2 # For a description of the syntax of this configuration file,
3 # see the file Documentation/kbuild/kconfig-language.txt in the
4 # Linux kernel source tree.
6 mainmenu "U-Boot $(UBOOTVERSION) Configuration"
8 comment "Compiler: $(CC_VERSION_TEXT)"
10 source "scripts/Kconfig.include"
12 # Allow defaults in arch-specific code to override any given here
20 This option cannot be enabled. It is used as dependency
21 for broken and incomplete features.
26 This option cannot be enabled. It it used as a dependency for
27 code that relies on deprecated features that will be removed and
28 the conversion deadline has passed.
31 string "Local version - append to U-Boot release"
33 Append an extra string to the end of your U-Boot version.
34 This will show up in your boot log, for example.
35 The string you set here will be appended after the contents of
36 any files with a filename matching localversion* in your
37 object and source tree, in that order. Your total string can
38 be a maximum of 64 characters.
40 config LOCALVERSION_AUTO
41 bool "Automatically append version information to the version string"
44 This will try to automatically determine if the current tree is a
45 release tree by looking for Git tags that belong to the current
48 A string of the format -gxxxxxxxx will be added to the localversion
49 if a Git-based tree is found. The string generated by this will be
50 appended after any matching localversion* files, and after the value
51 set in CONFIG_LOCALVERSION.
53 (The actual string used here is the first eight characters produced
54 by running the command:
56 $ git rev-parse --verify HEAD
58 which is done within the script "scripts/setlocalversion".)
60 config CC_OPTIMIZE_FOR_SIZE
61 bool "Optimize for size"
64 Enabling this option will pass "-Os" instead of "-O2" to gcc
65 resulting in a smaller U-Boot image.
67 This option is enabled by default for U-Boot.
69 config OPTIMIZE_INLINING
70 bool "Allow compiler to uninline functions marked 'inline' in full U-Boot"
73 This option determines if U-Boot forces gcc to inline the functions
74 developers have marked 'inline'. Doing so takes away freedom from gcc to
75 do what it thinks is best, which is desirable in some cases for size
78 config SPL_OPTIMIZE_INLINING
79 bool "Allow compiler to uninline functions marked 'inline' in SPL"
83 This option determines if U-Boot forces gcc to inline the functions
84 developers have marked 'inline'. Doing so takes away freedom from gcc to
85 do what it thinks is best, which is desirable in some cases for size
88 config TPL_OPTIMIZE_INLINING
89 bool "Allow compiler to uninline functions marked 'inline' in TPL"
93 This option determines if U-Boot forces gcc to inline the functions
94 developers have marked 'inline'. Doing so takes away freedom from gcc to
95 do what it thinks is best, which is desirable in some cases for size
99 bool "Enable code coverage analysis"
102 Enabling this option will pass "--coverage" to gcc to compile
103 and link code instrumented for coverage analysis.
105 config CC_HAS_ASM_INLINE
106 def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
109 bool "Select U-Boot be run as a bootloader for XEN Virtual Machine"
111 Enabling this option will make U-Boot be run as a bootloader
112 for XEN [1] Virtual Machine.
114 Xen is a virtual machine monitor (VMM) or a type-1 hypervisor with support
115 for para-virtualization. Xen can organize the safe execution of several
116 virtual machines on the same physical system with performance close to
117 native. It is used as the basis for a number of different commercial and
118 open source applications, such as: server virtualization, Infrastructure
119 as a Service (IaaS), desktop virtualization, security applications,
120 embedded and hardware appliances.
121 Xen has a special VM called Domain-0 that runs the Dom0 kernel and allows
122 Xen to use the device drivers for the Domain-0 kernel by default.
124 [1] - https://xenproject.org/
126 config DISTRO_DEFAULTS
127 bool "Select defaults suitable for booting general purpose Linux distributions"
129 select CMDLINE_EDITING
130 select CMD_BOOTI if ARM64
131 select CMD_BOOTZ if ARM && !ARM64
132 select CMD_DHCP if CMD_NET
133 select CMD_ENV_EXISTS
137 select CMD_FS_GENERIC
138 select CMD_PART if PARTITIONS
139 select CMD_PING if CMD_NET
140 select CMD_PXE if NET
142 select ENV_VARS_UBOOT_CONFIG
144 select SUPPORT_RAW_INITRD
148 imply USE_BOOTCOMMAND
150 Select this to enable various options and commands which are suitable
151 for building u-boot for booting general purpose Linux distributions.
153 config ENV_VARS_UBOOT_CONFIG
154 bool "Add arch, board, vendor and soc variables to default environment"
156 Define this in order to add variables describing the
157 U-Boot build configuration to the default environment.
158 These will be named arch, cpu, board, vendor, and soc.
159 Enabling this option will cause the following to be defined:
167 int "Number of DRAM banks"
168 default 1 if ARCH_SUNXI || ARCH_OWL
171 This defines the number of DRAM banks.
173 config SYS_BOOT_GET_CMDLINE
174 bool "Enable kernel command line setup"
176 Enables allocating and saving kernel cmdline in space between
177 "bootm_low" and "bootm_low" + BOOTMAPSZ.
179 config SYS_BOOT_GET_KBD
180 bool "Enable kernel board information setup"
182 Enables allocating and saving a kernel copy of the bd_info in
183 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
186 bool "Enable malloc() pool before relocation"
190 Before relocation, memory is very limited on many platforms. Still,
191 we can provide a small malloc() pool if needed. Driver model in
192 particular needs this to operate, so that it can allocate the
193 initial serial device and any others that are needed.
195 config SYS_MALLOC_F_LEN
196 hex "Size of malloc() pool before relocation"
197 depends on SYS_MALLOC_F
198 default 0x1000 if AM33XX
199 default 0x2800 if SANDBOX
200 default 0x2000 if (ARCH_IMX8 || ARCH_IMX8M || ARCH_MX7 || \
201 ARCH_MX7ULP || ARCH_MX6 || ARCH_MX5 || \
202 ARCH_LS1012A || ARCH_LS1021A || ARCH_LS1043A || \
203 ARCH_LS1046A || ARCH_QEMU)
206 Before relocation, memory is very limited on many platforms. Still,
207 we can provide a small malloc() pool if needed. Driver model in
208 particular needs this to operate, so that it can allocate the
209 initial serial device and any others that are needed.
211 config SYS_MALLOC_LEN
212 hex "Define memory for Dynamic allocation"
213 depends on ARCH_ZYNQ || ARCH_VERSAL || ARCH_STM32MP || ARCH_ROCKCHIP
214 default 0x2000000 if ARCH_ROCKCHIP
216 This defines memory to be allocated for Dynamic allocation
217 TODO: Use for other architectures
219 config SPL_SYS_MALLOC_F_LEN
220 hex "Size of malloc() pool in SPL before relocation"
221 depends on SYS_MALLOC_F && SPL
222 default 0x2800 if RCAR_GEN3
223 default SYS_MALLOC_F_LEN
225 Before relocation, memory is very limited on many platforms. Still,
226 we can provide a small malloc() pool if needed. Driver model in
227 particular needs this to operate, so that it can allocate the
228 initial serial device and any others that are needed.
230 config TPL_SYS_MALLOC_F_LEN
231 hex "Size of malloc() pool in TPL before relocation"
232 depends on SYS_MALLOC_F && TPL
233 default SYS_MALLOC_F_LEN
235 Before relocation, memory is very limited on many platforms. Still,
236 we can provide a small malloc() pool if needed. Driver model in
237 particular needs this to operate, so that it can allocate the
238 initial serial device and any others that are needed.
241 bool "Configure standard U-Boot features (expert users)"
244 This option allows certain base U-Boot options and settings
245 to be disabled or tweaked. This is for specialized
246 environments which can tolerate a "non-standard" U-Boot.
247 Use this only if you really know what you are doing.
250 config SYS_MALLOC_CLEAR_ON_INIT
251 bool "Init with zeros the memory reserved for malloc (slow)"
254 This setting is enabled by default. The reserved malloc
255 memory is initialized with zeros, so first malloc calls
256 will return the pointer to the zeroed memory. But this
259 It is recommended to disable it, when CONFIG_SYS_MALLOC_LEN
260 value, has more than few MiB, e.g. when uses bzip2 or bmp logo.
261 Then the boot time can be significantly reduced.
263 When disabling this, please check if malloc calls, maybe
264 should be replaced by calloc - if one expects zeroed memory.
266 config SYS_MALLOC_DEFAULT_TO_INIT
267 bool "Default malloc to init while reserving the memory for it"
270 It may happen that one needs to move the dynamic allocation
271 from one to another memory range, eg. when moving the malloc
272 from the limited static to a potentially large dynamic (DDR)
275 If so then on top of setting the updated memory aside one
276 needs to bring the malloc init.
278 If such a scenario is sought choose yes.
281 bool "Enable debug information for tools"
283 Enable generation of debug information for tools such as mkimage.
284 This can be used for debugging purposes. With debug information
285 it is possible to set breakpoints on particular lines, single-step
286 debug through the source code, etc.
291 bool "64bit physical address support"
293 Say Y here to support 64bit physical memory address.
294 This can be used not only for 64bit SoCs, but also for
295 large physical address extension on 32bit SoCs.
301 Enables building of a u-boot.rom target. This collects U-Boot and
302 any necessary binary blobs.
304 config ROM_NEEDS_BLOBS
308 Enable this if building the u-boot.rom target needs binary blobs, and
309 so cannot be done normally. In this case, U-Boot will only build the
310 ROM if the required blobs exist. If not, you will see an warning like:
312 Image 'main-section' is missing external blobs and is non-functional:
313 intel-descriptor intel-me intel-refcode intel-vga intel-mrc
316 bool "Build U-Boot as BIOS replacement"
318 default y if !ROM_NEEDS_BLOBS
320 This option allows to build a ROM version of U-Boot.
321 The build process generally requires several binary blobs
322 which are not shipped in the U-Boot source tree.
323 Please, see doc/arch/x86.rst for details.
326 string "SPL image used in the combined SPL+U-Boot image"
327 default "spl/boot.bin" if ARCH_AT91 && SPL_NAND_SUPPORT
328 default "spl/u-boot-spl.bin"
331 Select the SPL build target that shall be generated by the SPL
332 build process (default spl/u-boot-spl.bin). This image will be
333 used to generate a combined image with SPL and main U-Boot
334 proper as one single image.
337 string "Build target special images"
338 default "u-boot-with-spl.sfp" if TARGET_SOCFPGA_ARRIA10
339 default "u-boot-with-spl.sfp" if TARGET_SOCFPGA_GEN5
340 default "u-boot-spl.kwb" if ARCH_MVEBU && SPL
341 default "u-boot-elf.srec" if RCAR_GEN3
342 default "u-boot.itb" if !BINMAN && SPL_LOAD_FIT && (ARCH_ROCKCHIP || \
343 ARCH_SUNXI || RISCV || ARCH_ZYNQMP)
344 default "u-boot.kwb" if ARCH_KIRKWOOD
345 default "u-boot-with-spl.bin" if ARCH_AT91 && SPL_NAND_SUPPORT
346 default "u-boot-with-spl.imx" if ARCH_MX6 && SPL
348 Some SoCs need special image types (e.g. U-Boot binary
349 with a special header) as build targets. By defining
350 CONFIG_BUILD_TARGET in the SoC / board header, this
351 special image will be automatically built upon calling
354 config SYS_CUSTOM_LDSCRIPT
355 bool "Use a custom location for the U-Boot linker script"
357 Normally when linking U-Boot we will look in the board directory,
358 the CPU directory and finally the "cpu" directory of the architecture
359 for the ile "u-boot.lds" and use that as our linker. However, in
360 some cases we need to provide a different linker script. To do so,
361 enable this option and then provide the location under
365 depends on SYS_CUSTOM_LDSCRIPT
366 string "Custom ldscript location"
368 Path within the source tree to the linker script to use for the
371 config ERR_PTR_OFFSET
375 Some U-Boot pointers have redundant information, so we can use a
376 scheme where we can return either an error code or a pointer with the
377 same return value. The default implementation just casts the pointer
378 to a number, however, this may fail on platforms where the end of the
379 address range is used for valid pointers (e.g. 0xffffff00 is a valid
380 heap pointer in socfpga SPL).
381 For such platforms, this value provides an upper range of those error
382 pointer values - up to 'MAX_ERRNO' bytes below this value must be
383 unused/invalid addresses.
385 config PLATFORM_ELFENTRY
387 default "__start" if MIPS
391 hex "Define max stack size that can be used by U-Boot"
392 default 0x4000000 if ARCH_VERSAL || ARCH_ZYNQMP
393 default 0x200000 if MICROBLAZE
396 Define Max stack size that can be used by U-Boot. This value is used
397 by the UEFI sub-system. On some boards initrd_high is calculated as
398 base stack pointer minus this stack size.
402 default y if TARGET_PIC32MZDASK
403 default y if TARGET_DEVKIT8000
404 default y if TARGET_TRICORDER
407 Enable this to allow support for the on board SRAM.
408 SRAM base address is controlled by CONFIG_SYS_SRAM_BASE.
409 SRAM size is controlled by CONFIG_SYS_SRAM_SIZE.
413 default 0x80000000 if TARGET_PIC32MZDASK
414 default 0x40200000 if TARGET_DEVKIT8000
415 default 0x40200000 if TARGET_TRICORDER
420 default 0x00080000 if TARGET_PIC32MZDASK
421 default 0x10000 if TARGET_DEVKIT8000
422 default 0x10000 if TARGET_TRICORDER
425 endmenu # General setup
429 config ANDROID_BOOT_IMAGE
430 bool "Enable support for Android Boot Images"
431 default y if FASTBOOT
433 This enables support for booting images which use the Android
437 bool "Support Flattened Image Tree"
441 This option allows you to boot the new uImage structure,
442 Flattened Image Tree. FIT is formally a FDT, which can include
443 images of various types (kernel, FDT blob, ramdisk, etc.)
444 in a single blob. To boot this new uImage structure,
445 pass the address of the blob to the "bootm" command.
446 FIT is very flexible, supporting compression, multiple images,
447 multiple configurations, verification through hashing and also
448 verified boot (secure boot using RSA).
452 config FIT_EXTERNAL_OFFSET
453 hex "FIT external data offset"
456 This specifies a data offset in fit image.
457 The offset is from data payload offset to the beginning of
458 fit image header. When specifies a offset, specific data
459 could be put in the hole between data payload and fit image
460 header, such as CSF data on i.MX platform.
462 config FIT_ENABLE_SHA256_SUPPORT
463 bool "Support SHA256 checksum of FIT image contents"
467 Enable this to support SHA256 checksum of FIT image contents. A
468 SHA256 checksum is a 256-bit (32-byte) hash value used to check that
469 the image contents have not been corrupted.
471 config FIT_ENABLE_SHA384_SUPPORT
472 bool "Support SHA384 checksum of FIT image contents"
476 Enable this to support SHA384 checksum of FIT image contents. A
477 SHA384 checksum is a 384-bit (48-byte) hash value used to check that
478 the image contents have not been corrupted. Use this for the highest
481 config FIT_ENABLE_SHA512_SUPPORT
482 bool "Support SHA512 checksum of FIT image contents"
486 Enable this to support SHA512 checksum of FIT image contents. A
487 SHA512 checksum is a 512-bit (64-byte) hash value used to check that
488 the image contents have not been corrupted.
491 bool "Enable signature verification of FIT uImages"
496 select IMAGE_SIGN_INFO
498 This option enables signature verification of FIT uImages,
499 using a hash signed and verified using RSA. If
500 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
501 hashing is available using hardware, then the RSA library will use
502 it. See doc/uImage.FIT/signature.txt for more details.
504 WARNING: When relying on signed FIT images with a required signature
505 check the legacy image format is disabled by default, so that
506 unsigned images cannot be loaded. If a board needs the legacy image
507 format support in this case, enable it using
508 CONFIG_LEGACY_IMAGE_FORMAT.
510 config FIT_SIGNATURE_MAX_SIZE
511 hex "Max size of signed FIT structures"
512 depends on FIT_SIGNATURE
515 This option sets a max size in bytes for verified FIT uImages.
516 A sane value of 256MB protects corrupted DTB structures from overlapping
517 device memory. Assure this size does not extend past expected storage
520 config FIT_ENABLE_RSASSA_PSS_SUPPORT
521 bool "Support rsassa-pss signature scheme of FIT image contents"
522 depends on FIT_SIGNATURE
525 Enable this to support the pss padding algorithm as described
526 in the rfc8017 (https://tools.ietf.org/html/rfc8017).
529 bool "Enable ciphering data in a FIT uImages"
533 Enable the feature of data ciphering/unciphering in the tool mkimage
534 and in the u-boot support of the FIT image.
537 bool "Show verbose messages when FIT images fail"
539 Generally a system will have valid FIT images so debug messages
540 are a waste of code space. If you are debugging your images then
541 you can enable this option to get more verbose information about
544 config FIT_BEST_MATCH
545 bool "Select the best match for the kernel device tree"
547 When no configuration is explicitly selected, default to the
548 one whose fdt's compatibility field best matches that of
549 U-Boot itself. A match is considered "best" if it matches the
550 most specific compatibility entry of U-Boot's fdt's root node.
551 The order of entries in the configuration's fdt is ignored.
553 config FIT_IMAGE_POST_PROCESS
554 bool "Enable post-processing of FIT artifacts after loading by U-Boot"
555 depends on TI_SECURE_DEVICE
557 Allows doing any sort of manipulation to blobs after they got extracted
558 from FIT images like stripping off headers or modifying the size of the
559 blob, verification, authentication, decryption etc. in a platform or
560 board specific way. In order to use this feature a platform or board-
561 specific implementation of board_fit_image_post_process() must be
562 provided. Also, anything done during this post-processing step would
563 need to be comprehended in how the images were prepared before being
564 injected into the FIT creation (i.e. the blobs would have been pre-
565 processed before being added to the FIT image).
570 bool "Support Flattened Image Tree within SPL"
575 bool "Support FIT printing within SPL"
578 Support printing the content of the fitImage in a verbose manner in SPL.
580 config SPL_FIT_SIGNATURE
581 bool "Enable signature verification of FIT firmware within SPL"
584 select SPL_CRYPTO_SUPPORT
585 select SPL_HASH_SUPPORT
587 select SPL_RSA_VERIFY
588 select SPL_IMAGE_SIGN_INFO
591 bool "Enable SPL loading U-Boot as a FIT (basic fitImage features)"
594 Normally with the SPL framework a legacy image is generated as part
595 of the build. This contains U-Boot along with information as to
596 where it should be loaded. This option instead enables generation
597 of a FIT (Flat Image Tree) which provides more flexibility. In
598 particular it can handle selecting from multiple device tree
599 and passing the correct one to U-Boot.
601 config SPL_LOAD_FIT_ADDRESS
602 hex "load address of fit image"
603 depends on SPL_LOAD_FIT
606 Specify the load address of the fit image that will be loaded
609 config SPL_LOAD_FIT_APPLY_OVERLAY
610 bool "Enable SPL applying DT overlays from FIT"
611 depends on SPL_LOAD_FIT
612 select OF_LIBFDT_OVERLAY
614 The device tree is loaded from the FIT image. Allow the SPL is to
615 also load device-tree overlays from the FIT image an apply them
616 over the device tree.
618 config SPL_LOAD_FIT_APPLY_OVERLAY_BUF_SZ
619 depends on SPL_LOAD_FIT_APPLY_OVERLAY
621 hex "size of temporary buffer used to load the overlays"
623 The size of the area where the overlays will be loaded and
624 uncompress. Must be at least as large as biggest overlay
627 config SPL_LOAD_FIT_FULL
628 bool "Enable SPL loading U-Boot as a FIT (full fitImage features)"
631 Normally with the SPL framework a legacy image is generated as part
632 of the build. This contains U-Boot along with information as to
633 where it should be loaded. This option instead enables generation
634 of a FIT (Flat Image Tree) which provides more flexibility. In
635 particular it can handle selecting from multiple device tree
636 and passing the correct one to U-Boot.
638 config SPL_FIT_IMAGE_POST_PROCESS
639 bool "Enable post-processing of FIT artifacts after loading by the SPL"
640 depends on SPL_LOAD_FIT
642 Allows doing any sort of manipulation to blobs after they got extracted
643 from the U-Boot FIT image like stripping off headers or modifying the
644 size of the blob, verification, authentication, decryption etc. in a
645 platform or board specific way. In order to use this feature a platform
646 or board-specific implementation of board_fit_image_post_process() must
647 be provided. Also, anything done during this post-processing step would
648 need to be comprehended in how the images were prepared before being
649 injected into the FIT creation (i.e. the blobs would have been pre-
650 processed before being added to the FIT image).
652 config SPL_FIT_SOURCE
653 string ".its source file for U-Boot FIT image"
656 Specifies a (platform specific) FIT source file to generate the
657 U-Boot FIT image. This could specify further image to load and/or
660 config USE_SPL_FIT_GENERATOR
661 bool "Use a script to generate the .its script"
664 config SPL_FIT_GENERATOR
665 string ".its file generator script for U-Boot FIT image"
666 depends on USE_SPL_FIT_GENERATOR
667 default "board/sunxi/mksunxi_fit_atf.sh" if SPL_LOAD_FIT && ARCH_SUNXI
668 default "arch/arm/mach-rockchip/make_fit_atf.py" if SPL_LOAD_FIT && ARCH_ROCKCHIP
669 default "arch/arm/mach-zynqmp/mkimage_fit_atf.sh" if SPL_LOAD_FIT && ARCH_ZYNQMP
670 default "arch/riscv/lib/mkimage_fit_opensbi.sh" if SPL_LOAD_FIT && RISCV
672 Specifies a (platform specific) script file to generate the FIT
673 source file used to build the U-Boot FIT image file. This gets
674 passed a list of supported device tree file stub names to
675 include in the generated image.
681 config LEGACY_IMAGE_FORMAT
682 bool "Enable support for the legacy image format"
683 default y if !FIT_SIGNATURE
685 This option enables the legacy image format. It is enabled by
686 default for backward compatibility, unless FIT_SIGNATURE is
687 set where it is disabled so that unsigned images cannot be
688 loaded. If a board needs the legacy image format support in this
689 case, enable it here.
691 config OF_BOARD_SETUP
692 bool "Set up board-specific details in device tree before boot"
695 This causes U-Boot to call ft_board_setup() before booting into
696 the Operating System. This function can set up various
697 board-specific information in the device tree for use by the OS.
698 The device tree is then passed to the OS.
700 config OF_SYSTEM_SETUP
701 bool "Set up system-specific details in device tree before boot"
704 This causes U-Boot to call ft_system_setup() before booting into
705 the Operating System. This function can set up various
706 system-specific information in the device tree for use by the OS.
707 The device tree is then passed to the OS.
709 config OF_STDOUT_VIA_ALIAS
710 bool "Update the device-tree stdout alias from U-Boot"
713 This uses U-Boot's serial alias from the aliases node to update
714 the device tree passed to the OS. The "linux,stdout-path" property
715 in the chosen node is set to point to the correct serial node.
716 This option currently references CONFIG_CONS_INDEX, which is
717 incorrect when used with device tree as this option does not
718 exist / should not be used.
720 config SYS_EXTRA_OPTIONS
721 string "Extra Options (DEPRECATED)"
723 The old configuration infrastructure (= mkconfig + boards.cfg)
724 provided the extra options field. If you have something like
725 "HAS_BAR,BAZ=64", the optional options
727 #define CONFIG_BAZ 64
728 will be defined in include/config.h.
729 This option was prepared for the smooth migration from the old
730 configuration to Kconfig. Since this option will be removed sometime,
731 new boards should not use this option.
733 config HAVE_SYS_TEXT_BASE
735 depends on !NIOS2 && !XTENSA
740 depends on HAVE_SYS_TEXT_BASE
741 default 0x80800000 if ARCH_OMAP2PLUS || ARCH_K3
742 default 0x4a000000 if ARCH_SUNXI && !MACH_SUN9I && !MACH_SUN8I_V3S
743 default 0x2a000000 if ARCH_SUNXI && MACH_SUN9I
744 default 0x42e00000 if ARCH_SUNXI && MACH_SUN8I_V3S
747 The address in memory that U-Boot will be running from, initially.
750 depends on ARC || ARCH_SUNXI || MPC83xx
751 int "CPU clock frequency"
753 TODO: Move CONFIG_SYS_CLK_FREQ for all the architecture
755 config ARCH_FIXUP_FDT_MEMORY
756 bool "Enable arch_fixup_memory_banks() call"
759 Enable FDT memory map syncup before OS boot. This feature can be
760 used for booting OS with different memory setup where the part of
761 the memory location should be used for different purpose.
763 endmenu # Boot images
767 source "common/Kconfig"
771 source "disk/Kconfig"
779 source "drivers/Kconfig"
785 source "test/Kconfig"