.
297 CONFIG_SYS_FSL_TBCLK_DIV
299 Defines the core time base clock divider ratio compared to the
300 system clock. On most PQ3 devices this is 8, on newer QorIQ
301 devices it can be 16 or 32. The ratio varies from SoC to Soc.
303 CONFIG_SYS_FSL_PCIE_COMPAT
305 Defines the string to utilize when trying to match PCIe device
306 tree nodes for the given platform.
308 CONFIG_SYS_FSL_ERRATUM_A004510
310 Enables a workaround for erratum A004510. If set,
311 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
312 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
314 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
315 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
317 Defines one or two SoC revisions (low 8 bits of SVR)
318 for which the A004510 workaround should be applied.
320 The rest of SVR is either not relevant to the decision
321 of whether the erratum is present (e.g. p2040 versus
322 p2041) or is implied by the build target, which controls
323 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
325 See Freescale App Note 4493 for more information about
328 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
330 This is the value to write into CCSR offset 0x18600
331 according to the A004510 workaround.
333 CONFIG_SYS_FSL_DSP_DDR_ADDR
334 This value denotes start offset of DDR memory which is
335 connected exclusively to the DSP cores.
337 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
338 This value denotes start offset of M2 memory
339 which is directly connected to the DSP core.
341 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
342 This value denotes start offset of M3 memory which is directly
343 connected to the DSP core.
345 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
346 This value denotes start offset of DSP CCSR space.
348 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
349 Single Source Clock is clocking mode present in some of FSL SoC's.
350 In this mode, a single differential clock is used to supply
351 clocks to the sysclock, ddrclock and usbclock.
353 - Generic CPU options:
354 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
356 Defines the endianess of the CPU. Implementation of those
357 values is arch specific.
360 Freescale DDR driver in use. This type of DDR controller is
361 found in mpc83xx, mpc85xx as well as some ARM core SoCs.
363 CONFIG_SYS_FSL_DDR_ADDR
364 Freescale DDR memory-mapped register base.
366 CONFIG_SYS_FSL_DDRC_GEN1
367 Freescale DDR1 controller.
369 CONFIG_SYS_FSL_DDRC_GEN2
370 Freescale DDR2 controller.
372 CONFIG_SYS_FSL_DDRC_GEN3
373 Freescale DDR3 controller.
375 CONFIG_SYS_FSL_DDRC_GEN4
376 Freescale DDR4 controller.
378 CONFIG_SYS_FSL_DDRC_ARM_GEN3
379 Freescale DDR3 controller for ARM-based SoCs.
382 Board config to use DDR1. It can be enabled for SoCs with
383 Freescale DDR1 or DDR2 controllers, depending on the board
387 Board config to use DDR2. It can be enabled for SoCs with
388 Freescale DDR2 or DDR3 controllers, depending on the board
392 Board config to use DDR3. It can be enabled for SoCs with
393 Freescale DDR3 or DDR3L controllers.
396 Board config to use DDR3L. It can be enabled for SoCs with
399 CONFIG_SYS_FSL_IFC_BE
400 Defines the IFC controller register space as Big Endian
402 CONFIG_SYS_FSL_IFC_LE
403 Defines the IFC controller register space as Little Endian
405 CONFIG_SYS_FSL_IFC_CLK_DIV
406 Defines divider of platform clock(clock input to IFC controller).
408 CONFIG_SYS_FSL_LBC_CLK_DIV
409 Defines divider of platform clock(clock input to eLBC controller).
411 CONFIG_SYS_FSL_DDR_BE
412 Defines the DDR controller register space as Big Endian
414 CONFIG_SYS_FSL_DDR_LE
415 Defines the DDR controller register space as Little Endian
417 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
418 Physical address from the view of DDR controllers. It is the
419 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
420 it could be different for ARM SoCs.
422 CONFIG_SYS_FSL_DDR_INTLV_256B
423 DDR controller interleaving on 256-byte. This is a special
424 interleaving mode, handled by Dickens for Freescale layerscape
427 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
428 Number of controllers used as main memory.
430 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
431 Number of controllers used for other than main memory.
433 CONFIG_SYS_FSL_SEC_BE
434 Defines the SEC controller register space as Big Endian
436 CONFIG_SYS_FSL_SEC_LE
437 Defines the SEC controller register space as Little Endian
440 CONFIG_XWAY_SWAP_BYTES
442 Enable compilation of tools/xway-swap-bytes needed for Lantiq
443 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
444 be swapped if a flash programmer is used.
447 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
449 Select high exception vectors of the ARM core, e.g., do not
450 clear the V bit of the c1 register of CP15.
453 Generic timer clock source frequency.
455 COUNTER_FREQUENCY_REAL
456 Generic timer clock source frequency if the real clock is
457 different from COUNTER_FREQUENCY, and can only be determined
461 CONFIG_TEGRA_SUPPORT_NON_SECURE
463 Support executing U-Boot in non-secure (NS) mode. Certain
464 impossible actions will be skipped if the CPU is in NS mode,
465 such as ARM architectural timer initialization.
467 - Linux Kernel Interface:
468 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
470 When transferring memsize parameter to Linux, some versions
471 expect it to be in bytes, others in MB.
472 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
476 New kernel versions are expecting firmware settings to be
477 passed using flattened device trees (based on open firmware
481 * New libfdt-based support
482 * Adds the "fdt" command
483 * The bootm command automatically updates the fdt
485 OF_TBCLK - The timebase frequency.
487 boards with QUICC Engines require OF_QE to set UCC MAC
492 U-Boot can detect if an IDE device is present or not.
493 If not, and this new config option is activated, U-Boot
494 removes the ATA node from the DTS before booting Linux,
495 so the Linux IDE driver does not probe the device and
496 crash. This is needed for buggy hardware (uc101) where
497 no pull down resistor is connected to the signal IDE5V_DD7.
499 - vxWorks boot parameters:
501 bootvx constructs a valid bootline using the following
502 environments variables: bootdev, bootfile, ipaddr, netmask,
503 serverip, gatewayip, hostname, othbootargs.
504 It loads the vxWorks image pointed bootfile.
506 Note: If a "bootargs" environment is defined, it will override
507 the defaults discussed just above.
509 - Cache Configuration for ARM:
510 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
512 CONFIG_SYS_PL310_BASE - Physical base address of PL310
513 controller register space
518 If you have Amba PrimeCell PL011 UARTs, set this variable to
519 the clock speed of the UARTs.
523 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
524 define this to a list of base addresses for each (supported)
525 port. See e.g. include/configs/versatile.h
527 CONFIG_SERIAL_HW_FLOW_CONTROL
529 Define this variable to enable hw flow control in serial driver.
530 Current user of this option is drivers/serial/nsl16550.c driver
532 - Serial Download Echo Mode:
534 If defined to 1, all characters received during a
535 serial download (using the "loads" command) are
536 echoed back. This might be needed by some terminal
537 emulations (like "cu"), but may as well just take
538 time on others. This setting #define's the initial
539 value of the "loads_echo" environment variable.
541 - Removal of commands
542 If no commands are needed to boot, you can disable
543 CONFIG_CMDLINE to remove them. In this case, the command line
544 will not be available, and when U-Boot wants to execute the
545 boot command (on start-up) it will call board_run_command()
546 instead. This can reduce image size significantly for very
547 simple boot procedures.
549 - Regular expression support:
551 If this variable is defined, U-Boot is linked against
552 the SLRE (Super Light Regular Expression) library,
553 which adds regex support to some commands, as for
554 example "env grep" and "setexpr".
557 CONFIG_SYS_WATCHDOG_FREQ
558 Some platforms automatically call WATCHDOG_RESET()
559 from the timer interrupt handler every
560 CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
561 board configuration file, a default of CONFIG_SYS_HZ/2
562 (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
563 to 0 disables calling WATCHDOG_RESET() from the timer
568 When CONFIG_CMD_DATE is selected, the type of the RTC
569 has to be selected, too. Define exactly one of the
572 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
573 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
574 CONFIG_RTC_MC146818 - use MC146818 RTC
575 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
576 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
577 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
578 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
579 CONFIG_RTC_DS164x - use Dallas DS164x RTC
580 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
581 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
582 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
583 CONFIG_SYS_RV3029_TCR - enable trickle charger on
586 Note that if the RTC uses I2C, then the I2C interface
587 must also be configured. See I2C Support, below.
590 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
592 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
593 chip-ngpio pairs that tell the PCA953X driver the number of
594 pins supported by a particular chip.
596 Note that if the GPIO device uses I2C, then the I2C interface
597 must also be configured. See I2C Support, below.
600 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
601 accesses and can checksum them or write a list of them out
602 to memory. See the 'iotrace' command for details. This is
603 useful for testing device drivers since it can confirm that
604 the driver behaves the same way before and after a code
605 change. Currently this is supported on sandbox and arm. To
606 add support for your architecture, add '#include <iotrace.h>'
607 to the bottom of arch/<arch>/include/asm/io.h and test.
609 Example output from the 'iotrace stats' command is below.
610 Note that if the trace buffer is exhausted, the checksum will
611 still continue to operate.
614 Start: 10000000 (buffer start address)
615 Size: 00010000 (buffer size)
616 Offset: 00000120 (current buffer offset)
617 Output: 10000120 (start + offset)
618 Count: 00000018 (number of trace records)
619 CRC32: 9526fb66 (CRC32 of all trace records)
623 When CONFIG_TIMESTAMP is selected, the timestamp
624 (date and time) of an image is printed by image
625 commands like bootm or iminfo. This option is
626 automatically enabled when you select CONFIG_CMD_DATE .
628 - Partition Labels (disklabels) Supported:
629 Zero or more of the following:
630 CONFIG_MAC_PARTITION Apple's MacOS partition table.
631 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
632 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
633 bootloader. Note 2TB partition limit; see
635 CONFIG_SCSI) you must configure support for at
636 least one non-MTD partition type as well.
638 - NETWORK Support (PCI):
640 Utility code for direct access to the SPI bus on Intel 8257x.
641 This does not do anything useful unless you set at least one
642 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
645 Support for National dp83815 chips.
648 Support for National dp8382[01] gigabit chips.
650 - NETWORK Support (other):
652 Support for the Calxeda XGMAC device
655 Support for SMSC's LAN91C96 chips.
657 CONFIG_LAN91C96_USE_32_BIT
658 Define this to enable 32 bit addressing
661 Support for SMSC's LAN91C111 chip
664 Define this to hold the physical address
665 of the device (I/O space)
667 CONFIG_SMC_USE_32_BIT
668 Define this if data bus is 32 bits
670 CONFIG_SMC_USE_IOFUNCS
671 Define this to use i/o functions instead of macros
672 (some hardware wont work with macros)
674 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
675 Define this if you have more then 3 PHYs.
678 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
680 CONFIG_FTGMAC100_EGIGA
681 Define this to use GE link update with gigabit PHY.
682 Define this if FTGMAC100 is connected to gigabit PHY.
683 If your system has 10/100 PHY only, it might not occur
684 wrong behavior. Because PHY usually return timeout or
685 useless data when polling gigabit status and gigabit
686 control registers. This behavior won't affect the
687 correctnessof 10/100 link speed update.
690 Support for Renesas on-chip Ethernet controller
692 CONFIG_SH_ETHER_USE_PORT
693 Define the number of ports to be used
695 CONFIG_SH_ETHER_PHY_ADDR
696 Define the ETH PHY's address
698 CONFIG_SH_ETHER_CACHE_WRITEBACK
699 If this option is set, the driver enables cache flush.
705 CONFIG_TPM_TIS_INFINEON
706 Support for Infineon i2c bus TPM devices. Only one device
707 per system is supported at this time.
709 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
710 Define the burst count bytes upper limit
713 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
715 CONFIG_TPM_ST33ZP24_I2C
716 Support for STMicroelectronics ST33ZP24 I2C devices.
717 Requires TPM_ST33ZP24 and I2C.
719 CONFIG_TPM_ST33ZP24_SPI
720 Support for STMicroelectronics ST33ZP24 SPI devices.
721 Requires TPM_ST33ZP24 and SPI.
724 Support for Atmel TWI TPM device. Requires I2C support.
727 Support for generic parallel port TPM devices. Only one device
728 per system is supported at this time.
730 CONFIG_TPM_TIS_BASE_ADDRESS
731 Base address where the generic TPM device is mapped
732 to. Contemporary x86 systems usually map it at
736 Define this to enable the TPM support library which provides
737 functional interfaces to some TPM commands.
738 Requires support for a TPM device.
740 CONFIG_TPM_AUTH_SESSIONS
741 Define this to enable authorized functions in the TPM library.
742 Requires CONFIG_TPM and CONFIG_SHA1.
745 At the moment only the UHCI host controller is
746 supported (PIP405, MIP405); define
747 CONFIG_USB_UHCI to enable it.
748 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
749 and define CONFIG_USB_STORAGE to enable the USB
752 Supported are USB Keyboards and USB Floppy drives
755 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
759 Define the below if you wish to use the USB console.
760 Once firmware is rebuilt from a serial console issue the
761 command "setenv stdin usbtty; setenv stdout usbtty" and
762 attach your USB cable. The Unix command "dmesg" should print
763 it has found a new device. The environment variable usbtty
764 can be set to gserial or cdc_acm to enable your device to
765 appear to a USB host as a Linux gserial device or a
766 Common Device Class Abstract Control Model serial device.
767 If you select usbtty = gserial you should be able to enumerate
769 # modprobe usbserial vendor=0xVendorID product=0xProductID
770 else if using cdc_acm, simply setting the environment
771 variable usbtty to be cdc_acm should suffice. The following
772 might be defined in YourBoardName.h
775 Define this to build a UDC device
778 Define this to have a tty type of device available to
779 talk to the UDC device
782 Define this to enable the high speed support for usb
783 device and usbtty. If this feature is enabled, a routine
784 int is_usbd_high_speed(void)
785 also needs to be defined by the driver to dynamically poll
786 whether the enumeration has succeded at high speed or full
789 If you have a USB-IF assigned VendorID then you may wish to
790 define your own vendor specific values either in BoardName.h
791 or directly in usbd_vendor_info.h. If you don't define
792 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
793 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
794 should pretend to be a Linux device to it's target host.
796 CONFIG_USBD_MANUFACTURER
797 Define this string as the name of your company for
798 - CONFIG_USBD_MANUFACTURER "my company"
800 CONFIG_USBD_PRODUCT_NAME
801 Define this string as the name of your product
802 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
805 Define this as your assigned Vendor ID from the USB
806 Implementors Forum. This *must* be a genuine Vendor ID
807 to avoid polluting the USB namespace.
808 - CONFIG_USBD_VENDORID 0xFFFF
810 CONFIG_USBD_PRODUCTID
811 Define this as the unique Product ID
813 - CONFIG_USBD_PRODUCTID 0xFFFF
815 - ULPI Layer Support:
816 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
817 the generic ULPI layer. The generic layer accesses the ULPI PHY
818 via the platform viewport, so you need both the genric layer and
819 the viewport enabled. Currently only Chipidea/ARC based
820 viewport is supported.
821 To enable the ULPI layer support, define CONFIG_USB_ULPI and
822 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
823 If your ULPI phy needs a different reference clock than the
824 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
825 the appropriate value in Hz.
829 Support for Renesas on-chip MMCIF controller
832 Define the base address of MMCIF registers
835 Define the clock frequency for MMCIF
837 - USB Device Firmware Update (DFU) class support:
839 This enables the USB portion of the DFU USB class
842 This enables support for exposing NAND devices via DFU.
845 This enables support for exposing RAM via DFU.
846 Note: DFU spec refer to non-volatile memory usage, but
847 allow usages beyond the scope of spec - here RAM usage,
848 one that would help mostly the developer.
850 CONFIG_SYS_DFU_DATA_BUF_SIZE
851 Dfu transfer uses a buffer before writing data to the
852 raw storage device. Make the size (in bytes) of this buffer
853 configurable. The size of this buffer is also configurable
854 through the "dfu_bufsiz" environment variable.
856 CONFIG_SYS_DFU_MAX_FILE_SIZE
857 When updating files rather than the raw storage device,
858 we use a static buffer to copy the file into and then write
859 the buffer once we've been given the whole file. Define
860 this to the maximum filesize (in bytes) for the buffer.
861 Default is 4 MiB if undefined.
863 DFU_DEFAULT_POLL_TIMEOUT
864 Poll timeout [ms], is the timeout a device can send to the
865 host. The host must wait for this timeout before sending
866 a subsequent DFU_GET_STATUS request to the device.
868 DFU_MANIFEST_POLL_TIMEOUT
869 Poll timeout [ms], which the device sends to the host when
870 entering dfuMANIFEST state. Host waits this timeout, before
871 sending again an USB request to the device.
873 - Journaling Flash filesystem support:
874 CONFIG_SYS_JFFS2_FIRST_SECTOR,
875 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
876 Define these for a default partition on a NOR device
879 See Kconfig help for available keyboard drivers.
881 - LCD Support: CONFIG_LCD
883 Define this to enable LCD support (for output to LCD
884 display); also select one of the supported displays
885 by defining one of these:
887 CONFIG_NEC_NL6448AC33:
889 NEC NL6448AC33-18. Active, color, single scan.
891 CONFIG_NEC_NL6448BC20
893 NEC NL6448BC20-08. 6.5", 640x480.
894 Active, color, single scan.
896 CONFIG_NEC_NL6448BC33_54
898 NEC NL6448BC33-54. 10.4", 640x480.
899 Active, color, single scan.
903 Sharp 320x240. Active, color, single scan.
904 It isn't 16x9, and I am not sure what it is.
906 CONFIG_SHARP_LQ64D341
908 Sharp LQ64D341 display, 640x480.
909 Active, color, single scan.
913 HLD1045 display, 640x480.
914 Active, color, single scan.
918 Optrex CBL50840-2 NF-FW 99 22 M5
920 Hitachi LMG6912RPFC-00T
924 320x240. Black & white.
928 Normally the LCD is page-aligned (typically 4KB). If this is
929 defined then the LCD will be aligned to this value instead.
930 For ARM it is sometimes useful to use MMU_SECTION_SIZE
931 here, since it is cheaper to change data cache settings on
937 Sometimes, for example if the display is mounted in portrait
938 mode or even if it's mounted landscape but rotated by 180degree,
939 we need to rotate our content of the display relative to the
940 framebuffer, so that user can read the messages which are
942 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
943 initialized with a given rotation from "vl_rot" out of
944 "vidinfo_t" which is provided by the board specific code.
945 The value for vl_rot is coded as following (matching to
946 fbcon=rotate:<n> linux-kernel commandline):
947 0 = no rotation respectively 0 degree
948 1 = 90 degree rotation
949 2 = 180 degree rotation
950 3 = 270 degree rotation
952 If CONFIG_LCD_ROTATION is not defined, the console will be
953 initialized with 0degree rotation.
956 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
958 The clock frequency of the MII bus
960 CONFIG_PHY_CMD_DELAY (ppc4xx)
962 Some PHY like Intel LXT971A need extra delay after
963 command issued before MII status register can be read
968 Define a default value for the IP address to use for
969 the default Ethernet interface, in case this is not
970 determined through e.g. bootp.
971 (Environment variable "ipaddr")
976 Defines a default value for the IP address of a TFTP
977 server to contact when using the "tftboot" command.
978 (Environment variable "serverip")
980 - Gateway IP address:
983 Defines a default value for the IP address of the
984 default router where packets to other networks are
986 (Environment variable "gatewayip")
991 Defines a default value for the subnet mask (or
992 routing prefix) which is used to determine if an IP
993 address belongs to the local subnet or needs to be
994 forwarded through a router.
995 (Environment variable "netmask")
997 - BOOTP Recovery Mode:
998 CONFIG_BOOTP_RANDOM_DELAY
1000 If you have many targets in a network that try to
1001 boot using BOOTP, you may want to avoid that all
1002 systems send out BOOTP requests at precisely the same
1003 moment (which would happen for instance at recovery
1004 from a power failure, when all systems will try to
1005 boot, thus flooding the BOOTP server. Defining
1006 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1007 inserted before sending out BOOTP requests. The
1008 following delays are inserted then:
1010 1st BOOTP request: delay 0 ... 1 sec
1011 2nd BOOTP request: delay 0 ... 2 sec
1012 3rd BOOTP request: delay 0 ... 4 sec
1014 BOOTP requests: delay 0 ... 8 sec
1016 CONFIG_BOOTP_ID_CACHE_SIZE
1018 BOOTP packets are uniquely identified using a 32-bit ID. The
1019 server will copy the ID from client requests to responses and
1020 U-Boot will use this to determine if it is the destination of
1021 an incoming response. Some servers will check that addresses
1022 aren't in use before handing them out (usually using an ARP
1023 ping) and therefore take up to a few hundred milliseconds to
1024 respond. Network congestion may also influence the time it
1025 takes for a response to make it back to the client. If that
1026 time is too long, U-Boot will retransmit requests. In order
1027 to allow earlier responses to still be accepted after these
1028 retransmissions, U-Boot's BOOTP client keeps a small cache of
1029 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1030 cache. The default is to keep IDs for up to four outstanding
1031 requests. Increasing this will allow U-Boot to accept offers
1032 from a BOOTP client in networks with unusually high latency.
1034 - DHCP Advanced Options:
1036 - Link-local IP address negotiation:
1037 Negotiate with other link-local clients on the local network
1038 for an address that doesn't require explicit configuration.
1039 This is especially useful if a DHCP server cannot be guaranteed
1040 to exist in all environments that the device must operate.
1042 See doc/README.link-local for more information.
1044 - MAC address from environment variables
1046 FDT_SEQ_MACADDR_FROM_ENV
1048 Fix-up device tree with MAC addresses fetched sequentially from
1049 environment variables. This config work on assumption that
1050 non-usable ethernet node of device-tree are either not present
1051 or their status has been marked as "disabled".
1054 CONFIG_CDP_DEVICE_ID
1056 The device id used in CDP trigger frames.
1058 CONFIG_CDP_DEVICE_ID_PREFIX
1060 A two character string which is prefixed to the MAC address
1065 A printf format string which contains the ascii name of
1066 the port. Normally is set to "eth%d" which sets
1067 eth0 for the first Ethernet, eth1 for the second etc.
1069 CONFIG_CDP_CAPABILITIES
1071 A 32bit integer which indicates the device capabilities;
1072 0x00000010 for a normal host which does not forwards.
1076 An ascii string containing the version of the software.
1080 An ascii string containing the name of the platform.
1084 A 32bit integer sent on the trigger.
1086 CONFIG_CDP_POWER_CONSUMPTION
1088 A 16bit integer containing the power consumption of the
1089 device in .1 of milliwatts.
1091 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1093 A byte containing the id of the VLAN.
1095 - Status LED: CONFIG_LED_STATUS
1097 Several configurations allow to display the current
1098 status using a LED. For instance, the LED will blink
1099 fast while running U-Boot code, stop blinking as
1100 soon as a reply to a BOOTP request was received, and
1101 start blinking slow once the Linux kernel is running
1102 (supported by a status LED driver in the Linux
1103 kernel). Defining CONFIG_LED_STATUS enables this
1108 CONFIG_LED_STATUS_GPIO
1109 The status LED can be connected to a GPIO pin.
1110 In such cases, the gpio_led driver can be used as a
1111 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1112 to include the gpio_led driver in the U-Boot binary.
1114 CONFIG_GPIO_LED_INVERTED_TABLE
1115 Some GPIO connected LEDs may have inverted polarity in which
1116 case the GPIO high value corresponds to LED off state and
1117 GPIO low value corresponds to LED on state.
1118 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1119 with a list of GPIO LEDs that have inverted polarity.
1122 CONFIG_SYS_NUM_I2C_BUSES
1123 Hold the number of i2c buses you want to use.
1125 CONFIG_SYS_I2C_DIRECT_BUS
1126 define this, if you don't use i2c muxes on your hardware.
1127 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1130 CONFIG_SYS_I2C_MAX_HOPS
1131 define how many muxes are maximal consecutively connected
1132 on one i2c bus. If you not use i2c muxes, omit this
1135 CONFIG_SYS_I2C_BUSES
1136 hold a list of buses you want to use, only used if
1137 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1138 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1139 CONFIG_SYS_NUM_I2C_BUSES = 9:
1141 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1142 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1143 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1144 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1145 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1146 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1147 {1, {I2C_NULL_HOP}}, \
1148 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1149 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1153 bus 0 on adapter 0 without a mux
1154 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1155 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1156 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1157 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1158 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
1159 bus 6 on adapter 1 without a mux
1160 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1161 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
1163 If you do not have i2c muxes on your board, omit this define.
1165 - Legacy I2C Support:
1166 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
1167 then the following macros need to be defined (examples are
1168 from include/configs/lwmon.h):
1172 (Optional). Any commands necessary to enable the I2C
1173 controller or configure ports.
1175 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1179 The code necessary to make the I2C data line active
1180 (driven). If the data line is open collector, this
1183 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1187 The code necessary to make the I2C data line tri-stated
1188 (inactive). If the data line is open collector, this
1191 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1195 Code that returns true if the I2C data line is high,
1198 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1202 If <bit> is true, sets the I2C data line high. If it
1203 is false, it clears it (low).
1205 eg: #define I2C_SDA(bit) \
1206 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1207 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1211 If <bit> is true, sets the I2C clock line high. If it
1212 is false, it clears it (low).
1214 eg: #define I2C_SCL(bit) \
1215 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1216 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1220 This delay is invoked four times per clock cycle so this
1221 controls the rate of data transfer. The data rate thus
1222 is 1 / (I2C_DELAY * 4). Often defined to be something
1225 #define I2C_DELAY udelay(2)
1227 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1229 If your arch supports the generic GPIO framework (asm/gpio.h),
1230 then you may alternatively define the two GPIOs that are to be
1231 used as SCL / SDA. Any of the previous I2C_xxx macros will
1232 have GPIO-based defaults assigned to them as appropriate.
1234 You should define these to the GPIO value as given directly to
1235 the generic GPIO functions.
1237 CONFIG_SYS_I2C_INIT_BOARD
1239 When a board is reset during an i2c bus transfer
1240 chips might think that the current transfer is still
1241 in progress. On some boards it is possible to access
1242 the i2c SCLK line directly, either by using the
1243 processor pin as a GPIO or by having a second pin
1244 connected to the bus. If this option is defined a
1245 custom i2c_init_board() routine in boards/xxx/board.c
1246 is run early in the boot sequence.
1248 CONFIG_I2C_MULTI_BUS
1250 This option allows the use of multiple I2C buses, each of which
1251 must have a controller. At any point in time, only one bus is
1252 active. To switch to a different bus, use the 'i2c dev' command.
1253 Note that bus numbering is zero-based.
1255 CONFIG_SYS_I2C_NOPROBES
1257 This option specifies a list of I2C devices that will be skipped
1258 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1259 is set, specify a list of bus-device pairs. Otherwise, specify
1260 a 1D array of device addresses
1263 #undef CONFIG_I2C_MULTI_BUS
1264 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1266 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1268 #define CONFIG_I2C_MULTI_BUS
1269 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1271 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1273 CONFIG_SYS_RTC_BUS_NUM
1275 If defined, then this indicates the I2C bus number for the RTC.
1276 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1278 CONFIG_SOFT_I2C_READ_REPEATED_START
1280 defining this will force the i2c_read() function in
1281 the soft_i2c driver to perform an I2C repeated start
1282 between writing the address pointer and reading the
1283 data. If this define is omitted the default behaviour
1284 of doing a stop-start sequence will be used. Most I2C
1285 devices can use either method, but some require one or
1288 - SPI Support: CONFIG_SPI
1290 Enables SPI driver (so far only tested with
1291 SPI EEPROM, also an instance works with Crystal A/D and
1292 D/As on the SACSng board)
1294 CONFIG_SYS_SPI_MXC_WAIT
1295 Timeout for waiting until spi transfer completed.
1296 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1298 - FPGA Support: CONFIG_FPGA
1300 Enables FPGA subsystem.
1302 CONFIG_FPGA_<vendor>
1304 Enables support for specific chip vendors.
1307 CONFIG_FPGA_<family>
1309 Enables support for FPGA family.
1310 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1312 CONFIG_SYS_FPGA_CHECK_BUSY
1314 Enable checks on FPGA configuration interface busy
1315 status by the configuration function. This option
1316 will require a board or device specific function to
1321 If defined, a function that provides delays in the FPGA
1322 configuration driver.
1324 CONFIG_SYS_FPGA_CHECK_ERROR
1326 Check for configuration errors during FPGA bitfile
1327 loading. For example, abort during Virtex II
1328 configuration if the INIT_B line goes low (which
1329 indicated a CRC error).
1331 CONFIG_SYS_FPGA_WAIT_INIT
1333 Maximum time to wait for the INIT_B line to de-assert
1334 after PROB_B has been de-asserted during a Virtex II
1335 FPGA configuration sequence. The default time is 500
1338 CONFIG_SYS_FPGA_WAIT_BUSY
1340 Maximum time to wait for BUSY to de-assert during
1341 Virtex II FPGA configuration. The default is 5 ms.
1343 CONFIG_SYS_FPGA_WAIT_CONFIG
1345 Time to wait after FPGA configuration. The default is
1348 - Vendor Parameter Protection:
1350 U-Boot considers the values of the environment
1351 variables "serial#" (Board Serial Number) and
1352 "ethaddr" (Ethernet Address) to be parameters that
1353 are set once by the board vendor / manufacturer, and
1354 protects these variables from casual modification by
1355 the user. Once set, these variables are read-only,
1356 and write or delete attempts are rejected. You can
1357 change this behaviour:
1359 If CONFIG_ENV_OVERWRITE is #defined in your config
1360 file, the write protection for vendor parameters is
1361 completely disabled. Anybody can change or delete
1364 Alternatively, if you define _both_ an ethaddr in the
1365 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1366 Ethernet address is installed in the environment,
1367 which can be changed exactly ONCE by the user. [The
1368 serial# is unaffected by this, i. e. it remains
1371 The same can be accomplished in a more flexible way
1372 for any variable by configuring the type of access
1373 to allow for those variables in the ".flags" variable
1374 or define CONFIG_ENV_FLAGS_LIST_STATIC.
1379 Define this variable to enable the reservation of
1380 "protected RAM", i. e. RAM which is not overwritten
1381 by U-Boot. Define CONFIG_PRAM to hold the number of
1382 kB you want to reserve for pRAM. You can overwrite
1383 this default value by defining an environment
1384 variable "pram" to the number of kB you want to
1385 reserve. Note that the board info structure will
1386 still show the full amount of RAM. If pRAM is
1387 reserved, a new environment variable "mem" will
1388 automatically be defined to hold the amount of
1389 remaining RAM in a form that can be passed as boot
1390 argument to Linux, for instance like that:
1392 setenv bootargs ... mem=\${mem}
1395 This way you can tell Linux not to use this memory,
1396 either, which results in a memory region that will
1397 not be affected by reboots.
1399 *WARNING* If your board configuration uses automatic
1400 detection of the RAM size, you must make sure that
1401 this memory test is non-destructive. So far, the
1402 following board configurations are known to be
1405 IVMS8, IVML24, SPD8xx,
1406 HERMES, IP860, RPXlite, LWMON,
1412 In the current implementation, the local variables
1413 space and global environment variables space are
1414 separated. Local variables are those you define by
1415 simply typing `name=value'. To access a local
1416 variable later on, you have write `$name' or
1417 `${name}'; to execute the contents of a variable
1418 directly type `$name' at the command prompt.
1420 Global environment variables are those you use
1421 setenv/printenv to work with. To run a command stored
1422 in such a variable, you need to use the run command,
1423 and you must not use the '$' sign to access them.
1425 To store commands and special characters in a
1426 variable, please use double quotation marks
1427 surrounding the whole text of the variable, instead
1428 of the backslashes before semicolons and special
1431 - Default Environment:
1432 CONFIG_EXTRA_ENV_SETTINGS
1434 Define this to contain any number of null terminated
1435 strings (variable = value pairs) that will be part of
1436 the default environment compiled into the boot image.
1438 For example, place something like this in your
1439 board's config file:
1441 #define CONFIG_EXTRA_ENV_SETTINGS \
1445 Warning: This method is based on knowledge about the
1446 internal format how the environment is stored by the
1447 U-Boot code. This is NOT an official, exported
1448 interface! Although it is unlikely that this format
1449 will change soon, there is no guarantee either.
1450 You better know what you are doing here.
1452 Note: overly (ab)use of the default environment is
1453 discouraged. Make sure to check other ways to preset
1454 the environment like the "source" command or the
1457 CONFIG_DELAY_ENVIRONMENT
1459 Normally the environment is loaded when the board is
1460 initialised so that it is available to U-Boot. This inhibits
1461 that so that the environment is not available until
1462 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
1463 this is instead controlled by the value of
1464 /config/load-environment.
1466 CONFIG_STANDALONE_LOAD_ADDR
1468 This option defines a board specific value for the
1469 address where standalone program gets loaded, thus
1470 overwriting the architecture dependent default
1473 - Automatic software updates via TFTP server
1475 CONFIG_UPDATE_TFTP_CNT_MAX
1476 CONFIG_UPDATE_TFTP_MSEC_MAX
1478 These options enable and control the auto-update feature;
1479 for a more detailed description refer to doc/README.update.
1481 - MTD Support (mtdparts command, UBI support)
1482 CONFIG_MTD_UBI_WL_THRESHOLD
1483 This parameter defines the maximum difference between the highest
1484 erase counter value and the lowest erase counter value of eraseblocks
1485 of UBI devices. When this threshold is exceeded, UBI starts performing
1486 wear leveling by means of moving data from eraseblock with low erase
1487 counter to eraseblocks with high erase counter.
1489 The default value should be OK for SLC NAND flashes, NOR flashes and
1490 other flashes which have eraseblock life-cycle 100000 or more.
1491 However, in case of MLC NAND flashes which typically have eraseblock
1492 life-cycle less than 10000, the threshold should be lessened (e.g.,
1493 to 128 or 256, although it does not have to be power of 2).
1497 CONFIG_MTD_UBI_BEB_LIMIT
1498 This option specifies the maximum bad physical eraseblocks UBI
1499 expects on the MTD device (per 1024 eraseblocks). If the
1500 underlying flash does not admit of bad eraseblocks (e.g. NOR
1501 flash), this value is ignored.
1503 NAND datasheets often specify the minimum and maximum NVM
1504 (Number of Valid Blocks) for the flashes' endurance lifetime.
1505 The maximum expected bad eraseblocks per 1024 eraseblocks
1506 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
1507 which gives 20 for most NANDs (MaxNVB is basically the total
1508 count of eraseblocks on the chip).
1510 To put it differently, if this value is 20, UBI will try to
1511 reserve about 1.9% of physical eraseblocks for bad blocks
1512 handling. And that will be 1.9% of eraseblocks on the entire
1513 NAND chip, not just the MTD partition UBI attaches. This means
1514 that if you have, say, a NAND flash chip admits maximum 40 bad
1515 eraseblocks, and it is split on two MTD partitions of the same
1516 size, UBI will reserve 40 eraseblocks when attaching a
1521 CONFIG_MTD_UBI_FASTMAP
1522 Fastmap is a mechanism which allows attaching an UBI device
1523 in nearly constant time. Instead of scanning the whole MTD device it
1524 only has to locate a checkpoint (called fastmap) on the device.
1525 The on-flash fastmap contains all information needed to attach
1526 the device. Using fastmap makes only sense on large devices where
1527 attaching by scanning takes long. UBI will not automatically install
1528 a fastmap on old images, but you can set the UBI parameter
1529 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
1530 that fastmap-enabled images are still usable with UBI implementations
1531 without fastmap support. On typical flash devices the whole fastmap
1532 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
1534 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
1535 Set this parameter to enable fastmap automatically on images
1539 CONFIG_MTD_UBI_FM_DEBUG
1540 Enable UBI fastmap debug
1545 Enable building of SPL globally.
1547 CONFIG_SPL_PANIC_ON_RAW_IMAGE
1548 When defined, SPL will panic() if the image it has
1549 loaded does not have a signature.
1550 Defining this is useful when code which loads images
1551 in SPL cannot guarantee that absolutely all read errors
1553 An example is the LPC32XX MLC NAND driver, which will
1554 consider that a completely unreadable NAND block is bad,
1555 and thus should be skipped silently.
1557 CONFIG_SPL_DISPLAY_PRINT
1558 For ARM, enable an optional function to print more information
1559 about the running system.
1561 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
1562 Set this for NAND SPL on PPC mpc83xx targets, so that
1563 start.S waits for the rest of the SPL to load before
1564 continuing (the hardware starts execution after just
1565 loading the first page rather than the full 4K).
1568 Support for a lightweight UBI (fastmap) scanner and
1571 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
1572 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
1573 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
1574 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
1575 CONFIG_SYS_NAND_ECCBYTES
1576 Defines the size and behavior of the NAND that SPL uses
1579 CONFIG_SYS_NAND_U_BOOT_DST
1580 Location in memory to load U-Boot to
1582 CONFIG_SYS_NAND_U_BOOT_SIZE
1583 Size of image to load
1585 CONFIG_SYS_NAND_U_BOOT_START
1586 Entry point in loaded image to jump to
1588 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
1589 Define this if you need to first read the OOB and then the
1590 data. This is used, for example, on davinci platforms.
1592 CONFIG_SPL_RAM_DEVICE
1593 Support for running image already present in ram, in SPL binary
1595 CONFIG_SPL_FIT_PRINT
1596 Printing information about a FIT image adds quite a bit of
1597 code to SPL. So this is normally disabled in SPL. Use this
1598 option to re-enable it. This will affect the output of the
1599 bootm command when booting a FIT image.
1601 - Interrupt support (PPC):
1603 There are common interrupt_init() and timer_interrupt()
1604 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1605 for CPU specific initialization. interrupt_init_cpu()
1606 should set decrementer_count to appropriate value. If
1607 CPU resets decrementer automatically after interrupt
1608 (ppc4xx) it should set decrementer_count to zero.
1609 timer_interrupt() calls timer_interrupt_cpu() for CPU
1610 specific handling. If board has watchdog / status_led
1611 / other_activity_monitor it works automatically from
1612 general timer_interrupt().
1615 Board initialization settings:
1616 ------------------------------
1618 During Initialization u-boot calls a number of board specific functions
1619 to allow the preparation of board specific prerequisites, e.g. pin setup
1620 before drivers are initialized. To enable these callbacks the
1621 following configuration macros have to be defined. Currently this is
1622 architecture specific, so please check arch/your_architecture/lib/board.c
1623 typically in board_init_f() and board_init_r().
1625 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
1626 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
1627 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
1629 Configuration Settings:
1630 -----------------------
1632 - MEM_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
1633 Optionally it can be defined to support 64-bit memory commands.
1635 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
1636 undefine this when you're short of memory.
1638 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
1639 width of the commands listed in the 'help' command output.
1641 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
1642 prompt for user input.
1644 - CONFIG_SYS_BAUDRATE_TABLE:
1645 List of legal baudrate settings for this board.
1647 - CONFIG_SYS_MEM_RESERVE_SECURE
1648 Only implemented for ARMv8 for now.
1649 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
1650 is substracted from total RAM and won't be reported to OS.
1651 This memory can be used as secure memory. A variable
1652 gd->arch.secure_ram is used to track the location. In systems
1653 the RAM base is not zero, or RAM is divided into banks,
1654 this variable needs to be recalcuated to get the address.
1656 - CONFIG_SYS_LOADS_BAUD_CHANGE:
1657 Enable temporary baudrate change while serial download
1659 - CONFIG_SYS_SDRAM_BASE:
1660 Physical start address of SDRAM. _Must_ be 0 here.
1662 - CONFIG_SYS_FLASH_BASE:
1663 Physical start address of Flash memory.
1665 - CONFIG_SYS_MONITOR_LEN:
1666 Size of memory reserved for monitor code, used to
1667 determine _at_compile_time_ (!) if the environment is
1668 embedded within the U-Boot image, or in a separate
1671 - CONFIG_SYS_MALLOC_LEN:
1672 Size of DRAM reserved for malloc() use.
1674 - CONFIG_SYS_MALLOC_F_LEN
1675 Size of the malloc() pool for use before relocation. If
1676 this is defined, then a very simple malloc() implementation
1677 will become available before relocation. The address is just
1678 below the global data, and the stack is moved down to make
1681 This feature allocates regions with increasing addresses
1682 within the region. calloc() is supported, but realloc()
1683 is not available. free() is supported but does nothing.
1684 The memory will be freed (or in fact just forgotten) when
1685 U-Boot relocates itself.
1687 - CONFIG_SYS_MALLOC_SIMPLE
1688 Provides a simple and small malloc() and calloc() for those
1689 boards which do not use the full malloc in SPL (which is
1690 enabled with CONFIG_SYS_SPL_MALLOC).
1692 - CONFIG_SYS_NONCACHED_MEMORY:
1693 Size of non-cached memory area. This area of memory will be
1694 typically located right below the malloc() area and mapped
1695 uncached in the MMU. This is useful for drivers that would
1696 otherwise require a lot of explicit cache maintenance. For
1697 some drivers it's also impossible to properly maintain the
1698 cache. For example if the regions that need to be flushed
1699 are not a multiple of the cache-line size, *and* padding
1700 cannot be allocated between the regions to align them (i.e.
1701 if the HW requires a contiguous array of regions, and the
1702 size of each region is not cache-aligned), then a flush of
1703 one region may result in overwriting data that hardware has
1704 written to another region in the same cache-line. This can
1705 happen for example in network drivers where descriptors for
1706 buffers are typically smaller than the CPU cache-line (e.g.
1707 16 bytes vs. 32 or 64 bytes).
1709 Non-cached memory is only supported on 32-bit ARM at present.
1711 - CONFIG_SYS_BOOTMAPSZ:
1712 Maximum size of memory mapped by the startup code of
1713 the Linux kernel; all data that must be processed by
1714 the Linux kernel (bd_info, boot arguments, FDT blob if
1715 used) must be put below this limit, unless "bootm_low"
1716 environment variable is defined and non-zero. In such case
1717 all data for the Linux kernel must be between "bootm_low"
1718 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
1719 variable "bootm_mapsize" will override the value of
1720 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
1721 then the value in "bootm_size" will be used instead.
1723 - CONFIG_SYS_BOOT_GET_CMDLINE:
1724 Enables allocating and saving kernel cmdline in space between
1725 "bootm_low" and "bootm_low" + BOOTMAPSZ.
1727 - CONFIG_SYS_BOOT_GET_KBD:
1728 Enables allocating and saving a kernel copy of the bd_info in
1729 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
1731 - CONFIG_SYS_MAX_FLASH_SECT:
1732 Max number of sectors on a Flash chip
1734 - CONFIG_SYS_FLASH_ERASE_TOUT:
1735 Timeout for Flash erase operations (in ms)
1737 - CONFIG_SYS_FLASH_WRITE_TOUT:
1738 Timeout for Flash write operations (in ms)
1740 - CONFIG_SYS_FLASH_LOCK_TOUT
1741 Timeout for Flash set sector lock bit operation (in ms)
1743 - CONFIG_SYS_FLASH_UNLOCK_TOUT
1744 Timeout for Flash clear lock bits operation (in ms)
1746 - CONFIG_SYS_FLASH_PROTECTION
1747 If defined, hardware flash sectors protection is used
1748 instead of U-Boot software protection.
1750 - CONFIG_SYS_FLASH_CFI:
1751 Define if the flash driver uses extra elements in the
1752 common flash structure for storing flash geometry.
1754 - CONFIG_FLASH_CFI_DRIVER
1755 This option also enables the building of the cfi_flash driver
1756 in the drivers directory
1758 - CONFIG_FLASH_CFI_MTD
1759 This option enables the building of the cfi_mtd driver
1760 in the drivers directory. The driver exports CFI flash
1763 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
1764 Use buffered writes to flash.
1766 - CONFIG_FLASH_SPANSION_S29WS_N
1767 s29ws-n MirrorBit flash has non-standard addresses for buffered
1770 - CONFIG_SYS_FLASH_QUIET_TEST
1771 If this option is defined, the common CFI flash doesn't
1772 print it's warning upon not recognized FLASH banks. This
1773 is useful, if some of the configured banks are only
1774 optionally available.
1776 - CONFIG_FLASH_SHOW_PROGRESS
1777 If defined (must be an integer), print out countdown
1778 digits and dots. Recommended value: 45 (9..1) for 80
1779 column displays, 15 (3..1) for 40 column displays.
1781 - CONFIG_FLASH_VERIFY
1782 If defined, the content of the flash (destination) is compared
1783 against the source after the write operation. An error message
1784 will be printed when the contents are not identical.
1785 Please note that this option is useless in nearly all cases,
1786 since such flash programming errors usually are detected earlier
1787 while unprotecting/erasing/programming. Please only enable
1788 this option if you really know what you are doing.
1790 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1791 - CONFIG_ENV_FLAGS_LIST_STATIC
1792 Enable validation of the values given to environment variables when
1793 calling env set. Variables can be restricted to only decimal,
1794 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
1795 the variables can also be restricted to IP address or MAC address.
1797 The format of the list is:
1798 type_attribute = [s|d|x|b|i|m]
1799 access_attribute = [a|r|o|c]
1800 attributes = type_attribute[access_attribute]
1801 entry = variable_name[:attributes]
1804 The type attributes are:
1805 s - String (default)
1808 b - Boolean ([1yYtT|0nNfF])
1812 The access attributes are:
1818 - CONFIG_ENV_FLAGS_LIST_DEFAULT
1819 Define this to a list (string) to define the ".flags"
1820 environment variable in the default or embedded environment.
1822 - CONFIG_ENV_FLAGS_LIST_STATIC
1823 Define this to a list (string) to define validation that
1824 should be done if an entry is not found in the ".flags"
1825 environment variable. To override a setting in the static
1826 list, simply add an entry for the same variable name to the
1829 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
1830 regular expression. This allows multiple variables to define the same
1831 flags without explicitly listing them for each variable.
1833 The following definitions that deal with the placement and management
1834 of environment data (variable area); in general, we support the
1835 following configurations:
1837 - CONFIG_BUILD_ENVCRC:
1839 Builds up envcrc with the target environment so that external utils
1840 may easily extract it and embed it in final U-Boot images.
1842 BE CAREFUL! The first access to the environment happens quite early
1843 in U-Boot initialization (when we try to get the setting of for the
1844 console baudrate). You *MUST* have mapped your NVRAM area then, or
1847 Please note that even with NVRAM we still use a copy of the
1848 environment in RAM: we could work on NVRAM directly, but we want to
1849 keep settings there always unmodified except somebody uses "saveenv"
1850 to save the current settings.
1852 BE CAREFUL! For some special cases, the local device can not use
1853 "saveenv" command. For example, the local device will get the
1854 environment stored in a remote NOR flash by SRIO or PCIE link,
1855 but it can not erase, write this NOR flash by SRIO or PCIE interface.
1857 - CONFIG_NAND_ENV_DST
1859 Defines address in RAM to which the nand_spl code should copy the
1860 environment. If redundant environment is used, it will be copied to
1861 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
1863 Please note that the environment is read-only until the monitor
1864 has been relocated to RAM and a RAM copy of the environment has been
1865 created; also, when using EEPROM you will have to use env_get_f()
1866 until then to read environment variables.
1868 The environment is protected by a CRC32 checksum. Before the monitor
1869 is relocated into RAM, as a result of a bad CRC you will be working
1870 with the compiled-in default environment - *silently*!!! [This is
1871 necessary, because the first environment variable we need is the
1872 "baudrate" setting for the console - if we have a bad CRC, we don't
1873 have any device yet where we could complain.]
1875 Note: once the monitor has been relocated, then it will complain if
1876 the default environment is used; a new CRC is computed as soon as you
1877 use the "saveenv" command to store a valid environment.
1879 - CONFIG_SYS_FAULT_MII_ADDR:
1880 MII address of the PHY to check for the Ethernet link state.
1882 - CONFIG_NS16550_MIN_FUNCTIONS:
1883 Define this if you desire to only have use of the NS16550_init
1884 and NS16550_putc functions for the serial driver located at
1885 drivers/serial/ns16550.c. This option is useful for saving
1886 space for already greatly restricted images, including but not
1887 limited to NAND_SPL configurations.
1889 - CONFIG_DISPLAY_BOARDINFO
1890 Display information about the board that U-Boot is running on
1891 when U-Boot starts up. The board function checkboard() is called
1894 - CONFIG_DISPLAY_BOARDINFO_LATE
1895 Similar to the previous option, but display this information
1896 later, once stdio is running and output goes to the LCD, if
1899 Low Level (hardware related) configuration options:
1900 ---------------------------------------------------
1902 - CONFIG_SYS_CACHELINE_SIZE:
1903 Cache Line Size of the CPU.
1905 - CONFIG_SYS_CCSRBAR_DEFAULT:
1906 Default (power-on reset) physical address of CCSR on Freescale
1909 - CONFIG_SYS_CCSRBAR:
1910 Virtual address of CCSR. On a 32-bit build, this is typically
1911 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
1913 - CONFIG_SYS_CCSRBAR_PHYS:
1914 Physical address of CCSR. CCSR can be relocated to a new
1915 physical address, if desired. In this case, this macro should
1916 be set to that address. Otherwise, it should be set to the
1917 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
1918 is typically relocated on 36-bit builds. It is recommended
1919 that this macro be defined via the _HIGH and _LOW macros:
1921 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
1922 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
1924 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
1925 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
1926 either 0 (32-bit build) or 0xF (36-bit build). This macro is
1927 used in assembly code, so it must not contain typecasts or
1928 integer size suffixes (e.g. "ULL").
1930 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
1931 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
1932 used in assembly code, so it must not contain typecasts or
1933 integer size suffixes (e.g. "ULL").
1935 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
1936 DO NOT CHANGE unless you know exactly what you're
1937 doing! (11-4) [MPC8xx systems only]
1939 - CONFIG_SYS_INIT_RAM_ADDR:
1941 Start address of memory area that can be used for
1942 initial data and stack; please note that this must be
1943 writable memory that is working WITHOUT special
1944 initialization, i. e. you CANNOT use normal RAM which
1945 will become available only after programming the
1946 memory controller and running certain initialization
1949 U-Boot uses the following memory types:
1950 - MPC8xx: IMMR (internal memory of the CPU)
1952 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
1954 - CONFIG_SYS_OR_TIMING_SDRAM:
1957 - CONFIG_SYS_MAMR_PTA:
1958 periodic timer for refresh
1961 Chip has SRIO or not
1964 Board has SRIO 1 port available
1967 Board has SRIO 2 port available
1969 - CONFIG_SRIO_PCIE_BOOT_MASTER
1970 Board can support master function for Boot from SRIO and PCIE
1972 - CONFIG_SYS_SRIOn_MEM_VIRT:
1973 Virtual Address of SRIO port 'n' memory region
1975 - CONFIG_SYS_SRIOn_MEM_PHYxS:
1976 Physical Address of SRIO port 'n' memory region
1978 - CONFIG_SYS_SRIOn_MEM_SIZE:
1979 Size of SRIO port 'n' memory region
1981 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
1982 Defined to tell the NAND controller that the NAND chip is using
1984 Not all NAND drivers use this symbol.
1985 Example of drivers that use it:
1986 - drivers/mtd/nand/raw/ndfc.c
1987 - drivers/mtd/nand/raw/mxc_nand.c
1989 - CONFIG_SYS_NDFC_EBC0_CFG
1990 Sets the EBC0_CFG register for the NDFC. If not defined
1991 a default value will be used.
1994 Get DDR timing information from an I2C EEPROM. Common
1995 with pluggable memory modules such as SODIMMs
1998 I2C address of the SPD EEPROM
2000 - CONFIG_SYS_SPD_BUS_NUM
2001 If SPD EEPROM is on an I2C bus other than the first
2002 one, specify here. Note that the value must resolve
2003 to something your driver can deal with.
2005 - CONFIG_FSL_DDR_INTERACTIVE
2006 Enable interactive DDR debugging. See doc/README.fsl-ddr.
2008 - CONFIG_FSL_DDR_SYNC_REFRESH
2009 Enable sync of refresh for multiple controllers.
2011 - CONFIG_FSL_DDR_BIST
2012 Enable built-in memory test for Freescale DDR controllers.
2015 Enable RMII mode for all FECs.
2016 Note that this is a global option, we can't
2017 have one FEC in standard MII mode and another in RMII mode.
2019 - CONFIG_CRC32_VERIFY
2020 Add a verify option to the crc32 command.
2023 => crc32 -v <address> <count> <crc32>
2025 Where address/count indicate a memory area
2026 and crc32 is the correct crc32 which the
2030 Add the "loopw" memory command. This only takes effect if
2031 the memory commands are activated globally (CONFIG_CMD_MEMORY).
2033 - CONFIG_CMD_MX_CYCLIC
2034 Add the "mdc" and "mwc" memory commands. These are cyclic
2039 This command will print 4 bytes (10,11,12,13) each 500 ms.
2041 => mwc.l 100 12345678 10
2042 This command will write 12345678 to address 100 all 10 ms.
2044 This only takes effect if the memory commands are activated
2045 globally (CONFIG_CMD_MEMORY).
2048 Set when the currently-running compilation is for an artifact
2049 that will end up in the SPL (as opposed to the TPL or U-Boot
2050 proper). Code that needs stage-specific behavior should check
2054 Set when the currently-running compilation is for an artifact
2055 that will end up in the TPL (as opposed to the SPL or U-Boot
2056 proper). Code that needs stage-specific behavior should check
2059 - CONFIG_ARCH_MAP_SYSMEM
2060 Generally U-Boot (and in particular the md command) uses
2061 effective address. It is therefore not necessary to regard
2062 U-Boot address as virtual addresses that need to be translated
2063 to physical addresses. However, sandbox requires this, since
2064 it maintains its own little RAM buffer which contains all
2065 addressable memory. This option causes some memory accesses
2066 to be mapped through map_sysmem() / unmap_sysmem().
2068 - CONFIG_X86_RESET_VECTOR
2069 If defined, the x86 reset vector code is included. This is not
2070 needed when U-Boot is running from Coreboot.
2072 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
2073 Option to disable subpage write in NAND driver
2074 driver that uses this:
2075 drivers/mtd/nand/raw/davinci_nand.c
2077 Freescale QE/FMAN Firmware Support:
2078 -----------------------------------
2080 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
2081 loading of "firmware", which is encoded in the QE firmware binary format.
2082 This firmware often needs to be loaded during U-Boot booting, so macros
2083 are used to identify the storage device (NOR flash, SPI, etc) and the address
2086 - CONFIG_SYS_FMAN_FW_ADDR
2087 The address in the storage device where the FMAN microcode is located. The
2088 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
2091 - CONFIG_SYS_QE_FW_ADDR
2092 The address in the storage device where the QE microcode is located. The
2093 meaning of this address depends on which CONFIG_SYS_QE_FMAN_FW_IN_xxx macro
2096 - CONFIG_SYS_QE_FMAN_FW_LENGTH
2097 The maximum possible size of the firmware. The firmware binary format
2098 has a field that specifies the actual size of the firmware, but it
2099 might not be possible to read any part of the firmware unless some
2100 local storage is allocated to hold the entire firmware first.
2102 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
2103 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
2104 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
2105 virtual address in NOR flash.
2107 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
2108 Specifies that QE/FMAN firmware is located in NAND flash.
2109 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
2111 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
2112 Specifies that QE/FMAN firmware is located on the primary SD/MMC
2113 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
2115 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
2116 Specifies that QE/FMAN firmware is located in the remote (master)
2117 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
2118 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
2119 window->master inbound window->master LAW->the ucode address in
2120 master's memory space.
2122 Freescale Layerscape Management Complex Firmware Support:
2123 ---------------------------------------------------------
2124 The Freescale Layerscape Management Complex (MC) supports the loading of
2126 This firmware often needs to be loaded during U-Boot booting, so macros
2127 are used to identify the storage device (NOR flash, SPI, etc) and the address
2130 - CONFIG_FSL_MC_ENET
2131 Enable the MC driver for Layerscape SoCs.
2133 Freescale Layerscape Debug Server Support:
2134 -------------------------------------------
2135 The Freescale Layerscape Debug Server Support supports the loading of
2136 "Debug Server firmware" and triggering SP boot-rom.
2137 This firmware often needs to be loaded during U-Boot booting.
2139 - CONFIG_SYS_MC_RSV_MEM_ALIGN
2140 Define alignment of reserved memory MC requires
2145 In order to achieve reproducible builds, timestamps used in the U-Boot build
2146 process have to be set to a fixed value.
2148 This is done using the SOURCE_DATE_EPOCH environment variable.
2149 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
2150 option for U-Boot or an environment variable in U-Boot.
2152 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
2154 Building the Software:
2155 ======================
2157 Building U-Boot has been tested in several native build environments
2158 and in many different cross environments. Of course we cannot support
2159 all possibly existing versions of cross development tools in all
2160 (potentially obsolete) versions. In case of tool chain problems we
2161 recommend to use the ELDK (see https://www.denx.de/wiki/DULG/ELDK)
2162 which is extensively used to build and test U-Boot.
2164 If you are not using a native environment, it is assumed that you
2165 have GNU cross compiling tools available in your path. In this case,
2166 you must set the environment variable CROSS_COMPILE in your shell.
2167 Note that no changes to the Makefile or any other source files are
2168 necessary. For example using the ELDK on a 4xx CPU, please enter:
2170 $ CROSS_COMPILE=ppc_4xx-
2171 $ export CROSS_COMPILE
2173 U-Boot is intended to be simple to build. After installing the
2174 sources you must configure U-Boot for one specific board type. This
2179 where "NAME_defconfig" is the name of one of the existing configu-
2180 rations; see configs/*_defconfig for supported names.
2182 Note: for some boards special configuration names may exist; check if
2183 additional information is available from the board vendor; for
2184 instance, the TQM823L systems are available without (standard)
2185 or with LCD support. You can select such additional "features"
2186 when choosing the configuration, i. e.
2188 make TQM823L_defconfig
2189 - will configure for a plain TQM823L, i. e. no LCD support
2191 make TQM823L_LCD_defconfig
2192 - will configure for a TQM823L with U-Boot console on LCD
2197 Finally, type "make all", and you should get some working U-Boot
2198 images ready for download to / installation on your system:
2200 - "u-boot.bin" is a raw binary image
2201 - "u-boot" is an image in ELF binary format
2202 - "u-boot.srec" is in Motorola S-Record format
2204 By default the build is performed locally and the objects are saved
2205 in the source directory. One of the two methods can be used to change
2206 this behavior and build U-Boot to some external directory:
2208 1. Add O= to the make command line invocations:
2210 make O=/tmp/build distclean
2211 make O=/tmp/build NAME_defconfig
2212 make O=/tmp/build all
2214 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
2216 export KBUILD_OUTPUT=/tmp/build
2221 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
2224 User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
2225 setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
2226 For example to treat all compiler warnings as errors:
2228 make KCFLAGS=-Werror
2230 Please be aware that the Makefiles assume you are using GNU make, so
2231 for instance on NetBSD you might need to use "gmake" instead of
2235 If the system board that you have is not listed, then you will need
2236 to port U-Boot to your hardware platform. To do this, follow these
2239 1. Create a new directory to hold your board specific code. Add any
2240 files you need. In your board directory, you will need at least
2241 the "Makefile" and a "<board>.c".
2242 2. Create a new configuration file "include/configs/<board>.h" for
2244 3. If you're porting U-Boot to a new CPU, then also create a new
2245 directory to hold your CPU specific code. Add any files you need.
2246 4. Run "make <board>_defconfig" with your new name.
2247 5. Type "make", and you should get a working "u-boot.srec" file
2248 to be installed on your target system.
2249 6. Debug and solve any problems that might arise.
2250 [Of course, this last step is much harder than it sounds.]
2253 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2254 ==============================================================
2256 If you have modified U-Boot sources (for instance added a new board
2257 or support for new devices, a new CPU, etc.) you are expected to
2258 provide feedback to the other developers. The feedback normally takes
2259 the form of a "patch", i.e. a context diff against a certain (latest
2260 official or latest in the git repository) version of U-Boot sources.
2262 But before you submit such a patch, please verify that your modifi-
2263 cation did not break existing code. At least make sure that *ALL* of
2264 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2265 just run the buildman script (tools/buildman/buildman), which will
2266 configure and build U-Boot for ALL supported system. Be warned, this
2267 will take a while. Please see the buildman README, or run 'buildman -H'
2271 See also "U-Boot Porting Guide" below.
2274 Monitor Commands - Overview:
2275 ============================
2277 go - start application at address 'addr'
2278 run - run commands in an environment variable
2279 bootm - boot application image from memory
2280 bootp - boot image via network using BootP/TFTP protocol
2281 bootz - boot zImage from memory
2282 tftpboot- boot image via network using TFTP protocol
2283 and env variables "ipaddr" and "serverip"
2284 (and eventually "gatewayip")
2285 tftpput - upload a file via network using TFTP protocol
2286 rarpboot- boot image via network using RARP/TFTP protocol
2287 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2288 loads - load S-Record file over serial line
2289 loadb - load binary file over serial line (kermit mode)
2290 loadm - load binary blob from source address to destination address
2292 mm - memory modify (auto-incrementing)
2293 nm - memory modify (constant address)
2294 mw - memory write (fill)
2297 cmp - memory compare
2298 crc32 - checksum calculation
2299 i2c - I2C sub-system
2300 sspi - SPI utility commands
2301 base - print or set address offset
2302 printenv- print environment variables
2303 pwm - control pwm channels
2304 setenv - set environment variables
2305 saveenv - save environment variables to persistent storage
2306 protect - enable or disable FLASH write protection
2307 erase - erase FLASH memory
2308 flinfo - print FLASH memory information
2309 nand - NAND memory operations (see doc/README.nand)
2310 bdinfo - print Board Info structure
2311 iminfo - print header information for application image
2312 coninfo - print console devices and informations
2313 ide - IDE sub-system
2314 loop - infinite loop on address range
2315 loopw - infinite write loop on address range
2316 mtest - simple RAM test
2317 icache - enable or disable instruction cache
2318 dcache - enable or disable data cache
2319 reset - Perform RESET of the CPU
2320 echo - echo args to console
2321 version - print monitor version
2322 help - print online help
2323 ? - alias for 'help'
2326 Monitor Commands - Detailed Description:
2327 ========================================
2331 For now: just type "help <command>".
2334 Note for Redundant Ethernet Interfaces:
2335 =======================================
2337 Some boards come with redundant Ethernet interfaces; U-Boot supports
2338 such configurations and is capable of automatic selection of a
2339 "working" interface when needed. MAC assignment works as follows:
2341 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2342 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2343 "eth1addr" (=>eth1), "eth2addr", ...
2345 If the network interface stores some valid MAC address (for instance
2346 in SROM), this is used as default address if there is NO correspon-
2347 ding setting in the environment; if the corresponding environment
2348 variable is set, this overrides the settings in the card; that means:
2350 o If the SROM has a valid MAC address, and there is no address in the
2351 environment, the SROM's address is used.
2353 o If there is no valid address in the SROM, and a definition in the
2354 environment exists, then the value from the environment variable is
2357 o If both the SROM and the environment contain a MAC address, and
2358 both addresses are the same, this MAC address is used.
2360 o If both the SROM and the environment contain a MAC address, and the
2361 addresses differ, the value from the environment is used and a
2364 o If neither SROM nor the environment contain a MAC address, an error
2365 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
2366 a random, locally-assigned MAC is used.
2368 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
2369 will be programmed into hardware as part of the initialization process. This
2370 may be skipped by setting the appropriate 'ethmacskip' environment variable.
2371 The naming convention is as follows:
2372 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
2377 U-Boot is capable of booting (and performing other auxiliary operations on)
2378 images in two formats:
2380 New uImage format (FIT)
2381 -----------------------
2383 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2384 to Flattened Device Tree). It allows the use of images with multiple
2385 components (several kernels, ramdisks, etc.), with contents protected by
2386 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2392 Old image format is based on binary files which can be basically anything,
2393 preceded by a special header; see the definitions in include/image.h for
2394 details; basically, the header defines the following image properties:
2396 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2397 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2398 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
2399 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, INTEGRITY).
2400 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2401 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2402 Currently supported: ARM, Intel x86, MIPS, Nios II, PowerPC).
2403 * Compression Type (uncompressed, gzip, bzip2)
2409 The header is marked by a special Magic Number, and both the header
2410 and the data portions of the image are secured against corruption by
2417 Although U-Boot should support any OS or standalone application
2418 easily, the main focus has always been on Linux during the design of
2421 U-Boot includes many features that so far have been part of some
2422 special "boot loader" code within the Linux kernel. Also, any
2423 "initrd" images to be used are no longer part of one big Linux image;
2424 instead, kernel and "initrd" are separate images. This implementation
2425 serves several purposes:
2427 - the same features can be used for other OS or standalone
2428 applications (for instance: using compressed images to reduce the
2429 Flash memory footprint)
2431 - it becomes much easier to port new Linux kernel versions because
2432 lots of low-level, hardware dependent stuff are done by U-Boot
2434 - the same Linux kernel image can now be used with different "initrd"
2435 images; of course this also means that different kernel images can
2436 be run with the same "initrd". This makes testing easier (you don't
2437 have to build a new "zImage.initrd" Linux image when you just
2438 change a file in your "initrd"). Also, a field-upgrade of the
2439 software is easier now.
2445 Porting Linux to U-Boot based systems:
2446 ---------------------------------------
2448 U-Boot cannot save you from doing all the necessary modifications to
2449 configure the Linux device drivers for use with your target hardware
2450 (no, we don't intend to provide a full virtual machine interface to
2453 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
2455 Just make sure your machine specific header file (for instance
2456 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2457 Information structure as we define in include/asm-<arch>/u-boot.h,
2458 and make sure that your definition of IMAP_ADDR uses the same value
2459 as your U-Boot configuration in CONFIG_SYS_IMMR.
2461 Note that U-Boot now has a driver model, a unified model for drivers.
2462 If you are adding a new driver, plumb it into driver model. If there
2463 is no uclass available, you are encouraged to create one. See
2467 Configuring the Linux kernel:
2468 -----------------------------
2470 No specific requirements for U-Boot. Make sure you have some root
2471 device (initial ramdisk, NFS) for your target system.
2474 Building a Linux Image:
2475 -----------------------
2477 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2478 not used. If you use recent kernel source, a new build target
2479 "uImage" will exist which automatically builds an image usable by
2480 U-Boot. Most older kernels also have support for a "pImage" target,
2481 which was introduced for our predecessor project PPCBoot and uses a
2482 100% compatible format.
2486 make TQM850L_defconfig
2491 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2492 encapsulate a compressed Linux kernel image with header information,
2493 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2495 * build a standard "vmlinux" kernel image (in ELF binary format):
2497 * convert the kernel into a raw binary image:
2499 ${CROSS_COMPILE}-objcopy -O binary \
2500 -R .note -R .comment \
2501 -S vmlinux linux.bin
2503 * compress the binary image:
2507 * package compressed binary image for U-Boot:
2509 mkimage -A ppc -O linux -T kernel -C gzip \
2510 -a 0 -e 0 -n "Linux Kernel Image" \
2511 -d linux.bin.gz uImage
2514 The "mkimage" tool can also be used to create ramdisk images for use
2515 with U-Boot, either separated from the Linux kernel image, or
2516 combined into one file. "mkimage" encapsulates the images with a 64
2517 byte header containing information about target architecture,
2518 operating system, image type, compression method, entry points, time
2519 stamp, CRC32 checksums, etc.
2521 "mkimage" can be called in two ways: to verify existing images and
2522 print the header information, or to build new images.
2524 In the first form (with "-l" option) mkimage lists the information
2525 contained in the header of an existing U-Boot image; this includes
2526 checksum verification:
2528 tools/mkimage -l image
2529 -l ==> list image header information
2531 The second form (with "-d" option) is used to build a U-Boot image
2532 from a "data file" which is used as image payload:
2534 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2535 -n name -d data_file image
2536 -A ==> set architecture to 'arch'
2537 -O ==> set operating system to 'os'
2538 -T ==> set image type to 'type'
2539 -C ==> set compression type 'comp'
2540 -a ==> set load address to 'addr' (hex)
2541 -e ==> set entry point to 'ep' (hex)
2542 -n ==> set image name to 'name'
2543 -d ==> use image data from 'datafile'
2545 Right now, all Linux kernels for PowerPC systems use the same load
2546 address (0x00000000), but the entry point address depends on the
2549 - 2.2.x kernels have the entry point at 0x0000000C,
2550 - 2.3.x and later kernels have the entry point at 0x00000000.
2552 So a typical call to build a U-Boot image would read:
2554 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2555 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2556 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
2557 > examples/uImage.TQM850L
2558 Image Name: 2.4.4 kernel for TQM850L
2559 Created: Wed Jul 19 02:34:59 2000
2560 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2561 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2562 Load Address: 0x00000000
2563 Entry Point: 0x00000000
2565 To verify the contents of the image (or check for corruption):
2567 -> tools/mkimage -l examples/uImage.TQM850L
2568 Image Name: 2.4.4 kernel for TQM850L
2569 Created: Wed Jul 19 02:34:59 2000
2570 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2571 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2572 Load Address: 0x00000000
2573 Entry Point: 0x00000000
2575 NOTE: for embedded systems where boot time is critical you can trade
2576 speed for memory and install an UNCOMPRESSED image instead: this
2577 needs more space in Flash, but boots much faster since it does not
2578 need to be uncompressed:
2580 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
2581 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2582 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2583 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
2584 > examples/uImage.TQM850L-uncompressed
2585 Image Name: 2.4.4 kernel for TQM850L
2586 Created: Wed Jul 19 02:34:59 2000
2587 Image Type: PowerPC Linux Kernel Image (uncompressed)
2588 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2589 Load Address: 0x00000000
2590 Entry Point: 0x00000000
2593 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2594 when your kernel is intended to use an initial ramdisk:
2596 -> tools/mkimage -n 'Simple Ramdisk Image' \
2597 > -A ppc -O linux -T ramdisk -C gzip \
2598 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2599 Image Name: Simple Ramdisk Image
2600 Created: Wed Jan 12 14:01:50 2000
2601 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2602 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2603 Load Address: 0x00000000
2604 Entry Point: 0x00000000
2606 The "dumpimage" tool can be used to disassemble or list the contents of images
2607 built by mkimage. See dumpimage's help output (-h) for details.
2609 Installing a Linux Image:
2610 -------------------------
2612 To downloading a U-Boot image over the serial (console) interface,
2613 you must convert the image to S-Record format:
2615 objcopy -I binary -O srec examples/image examples/image.srec
2617 The 'objcopy' does not understand the information in the U-Boot
2618 image header, so the resulting S-Record file will be relative to
2619 address 0x00000000. To load it to a given address, you need to
2620 specify the target address as 'offset' parameter with the 'loads'
2623 Example: install the image to address 0x40100000 (which on the
2624 TQM8xxL is in the first Flash bank):
2626 => erase 40100000 401FFFFF
2632 ## Ready for S-Record download ...
2633 ~>examples/image.srec
2634 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2636 15989 15990 15991 15992
2637 [file transfer complete]
2639 ## Start Addr = 0x00000000
2642 You can check the success of the download using the 'iminfo' command;
2643 this includes a checksum verification so you can be sure no data
2644 corruption happened:
2648 ## Checking Image at 40100000 ...
2649 Image Name: 2.2.13 for initrd on TQM850L
2650 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2651 Data Size: 335725 Bytes = 327 kB = 0 MB
2652 Load Address: 00000000
2653 Entry Point: 0000000c
2654 Verifying Checksum ... OK
2660 The "bootm" command is used to boot an application that is stored in
2661 memory (RAM or Flash). In case of a Linux kernel image, the contents
2662 of the "bootargs" environment variable is passed to the kernel as
2663 parameters. You can check and modify this variable using the
2664 "printenv" and "setenv" commands:
2667 => printenv bootargs
2668 bootargs=root=/dev/ram
2670 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2672 => printenv bootargs
2673 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2676 ## Booting Linux kernel at 40020000 ...
2677 Image Name: 2.2.13 for NFS on TQM850L
2678 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2679 Data Size: 381681 Bytes = 372 kB = 0 MB
2680 Load Address: 00000000
2681 Entry Point: 0000000c
2682 Verifying Checksum ... OK
2683 Uncompressing Kernel Image ... OK
2684 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
2685 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2686 time_init: decrementer frequency = 187500000/60
2687 Calibrating delay loop... 49.77 BogoMIPS
2688 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2691 If you want to boot a Linux kernel with initial RAM disk, you pass
2692 the memory addresses of both the kernel and the initrd image (PPBCOOT
2693 format!) to the "bootm" command:
2695 => imi 40100000 40200000
2697 ## Checking Image at 40100000 ...
2698 Image Name: 2.2.13 for initrd on TQM850L
2699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2700 Data Size: 335725 Bytes = 327 kB = 0 MB
2701 Load Address: 00000000
2702 Entry Point: 0000000c
2703 Verifying Checksum ... OK
2705 ## Checking Image at 40200000 ...
2706 Image Name: Simple Ramdisk Image
2707 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2708 Data Size: 566530 Bytes = 553 kB = 0 MB
2709 Load Address: 00000000
2710 Entry Point: 00000000
2711 Verifying Checksum ... OK
2713 => bootm 40100000 40200000
2714 ## Booting Linux kernel at 40100000 ...
2715 Image Name: 2.2.13 for initrd on TQM850L
2716 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2717 Data Size: 335725 Bytes = 327 kB = 0 MB
2718 Load Address: 00000000
2719 Entry Point: 0000000c
2720 Verifying Checksum ... OK
2721 Uncompressing Kernel Image ... OK
2722 ## Loading RAMDisk Image at 40200000 ...
2723 Image Name: Simple Ramdisk Image
2724 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2725 Data Size: 566530 Bytes = 553 kB = 0 MB
2726 Load Address: 00000000
2727 Entry Point: 00000000
2728 Verifying Checksum ... OK
2729 Loading Ramdisk ... OK
2730 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
2731 Boot arguments: root=/dev/ram
2732 time_init: decrementer frequency = 187500000/60
2733 Calibrating delay loop... 49.77 BogoMIPS
2735 RAMDISK: Compressed image found at block 0
2736 VFS: Mounted root (ext2 filesystem).
2740 Boot Linux and pass a flat device tree:
2743 First, U-Boot must be compiled with the appropriate defines. See the section
2744 titled "Linux Kernel Interface" above for a more in depth explanation. The
2745 following is an example of how to start a kernel and pass an updated
2751 oft=oftrees/mpc8540ads.dtb
2752 => tftp $oftaddr $oft
2753 Speed: 1000, full duplex
2755 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
2756 Filename 'oftrees/mpc8540ads.dtb'.
2757 Load address: 0x300000
2760 Bytes transferred = 4106 (100a hex)
2761 => tftp $loadaddr $bootfile
2762 Speed: 1000, full duplex
2764 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
2766 Load address: 0x200000
2767 Loading:############
2769 Bytes transferred = 1029407 (fb51f hex)
2774 => bootm $loadaddr - $oftaddr
2775 ## Booting image at 00200000 ...
2776 Image Name: Linux-2.6.17-dirty
2777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2778 Data Size: 1029343 Bytes = 1005.2 kB
2779 Load Address: 00000000
2780 Entry Point: 00000000
2781 Verifying Checksum ... OK
2782 Uncompressing Kernel Image ... OK
2783 Booting using flat device tree at 0x300000
2784 Using MPC85xx ADS machine description
2785 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
2789 More About U-Boot Image Types:
2790 ------------------------------
2792 U-Boot supports the following image types:
2794 "Standalone Programs" are directly runnable in the environment
2795 provided by U-Boot; it is expected that (if they behave
2796 well) you can continue to work in U-Boot after return from
2797 the Standalone Program.
2798 "OS Kernel Images" are usually images of some Embedded OS which
2799 will take over control completely. Usually these programs
2800 will install their own set of exception handlers, device
2801 drivers, set up the MMU, etc. - this means, that you cannot
2802 expect to re-enter U-Boot except by resetting the CPU.
2803 "RAMDisk Images" are more or less just data blocks, and their
2804 parameters (address, size) are passed to an OS kernel that is
2806 "Multi-File Images" contain several images, typically an OS
2807 (Linux) kernel image and one or more data images like
2808 RAMDisks. This construct is useful for instance when you want
2809 to boot over the network using BOOTP etc., where the boot
2810 server provides just a single image file, but you want to get
2811 for instance an OS kernel and a RAMDisk image.
2813 "Multi-File Images" start with a list of image sizes, each
2814 image size (in bytes) specified by an "uint32_t" in network
2815 byte order. This list is terminated by an "(uint32_t)0".
2816 Immediately after the terminating 0 follow the images, one by
2817 one, all aligned on "uint32_t" boundaries (size rounded up to
2818 a multiple of 4 bytes).
2820 "Firmware Images" are binary images containing firmware (like
2821 U-Boot or FPGA images) which usually will be programmed to
2824 "Script files" are command sequences that will be executed by
2825 U-Boot's command interpreter; this feature is especially
2826 useful when you configure U-Boot to use a real shell (hush)
2827 as command interpreter.
2829 Booting the Linux zImage:
2830 -------------------------
2832 On some platforms, it's possible to boot Linux zImage. This is done
2833 using the "bootz" command. The syntax of "bootz" command is the same
2834 as the syntax of "bootm" command.
2836 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
2837 kernel with raw initrd images. The syntax is slightly different, the
2838 address of the initrd must be augmented by it's size, in the following
2839 format: "<initrd addres>:<initrd size>".
2845 One of the features of U-Boot is that you can dynamically load and
2846 run "standalone" applications, which can use some resources of
2847 U-Boot like console I/O functions or interrupt services.
2849 Two simple examples are included with the sources:
2854 'examples/hello_world.c' contains a small "Hello World" Demo
2855 application; it is automatically compiled when you build U-Boot.
2856 It's configured to run at address 0x00040004, so you can play with it
2860 ## Ready for S-Record download ...
2861 ~>examples/hello_world.srec
2862 1 2 3 4 5 6 7 8 9 10 11 ...
2863 [file transfer complete]
2865 ## Start Addr = 0x00040004
2867 => go 40004 Hello World! This is a test.
2868 ## Starting application at 0x00040004 ...
2879 Hit any key to exit ...
2881 ## Application terminated, rc = 0x0
2883 Another example, which demonstrates how to register a CPM interrupt
2884 handler with the U-Boot code, can be found in 'examples/timer.c'.
2885 Here, a CPM timer is set up to generate an interrupt every second.
2886 The interrupt service routine is trivial, just printing a '.'
2887 character, but this is just a demo program. The application can be
2888 controlled by the following keys:
2890 ? - print current values og the CPM Timer registers
2891 b - enable interrupts and start timer
2892 e - stop timer and disable interrupts
2893 q - quit application
2896 ## Ready for S-Record download ...
2897 ~>examples/timer.srec
2898 1 2 3 4 5 6 7 8 9 10 11 ...
2899 [file transfer complete]
2901 ## Start Addr = 0x00040004
2904 ## Starting application at 0x00040004 ...
2907 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2910 [q, b, e, ?] Set interval 1000000 us
2913 [q, b, e, ?] ........
2914 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2917 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2920 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2923 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2925 [q, b, e, ?] ...Stopping timer
2927 [q, b, e, ?] ## Application terminated, rc = 0x0
2933 Over time, many people have reported problems when trying to use the
2934 "minicom" terminal emulation program for serial download. I (wd)
2935 consider minicom to be broken, and recommend not to use it. Under
2936 Unix, I recommend to use C-Kermit for general purpose use (and
2937 especially for kermit binary protocol download ("loadb" command), and
2938 use "cu" for S-Record download ("loads" command). See
2939 https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
2940 for help with kermit.
2943 Nevertheless, if you absolutely want to use it try adding this
2944 configuration to your "File transfer protocols" section:
2946 Name Program Name U/D FullScr IO-Red. Multi
2947 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2948 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2954 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2955 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2957 Building requires a cross environment; it is known to work on
2958 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2959 need gmake since the Makefiles are not compatible with BSD make).
2960 Note that the cross-powerpc package does not install include files;
2961 attempting to build U-Boot will fail because <machine/ansi.h> is
2962 missing. This file has to be installed and patched manually:
2964 # cd /usr/pkg/cross/powerpc-netbsd/include
2966 # ln -s powerpc machine
2967 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2968 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2970 Native builds *don't* work due to incompatibilities between native
2971 and U-Boot include files.
2973 Booting assumes that (the first part of) the image booted is a
2974 stage-2 loader which in turn loads and then invokes the kernel
2975 proper. Loader sources will eventually appear in the NetBSD source
2976 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2977 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
2980 Implementation Internals:
2981 =========================
2983 The following is not intended to be a complete description of every
2984 implementation detail. However, it should help to understand the
2985 inner workings of U-Boot and make it easier to port it to custom
2989 Initial Stack, Global Data:
2990 ---------------------------
2992 The implementation of U-Boot is complicated by the fact that U-Boot
2993 starts running out of ROM (flash memory), usually without access to
2994 system RAM (because the memory controller is not initialized yet).
2995 This means that we don't have writable Data or BSS segments, and BSS
2996 is not initialized as zero. To be able to get a C environment working
2997 at all, we have to allocate at least a minimal stack. Implementation
2998 options for this are defined and restricted by the CPU used: Some CPU
2999 models provide on-chip memory (like the IMMR area on MPC8xx and
3000 MPC826x processors), on others (parts of) the data cache can be
3001 locked as (mis-) used as memory, etc.
3003 Chris Hallinan posted a good summary of these issues to the
3004 U-Boot mailing list:
3006 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3007 From: "Chris Hallinan" <clh@net1plus.com>
3008 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3011 Correct me if I'm wrong, folks, but the way I understand it
3012 is this: Using DCACHE as initial RAM for Stack, etc, does not
3013 require any physical RAM backing up the cache. The cleverness
3014 is that the cache is being used as a temporary supply of
3015 necessary storage before the SDRAM controller is setup. It's
3016 beyond the scope of this list to explain the details, but you
3017 can see how this works by studying the cache architecture and
3018 operation in the architecture and processor-specific manuals.
3020 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3021 is another option for the system designer to use as an
3022 initial stack/RAM area prior to SDRAM being available. Either
3023 option should work for you. Using CS 4 should be fine if your
3024 board designers haven't used it for something that would
3025 cause you grief during the initial boot! It is frequently not
3028 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3029 with your processor/board/system design. The default value
3030 you will find in any recent u-boot distribution in
3031 walnut.h should work for you. I'd set it to a value larger
3032 than your SDRAM module. If you have a 64MB SDRAM module, set
3033 it above 400_0000. Just make sure your board has no resources
3034 that are supposed to respond to that address! That code in
3035 start.S has been around a while and should work as is when
3036 you get the config right.
3041 It is essential to remember this, since it has some impact on the C
3042 code for the initialization procedures:
3044 * Initialized global data (data segment) is read-only. Do not attempt
3047 * Do not use any uninitialized global data (or implicitly initialized
3048 as zero data - BSS segment) at all - this is undefined, initiali-
3049 zation is performed later (when relocating to RAM).
3051 * Stack space is very limited. Avoid big data buffers or things like
3054 Having only the stack as writable memory limits means we cannot use
3055 normal global data to share information between the code. But it
3056 turned out that the implementation of U-Boot can be greatly
3057 simplified by making a global data structure (gd_t) available to all
3058 functions. We could pass a pointer to this data as argument to _all_
3059 functions, but this would bloat the code. Instead we use a feature of
3060 the GCC compiler (Global Register Variables) to share the data: we
3061 place a pointer (gd) to the global data into a register which we
3062 reserve for this purpose.
3064 When choosing a register for such a purpose we are restricted by the
3065 relevant (E)ABI specifications for the current architecture, and by
3066 GCC's implementation.
3068 For PowerPC, the following registers have specific use:
3070 R2: reserved for system use
3071 R3-R4: parameter passing and return values
3072 R5-R10: parameter passing
3073 R13: small data area pointer
3077 (U-Boot also uses R12 as internal GOT pointer. r12
3078 is a volatile register so r12 needs to be reset when
3079 going back and forth between asm and C)
3081 ==> U-Boot will use R2 to hold a pointer to the global data
3083 Note: on PPC, we could use a static initializer (since the
3084 address of the global data structure is known at compile time),
3085 but it turned out that reserving a register results in somewhat
3086 smaller code - although the code savings are not that big (on
3087 average for all boards 752 bytes for the whole U-Boot image,
3088 624 text + 127 data).
3090 On ARM, the following registers are used:
3092 R0: function argument word/integer result
3093 R1-R3: function argument word
3094 R9: platform specific
3095 R10: stack limit (used only if stack checking is enabled)
3096 R11: argument (frame) pointer
3097 R12: temporary workspace
3100 R15: program counter
3102 ==> U-Boot will use R9 to hold a pointer to the global data
3104 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
3106 On Nios II, the ABI is documented here:
3107 https://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
3109 ==> U-Boot will use gp to hold a pointer to the global data
3111 Note: on Nios II, we give "-G0" option to gcc and don't use gp
3112 to access small data sections, so gp is free.
3114 On RISC-V, the following registers are used:
3116 x0: hard-wired zero (zero)
3117 x1: return address (ra)
3118 x2: stack pointer (sp)
3119 x3: global pointer (gp)
3120 x4: thread pointer (tp)
3121 x5: link register (t0)
3122 x8: frame pointer (fp)
3123 x10-x11: arguments/return values (a0-1)
3124 x12-x17: arguments (a2-7)
3125 x28-31: temporaries (t3-6)
3126 pc: program counter (pc)
3128 ==> U-Boot will use gp to hold a pointer to the global data
3133 U-Boot runs in system state and uses physical addresses, i.e. the
3134 MMU is not used either for address mapping nor for memory protection.
3136 The available memory is mapped to fixed addresses using the memory
3137 controller. In this process, a contiguous block is formed for each
3138 memory type (Flash, SDRAM, SRAM), even when it consists of several
3139 physical memory banks.
3141 U-Boot is installed in the first 128 kB of the first Flash bank (on
3142 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3143 booting and sizing and initializing DRAM, the code relocates itself
3144 to the upper end of DRAM. Immediately below the U-Boot code some
3145 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3146 configuration setting]. Below that, a structure with global Board
3147 Info data is placed, followed by the stack (growing downward).
3149 Additionally, some exception handler code is copied to the low 8 kB
3150 of DRAM (0x00000000 ... 0x00001FFF).
3152 So a typical memory configuration with 16 MB of DRAM could look like
3155 0x0000 0000 Exception Vector code
3158 0x0000 2000 Free for Application Use
3164 0x00FB FF20 Monitor Stack (Growing downward)
3165 0x00FB FFAC Board Info Data and permanent copy of global data
3166 0x00FC 0000 Malloc Arena
3169 0x00FE 0000 RAM Copy of Monitor Code
3170 ... eventually: LCD or video framebuffer
3171 ... eventually: pRAM (Protected RAM - unchanged by reset)
3172 0x00FF FFFF [End of RAM]
3175 System Initialization:
3176 ----------------------
3178 In the reset configuration, U-Boot starts at the reset entry point
3179 (on most PowerPC systems at address 0x00000100). Because of the reset
3180 configuration for CS0# this is a mirror of the on board Flash memory.
3181 To be able to re-map memory U-Boot then jumps to its link address.
3182 To be able to implement the initialization code in C, a (small!)
3183 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3184 which provide such a feature like), or in a locked part of the data
3185 cache. After that, U-Boot initializes the CPU core, the caches and
3188 Next, all (potentially) available memory banks are mapped using a
3189 preliminary mapping. For example, we put them on 512 MB boundaries
3190 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3191 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3192 programmed for SDRAM access. Using the temporary configuration, a
3193 simple memory test is run that determines the size of the SDRAM
3196 When there is more than one SDRAM bank, and the banks are of
3197 different size, the largest is mapped first. For equal size, the first
3198 bank (CS2#) is mapped first. The first mapping is always for address
3199 0x00000000, with any additional banks following immediately to create
3200 contiguous memory starting from 0.
3202 Then, the monitor installs itself at the upper end of the SDRAM area
3203 and allocates memory for use by malloc() and for the global Board
3204 Info data; also, the exception vector code is copied to the low RAM
3205 pages, and the final stack is set up.
3207 Only after this relocation will you have a "normal" C environment;
3208 until that you are restricted in several ways, mostly because you are
3209 running from ROM, and because the code will have to be relocated to a
3213 U-Boot Porting Guide:
3214 ----------------------
3216 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3220 int main(int argc, char *argv[])
3222 sighandler_t no_more_time;
3224 signal(SIGALRM, no_more_time);
3225 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
3227 if (available_money > available_manpower) {
3228 Pay consultant to port U-Boot;
3232 Download latest U-Boot source;
3234 Subscribe to u-boot mailing list;
3237 email("Hi, I am new to U-Boot, how do I get started?");
3240 Read the README file in the top level directory;
3241 Read https://www.denx.de/wiki/bin/view/DULG/Manual;
3242 Read applicable doc/README.*;
3243 Read the source, Luke;
3244 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
3247 if (available_money > toLocalCurrency ($2500))
3250 Add a lot of aggravation and time;
3252 if (a similar board exists) { /* hopefully... */
3253 cp -a board/<similar> board/<myboard>
3254 cp include/configs/<similar>.h include/configs/<myboard>.h
3256 Create your own board support subdirectory;
3257 Create your own board include/configs/<myboard>.h file;
3259 Edit new board/<myboard> files
3260 Edit new include/configs/<myboard>.h
3265 Add / modify source code;
3269 email("Hi, I am having problems...");
3271 Send patch file to the U-Boot email list;
3272 if (reasonable critiques)
3273 Incorporate improvements from email list code review;
3275 Defend code as written;
3281 void no_more_time (int sig)
3290 All contributions to U-Boot should conform to the Linux kernel
3291 coding style; see the kernel coding style guide at
3292 https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
3293 script "scripts/Lindent" in your Linux kernel source directory.
3295 Source files originating from a different project (for example the
3296 MTD subsystem) are generally exempt from these guidelines and are not
3297 reformatted to ease subsequent migration to newer versions of those
3300 Please note that U-Boot is implemented in C (and to some small parts in
3301 Assembler); no C++ is used, so please do not use C++ style comments (//)
3304 Please also stick to the following formatting rules:
3305 - remove any trailing white space
3306 - use TAB characters for indentation and vertical alignment, not spaces
3307 - make sure NOT to use DOS '\r\n' line feeds
3308 - do not add more than 2 consecutive empty lines to source files
3309 - do not add trailing empty lines to source files
3311 Submissions which do not conform to the standards may be returned
3312 with a request to reformat the changes.
3318 Since the number of patches for U-Boot is growing, we need to
3319 establish some rules. Submissions which do not conform to these rules
3320 may be rejected, even when they contain important and valuable stuff.
3322 Please see https://www.denx.de/wiki/U-Boot/Patches for details.
3324 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
3325 see https://lists.denx.de/listinfo/u-boot
3327 When you send a patch, please include the following information with
3330 * For bug fixes: a description of the bug and how your patch fixes
3331 this bug. Please try to include a way of demonstrating that the
3332 patch actually fixes something.
3334 * For new features: a description of the feature and your
3337 * For major contributions, add a MAINTAINERS file with your
3338 information and associated file and directory references.
3340 * When you add support for a new board, don't forget to add a
3341 maintainer e-mail address to the boards.cfg file, too.
3343 * If your patch adds new configuration options, don't forget to
3344 document these in the README file.
3346 * The patch itself. If you are using git (which is *strongly*
3347 recommended) you can easily generate the patch using the
3348 "git format-patch". If you then use "git send-email" to send it to
3349 the U-Boot mailing list, you will avoid most of the common problems
3350 with some other mail clients.
3352 If you cannot use git, use "diff -purN OLD NEW". If your version of
3353 diff does not support these options, then get the latest version of
3356 The current directory when running this command shall be the parent
3357 directory of the U-Boot source tree (i. e. please make sure that
3358 your patch includes sufficient directory information for the
3361 We prefer patches as plain text. MIME attachments are discouraged,
3362 and compressed attachments must not be used.
3364 * If one logical set of modifications affects or creates several
3365 files, all these changes shall be submitted in a SINGLE patch file.
3367 * Changesets that contain different, unrelated modifications shall be
3368 submitted as SEPARATE patches, one patch per changeset.
3373 * Before sending the patch, run the buildman script on your patched
3374 source tree and make sure that no errors or warnings are reported
3375 for any of the boards.
3377 * Keep your modifications to the necessary minimum: A patch
3378 containing several unrelated changes or arbitrary reformats will be
3379 returned with a request to re-formatting / split it.
3381 * If you modify existing code, make sure that your new code does not
3382 add to the memory footprint of the code ;-) Small is beautiful!
3383 When adding new features, these should compile conditionally only
3384 (using #ifdef), and the resulting code with the new feature
3385 disabled must not need more memory than the old code without your
3388 * Remember that there is a size limit of 100 kB per message on the
3389 u-boot mailing list. Bigger patches will be moderated. If they are
3390 reasonable and not too big, they will be acknowledged. But patches
3391 bigger than the size limit should be avoided.