[J-u-boot.git] / doc / README.mxs

Booting U-boot on a MXS processor
=================================

This document describes the MXS U-Boot port. This document mostly covers topics
related to making the module/board bootable.

Terminology
-----------

The term "MXS" refers to a family of Freescale SoCs that is composed by MX23
and MX28.

The dollar symbol ($) introduces a snipped of shell code. This shall be typed
into the unix command prompt in U-Boot source code root directory.

The (=>) introduces a snipped of code that should by typed into U-Boot command
prompt

Contents
--------

1) Prerequisites
2) Compiling U-Boot for a MXS based board
3) Installation of U-Boot for a MXS based board to SD card
4) Installation of U-Boot into NAND flash on a MX28 based board

1) Prerequisites
----------------

To make a MXS based board bootable, some tools are necessary. The only
mandatory tool is the "mxsboot" tool found in U-Boot source tree. The
tool is built automatically when compiling U-Boot for i.MX23 or i.MX28.

The production of BootStream image is handled via "mkimage", which is
also part of the U-Boot source tree. The "mkimage" requires OpenSSL
development libraries to be installed. In case of Debian and derivates,
this is installed by running:

	$ sudo apt-get install libssl-dev

NOTE: The "elftosb" tool distributed by Freescale Semiconductor is no
      longer necessary for general use of U-Boot on i.MX23 and i.MX28.
      The mkimage supports generation of BootStream images encrypted
      with a zero key, which is the vast majority of use-cases. In
      case you do need to produce image encrypted with non-zero key
      or other special features, please use the "elftosb" tool,
      otherwise continue to section 2). The installation procedure of
      the "elftosb" is outlined below:

Firstly, obtain the elftosb archive from the following location:

	ftp://ftp.denx.de/pub/tools/elftosb-10.12.01.tar.gz

We use a $VER variable here to denote the current version. At the time of
writing of this document, that is "10.12.01". To obtain the file from command
line, use:

	$ VER="10.12.01"
	$ wget ftp://ftp.denx.de/pub/tools/elftosb-${VER}.tar.gz

Extract the file:

	$ tar xzf elftosb-${VER}.tar.gz

Compile the file. We need to manually tell the linker to use also libm:

	$ cd elftosb-${VER}/
	$ make LIBS="-lstdc++ -lm" elftosb

Optionally, remove debugging symbols from elftosb:

	$ strip bld/linux/elftosb

Finally, install the "elftosb" binary. The "install" target is missing, so just
copy the binary by hand:

	$ sudo cp bld/linux/elftosb /usr/local/bin/

Make sure the "elftosb" binary can be found in your $PATH, in this case this
means "/usr/local/bin/" has to be in your $PATH.

2) Compiling U-Boot for a MXS based board
-------------------------------------------

Compiling the U-Boot for a MXS board is straightforward and done as compiling
U-Boot for any other ARM device. For cross-compiler setup, please refer to
ELDK5.0 documentation. First, clean up the source code:

	$ make mrproper

Next, configure U-Boot for a MXS based board

	$ make <mxs_based_board_name>_config

Examples:

1. For building U-boot for Denx M28EVK board:

	$ make m28evk_config

2. For building U-boot for Freescale MX28EVK board:

	$ make mx28evk_config

3. For building U-boot for Freescale MX23EVK board:

	$ make mx23evk_config

4. For building U-boot for Olimex MX23 Olinuxino board:

	$ make mx23_olinuxino_config

Lastly, compile U-Boot and prepare a "BootStream". The "BootStream" is a special
type of file, which MXS CPUs can boot. This is handled by the following
command:

	$ make u-boot.sb

HINT: To speed-up the build process, you can add -j<N>, where N is number of
      compiler instances that'll run in parallel.

The code produces "u-boot.sb" file. This file needs to be augmented with a
proper header to allow successful boot from SD or NAND. Adding the header is
discussed in the following chapters.

NOTE: The process that produces u-boot.sb uses the mkimage to generate the
      BootStream. The BootStream is encrypted with zero key. In case you need
      some special features of the BootStream and plan on using the "elftosb"
      tool instead, the invocation to produce a compatible BootStream with the
      one produced by mkimage is outlined below. For further details, refer to
      the documentation bundled with the "elftosb" package.

	$ elftosb -zf imx23 -c arch/arm/cpu/arm926ejs/mxs/u-boot-imx23.bd \
		-o u-boot.sb
	$ elftosb -zf imx28 -c arch/arm/cpu/arm926ejs/mxs/u-boot-imx28.bd \
		-o u-boot.sb

3) Installation of U-Boot for a MXS based board to SD card
----------------------------------------------------------

To boot a MXS based board from SD, set the boot mode DIP switches according to
to MX28 manual, section 12.2.1 (Table 12-2) or MX23 manual, section 35.1.2
(Table 35-3).

The SD card used to boot U-Boot must contain a DOS partition table, which in
turn carries a partition of special type and which contains a special header.
The rest of partitions in the DOS partition table can be used by the user.

To prepare such partition, use your favourite partitioning tool. The partition
must have the following parameters:

	* Start sector .......... sector 2048
	* Partition size ........ at least 1024 kb
	* Partition type ........ 0x53 (sometimes "OnTrack DM6 Aux3")

For example in Linux fdisk, the sequence for a clear card follows. Be sure to
run fdisk with the option "-u=sectors" to set units to sectors:

	* o ..................... create a clear partition table
	* n ..................... create new partition
		* p ............. primary partition
		* 1 ............. first partition
		* 2048 .......... first sector is 2048
		* +1M ........... make the partition 1Mb big
	* t 1 ................... change first partition ID
		* 53 ............ change the ID to 0x53 (OnTrack DM6 Aux3)
	* <create other partitions>
	* w ..................... write partition table to disk

The partition layout is ready, next the special partition must be filled with
proper contents. The contents is generated by running the following command
(see chapter 2)):

	$ ./tools/mxsboot sd u-boot.sb u-boot.sd

The resulting file, "u-boot.sd", shall then be written to the partition. In this
case, we assume the first partition of the SD card is /dev/mmcblk0p1:

	$ dd if=u-boot.sd of=/dev/mmcblk0p1

Last step is to insert the card into the MXS based board and boot.

NOTE: If the user needs to adjust the start sector, the "mxsboot" tool contains
      a "-p" switch for that purpose. The "-p" switch takes the sector number as
      an argument.

4) Installation of U-Boot into NAND flash on a MX28 based board
---------------------------------------------------------------

To boot a MX28 based board from NAND, set the boot mode DIP switches according
to MX28 manual section 12.2.1 (Table 12-2), PORT=GPMI, NAND 1.8 V.

There are two possibilities when preparing an image writable to NAND flash.

	I) The NAND wasn't written at all yet or the BCB is broken
	----------------------------------------------------------
	   In this case, both BCB (FCB and DBBT) and firmware needs to be
	   written to NAND. To generate NAND image containing all these,
	   there is a tool called "mxsboot" in the "tools/" directory. The tool
	   is invoked on "u-boot.sb" file from chapter 2):

		 $ ./tools/mxsboot nand u-boot.sb u-boot.nand

	   NOTE: The above invokation works for NAND flash with geometry of
		 2048b per page, 64b OOB data, 128kb erase size. If your chip
		 has a different geometry, please use:

		 -w <size>	change page size (default 2048 b)
		 -o <size>	change oob size (default 64 b)
		 -e <size>	change erase size (default 131072 b)

		 The geometry information can be obtained from running U-Boot
		 on the MX28 board by issuing the "nand info" command.

	   The resulting file, "u-boot.nand" can be written directly to NAND
	   from the U-Boot prompt. To simplify the process, the U-Boot default
	   environment contains script "update_nand_full" to update the system.

	   This script expects a working TFTP server containing the file
	   "u-boot.nand" in it's root directory. This can be changed by
	   adjusting the "update_nand_full_filename" varible.

	   To update the system, run the following in U-Boot prompt:

		 => run update_nand_full

	   In case you would only need to update the bootloader in future,
	   see II) below.

	II) The NAND was already written with a good BCB
	------------------------------------------------
	   This part applies after the part I) above was done at least once.

	   If part I) above was done correctly already, there is no need to
	   write the FCB and DBBT parts of NAND again. It's possible to upgrade
	   only the bootloader image.

	   To simplify the process of firmware update, the U-Boot default
	   environment contains script "update_nand_firmware" to update only
	   the firmware, without rewriting FCB and DBBT.

	   This script expects a working TFTP server containing the file
	   "u-boot.sb" in it's root directory. This can be changed by
	   adjusting the "update_nand_firmware_filename" varible.

	   To update the system, run the following in U-Boot prompt:

		 => run update_nand_firmware

	III) Special settings for the update scripts
	--------------------------------------------
	   There is a slight possibility of the user wanting to adjust the
	   STRIDE and COUNT options of the NAND boot. For description of these,
	   see MX28 manual section 12.12.1.2 and 12.12.1.3.

	   The update scripts take this possibility into account. In case the
	   user changes STRIDE by blowing fuses, the user also has to change
	   "update_nand_stride" variable. In case the user changes COUNT by
	   blowing fuses, the user also has to change "update_nand_count"
	   variable for the update scripts to work correctly.

	   In case the user needs to boot a firmware image bigger than 1Mb, the
	   user has to adjust the "update_nand_firmware_maxsz" variable for the
	   update scripts to work properly.
Commit	Line	Data
54965b61 FE	1	Booting U-boot on a MXS processor
54965b61 FE	2	=================================
419ea2d8	3
54965b61 FE	4	This document describes the MXS U-Boot port. This document mostly covers topics
54965b61 FE	5	related to making the module/board bootable.
419ea2d8 FE	6
	7	Terminology
	8	-----------
	9
54965b61 FE	10	The term "MXS" refers to a family of Freescale SoCs that is composed by MX23
	11	and MX28.
	12
419ea2d8 FE	13	The dollar symbol ($) introduces a snipped of shell code. This shall be typed
	14	into the unix command prompt in U-Boot source code root directory.
	15
	16	The (=>) introduces a snipped of code that should by typed into U-Boot command
	17	prompt
	18
	19	Contents
	20	--------
	21
	22	1) Prerequisites
54965b61 FE	23	2) Compiling U-Boot for a MXS based board
	24	3) Installation of U-Boot for a MXS based board to SD card
	25	4) Installation of U-Boot into NAND flash on a MX28 based board
419ea2d8 FE	26
	27	1) Prerequisites
	28	----------------
	29
6654f33c MV	30	To make a MXS based board bootable, some tools are necessary. The only
	31	mandatory tool is the "mxsboot" tool found in U-Boot source tree. The
	32	tool is built automatically when compiling U-Boot for i.MX23 or i.MX28.
	33
	34	The production of BootStream image is handled via "mkimage", which is
	35	also part of the U-Boot source tree. The "mkimage" requires OpenSSL
	36	development libraries to be installed. In case of Debian and derivates,
	37	this is installed by running:
	38
	39	$ sudo apt-get install libssl-dev
	40
	41	NOTE: The "elftosb" tool distributed by Freescale Semiconductor is no
	42	longer necessary for general use of U-Boot on i.MX23 and i.MX28.
	43	The mkimage supports generation of BootStream images encrypted
	44	with a zero key, which is the vast majority of use-cases. In
	45	case you do need to produce image encrypted with non-zero key
	46	or other special features, please use the "elftosb" tool,
	47	otherwise continue to section 2). The installation procedure of
	48	the "elftosb" is outlined below:
419ea2d8 FE	49
	50	Firstly, obtain the elftosb archive from the following location:
	51
9de1c22f	52	ftp://ftp.denx.de/pub/tools/elftosb-10.12.01.tar.gz
419ea2d8 FE	53
	54	We use a $VER variable here to denote the current version. At the time of
	55	writing of this document, that is "10.12.01". To obtain the file from command
	56	line, use:
	57
	58	$ VER="10.12.01"
9de1c22f	59	$ wget ftp://ftp.denx.de/pub/tools/elftosb-${VER}.tar.gz
419ea2d8 FE	60
	61	Extract the file:
	62
	63	$ tar xzf elftosb-${VER}.tar.gz
	64
	65	Compile the file. We need to manually tell the linker to use also libm:
	66
	67	$ cd elftosb-${VER}/
	68	$ make LIBS="-lstdc++ -lm" elftosb
	69
	70	Optionally, remove debugging symbols from elftosb:
	71
	72	$ strip bld/linux/elftosb
	73
	74	Finally, install the "elftosb" binary. The "install" target is missing, so just
	75	copy the binary by hand:
	76
	77	$ sudo cp bld/linux/elftosb /usr/local/bin/
	78
	79	Make sure the "elftosb" binary can be found in your $PATH, in this case this
	80	means "/usr/local/bin/" has to be in your $PATH.
	81
54965b61	82	2) Compiling U-Boot for a MXS based board
419ea2d8 FE	83	-------------------------------------------
419ea2d8 FE	84
54965b61	85	Compiling the U-Boot for a MXS board is straightforward and done as compiling
84286c22 FE	86	U-Boot for any other ARM device. For cross-compiler setup, please refer to
84286c22 FE	87	ELDK5.0 documentation. First, clean up the source code:
419ea2d8 FE	88
	89	$ make mrproper
	90
54965b61	91	Next, configure U-Boot for a MXS based board
419ea2d8	92
54965b61	93	$ make <mxs_based_board_name>_config
419ea2d8 FE	94
	95	Examples:
	96
	97	1. For building U-boot for Denx M28EVK board:
	98
	99	$ make m28evk_config
	100
	101	2. For building U-boot for Freescale MX28EVK board:
	102
	103	$ make mx28evk_config
	104
54965b61 FE	105	3. For building U-boot for Freescale MX23EVK board:
	106
	107	$ make mx23evk_config
	108
	109	4. For building U-boot for Olimex MX23 Olinuxino board:
	110
	111	$ make mx23_olinuxino_config
	112
419ea2d8	113	Lastly, compile U-Boot and prepare a "BootStream". The "BootStream" is a special
54965b61	114	type of file, which MXS CPUs can boot. This is handled by the following
419ea2d8 FE	115	command:
	116
	117	$ make u-boot.sb
	118
	119	HINT: To speed-up the build process, you can add -j<N>, where N is number of
	120	compiler instances that'll run in parallel.
	121
	122	The code produces "u-boot.sb" file. This file needs to be augmented with a
	123	proper header to allow successful boot from SD or NAND. Adding the header is
	124	discussed in the following chapters.
	125
6654f33c MV	126	NOTE: The process that produces u-boot.sb uses the mkimage to generate the
	127	BootStream. The BootStream is encrypted with zero key. In case you need
	128	some special features of the BootStream and plan on using the "elftosb"
	129	tool instead, the invocation to produce a compatible BootStream with the
	130	one produced by mkimage is outlined below. For further details, refer to
	131	the documentation bundled with the "elftosb" package.
	132
	133	$ elftosb -zf imx23 -c arch/arm/cpu/arm926ejs/mxs/u-boot-imx23.bd \
	134	-o u-boot.sb
	135	$ elftosb -zf imx28 -c arch/arm/cpu/arm926ejs/mxs/u-boot-imx28.bd \
	136	-o u-boot.sb
	137
54965b61 FE	138	3) Installation of U-Boot for a MXS based board to SD card
54965b61 FE	139	----------------------------------------------------------
419ea2d8	140
54965b61 FE	141	To boot a MXS based board from SD, set the boot mode DIP switches according to
	142	to MX28 manual, section 12.2.1 (Table 12-2) or MX23 manual, section 35.1.2
	143	(Table 35-3).
419ea2d8	144
7333eca5 FE	145	The SD card used to boot U-Boot must contain a DOS partition table, which in
	146	turn carries a partition of special type and which contains a special header.
	147	The rest of partitions in the DOS partition table can be used by the user.
419ea2d8 FE	148
	149	To prepare such partition, use your favourite partitioning tool. The partition
	150	must have the following parameters:
	151
	152	* Start sector .......... sector 2048
	153	* Partition size ........ at least 1024 kb
	154	* Partition type ........ 0x53 (sometimes "OnTrack DM6 Aux3")
	155
	156	For example in Linux fdisk, the sequence for a clear card follows. Be sure to
	157	run fdisk with the option "-u=sectors" to set units to sectors:
	158
	159	* o ..................... create a clear partition table
	160	* n ..................... create new partition
	161	* p ............. primary partition
	162	* 1 ............. first partition
	163	* 2048 .......... first sector is 2048
	164	* +1M ........... make the partition 1Mb big
	165	* t 1 ................... change first partition ID
	166	* 53 ............ change the ID to 0x53 (OnTrack DM6 Aux3)
	167	* <create other partitions>
	168	* w ..................... write partition table to disk
	169
	170	The partition layout is ready, next the special partition must be filled with
	171	proper contents. The contents is generated by running the following command
	172	(see chapter 2)):
	173
	174	$ ./tools/mxsboot sd u-boot.sb u-boot.sd
	175
	176	The resulting file, "u-boot.sd", shall then be written to the partition. In this
	177	case, we assume the first partition of the SD card is /dev/mmcblk0p1:
	178
	179	$ dd if=u-boot.sd of=/dev/mmcblk0p1
	180
54965b61	181	Last step is to insert the card into the MXS based board and boot.
419ea2d8 FE	182
	183	NOTE: If the user needs to adjust the start sector, the "mxsboot" tool contains
	184	a "-p" switch for that purpose. The "-p" switch takes the sector number as
	185	an argument.
	186
54965b61 FE	187	4) Installation of U-Boot into NAND flash on a MX28 based board
54965b61 FE	188	---------------------------------------------------------------
419ea2d8	189
84286c22	190	To boot a MX28 based board from NAND, set the boot mode DIP switches according
54965b61	191	to MX28 manual section 12.2.1 (Table 12-2), PORT=GPMI, NAND 1.8 V.
419ea2d8 FE	192
	193	There are two possibilities when preparing an image writable to NAND flash.
	194
	195	I) The NAND wasn't written at all yet or the BCB is broken
	196	----------------------------------------------------------
	197	In this case, both BCB (FCB and DBBT) and firmware needs to be
	198	written to NAND. To generate NAND image containing all these,
	199	there is a tool called "mxsboot" in the "tools/" directory. The tool
	200	is invoked on "u-boot.sb" file from chapter 2):
	201
	202	$ ./tools/mxsboot nand u-boot.sb u-boot.nand
	203
	204	NOTE: The above invokation works for NAND flash with geometry of
	205	2048b per page, 64b OOB data, 128kb erase size. If your chip
	206	has a different geometry, please use:
	207
	208	-w <size> change page size (default 2048 b)
	209	-o <size> change oob size (default 64 b)
	210	-e <size> change erase size (default 131072 b)
	211
	212	The geometry information can be obtained from running U-Boot
	213	on the MX28 board by issuing the "nand info" command.
	214
	215	The resulting file, "u-boot.nand" can be written directly to NAND
	216	from the U-Boot prompt. To simplify the process, the U-Boot default
	217	environment contains script "update_nand_full" to update the system.
	218
	219	This script expects a working TFTP server containing the file
	220	"u-boot.nand" in it's root directory. This can be changed by
	221	adjusting the "update_nand_full_filename" varible.
	222
	223	To update the system, run the following in U-Boot prompt:
	224
	225	=> run update_nand_full
	226
	227	In case you would only need to update the bootloader in future,
	228	see II) below.
	229
	230	II) The NAND was already written with a good BCB
	231	------------------------------------------------
	232	This part applies after the part I) above was done at least once.
	233
	234	If part I) above was done correctly already, there is no need to
	235	write the FCB and DBBT parts of NAND again. It's possible to upgrade
	236	only the bootloader image.
	237
	238	To simplify the process of firmware update, the U-Boot default
	239	environment contains script "update_nand_firmware" to update only
	240	the firmware, without rewriting FCB and DBBT.
	241
	242	This script expects a working TFTP server containing the file
	243	"u-boot.sb" in it's root directory. This can be changed by
	244	adjusting the "update_nand_firmware_filename" varible.
	245
	246	To update the system, run the following in U-Boot prompt:
	247
	248	=> run update_nand_firmware
	249
	250	III) Special settings for the update scripts
	251	--------------------------------------------
	252	There is a slight possibility of the user wanting to adjust the
	253	STRIDE and COUNT options of the NAND boot. For description of these,
54965b61	254	see MX28 manual section 12.12.1.2 and 12.12.1.3.
419ea2d8 FE	255
	256	The update scripts take this possibility into account. In case the
	257	user changes STRIDE by blowing fuses, the user also has to change
	258	"update_nand_stride" variable. In case the user changes COUNT by
	259	blowing fuses, the user also has to change "update_nand_count"
	260	variable for the update scripts to work correctly.
	261
	262	In case the user needs to boot a firmware image bigger than 1Mb, the
	263	user has to adjust the "update_nand_firmware_maxsz" variable for the
	264	update scripts to work properly.