This is mainline a copy of README.m28 changing the references to the mx28 counterpart but it makes easy for people looking for information about mx28 based boards.
Signed-off-by: Otavio Salvador otavio@ossystems.com.br Cc: Fabio Estevam fabio.estevam@freescale.com --- doc/README.mx28 | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 152 insertions(+), 0 deletions(-) create mode 100644 doc/README.mx28
diff --git a/doc/README.mx28 b/doc/README.mx28 new file mode 100644 index 0000000..a68ad72 --- /dev/null +++ b/doc/README.mx28 @@ -0,0 +1,152 @@ +Freescale MX28EVK +================= + +This document describes the Freescale MX28EVK U-Boot port. This document mostly +covers topics related to making the module/board bootable. + +Terminology +----------- + +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 +-------- + +0) Files of the MX28EVK port +1) Prerequisites +2) Compiling U-Boot for MX28EVK +3) Installation of U-Boot for MX28EVK to SD card + +0) Files of the MX28EVK port +---------------------------- + +arch/arm/cpu/arm926ejs/mx28/ - The CPU support code for the Freescale i.MX28 +arch/arm/include/asm/arch-mx28/ - Header files for the Freescale i.MX28 +board/denx/mx28evk/ - MX28EVK board specific files +include/configs/mx28evk.h - MX28EVK configuration file + +1) Prerequisites +---------------- + +To make the MX28EVK board bootable, some tools are necessary. The first one is +the "elftosb" tool distributed by Freescale Semiconductor. The other tool is the +"mxsboot" tool found in U-Boot source tree. + +Firstly, obtain the elftosb archive from the following location: + + http://foss.doredevelopment.dk/mirrors/imx/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 http://foss.doredevelopment.dk/mirrors/imx/elftosb-$%7BVER%7D.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 MX28 +---------------------------- + +Compiling the U-Boot for MX28 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 MX28EVK: + + $ make mx28evk_config + +Lastly, compile U-Boot and prepare a "BootStream". The "BootStream" is a special +type of file, which the i.MX28 CPU 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. + +3) Installation of U-Boot for MX28EVK to SD card +------------------------------------------------ + +To boot an MX28 from SD, set the boot mode DIP switches as: + + * Boot Mode Select: 1 0 0 1 (Boot from SD card Slot 0 - U42) + * JTAG PSWITCH RESET: To the left (reset enabled) + * Battery Source: Down + * Wall 5V: Up + * VDD 5V: To the left (off) + * Hold Button: Down (off) + +Full reference at i.MX28 manual chapter 12.2.1 (Table 12-2). + +An SD card that can be used to boot U-Boot on a i.MX28 CPU 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 MX28EVK 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.