This file documents when to build for da850evm and when to build for da850_am18xxevm. It also documents how to write the u-boot.ais file to persistent storage (such as SPI), in some cases as well as how to write a recovery image.
Signed-off-by: Tom Rini trini@ti.com --- Changes in v2: - Add README.da850_am18xxevm
Changes in v3: - Fix thinko, Nand -> SPI (spotted by Prabhakar Lad) - Rename to README.da850, add more direct recovery method (Christian Riesch)
Changes in v4: - Further re-word README.da850 based on feedback from Christian Riesch
board/davinci/da8xxevm/README.da850 | 68 +++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 board/davinci/da8xxevm/README.da850
diff --git a/board/davinci/da8xxevm/README.da850 b/board/davinci/da8xxevm/README.da850 new file mode 100644 index 0000000..621a95d --- /dev/null +++ b/board/davinci/da8xxevm/README.da850 @@ -0,0 +1,68 @@ +Summary +======= +The README is for the boot procedure used for various DA850 (or compatible +parts such as the AM1808) based boards. + +In the context of U-Boot, the board is booted in three stages. The initial +bootloader which executes upon reset is the ROM Boot Loader (RBL) and sits +in the internal ROM. The RBL initializes the internal memory and then +depending on the exact board and pin configurations will initialize another +controller (such as SPI or NAND) to continue the boot process by loading +the secondary program loader (SPL). The SPL will initialize the system +further (some clocks, SDRAM) and then load the full u-boot from a +predefined location in persistent storage to DDR and jumps to the u-boot +entry point. + +AIS is an image format defined by TI for the images that are to be loaded +to memory by the RBL. The image is divided into a series of sections and +the image's entry point is specified. Each section comes with meta data +like the target address the section is to be copied to and the size of the +section, which is used by the RBL to load the image. At the end of the +image the RBL jumps to the image entry point. The AIS format allows for +other things such as programming the clocks and SDRAM if the header is +programmed for it. We do not take advantage of this and instead use SPL as +it allows for additional flexibility (run-time detect of board revision, +loading the next image from a different media, etc). + + +Compilation +=========== +The exact build target you need will depend on the board you have. For +Logic PD boards, or other boards which store the ethernet MAC address at +the end of SPI flash, run 'make da850evm'. For boards which store the +ethernet MAC address in the i2c EEPROM located at 0x50, run +'make da850_am18xxevm'. Once this build completes you will have a +u-boot.ais file that needs to be written to the correct persistent +storage. + + +Flashing the images to SPI +========================== +The AIS image can be written to SPI flash using the following commands. +Assuming that the network is configured and enabled and the u-boot.ais file +is tftp'able. + +U-Boot > sf probe 0 +U-Boot > sf erase 0 +320000 +U-Boot > tftp u-boot.ais +U-Boot > sf write c0700000 0 $filesize + + +Recovery +======== + +In the case of a "bricked" board, you need to use the TI tools found +here[1] to write the u-boot.ais file. An example of recovering to the SPI +flash of an AM1808 would be: + +$ mono sfh_OMAP-L138.exe -targetType AM1808 -p /dev/ttyUSB0 \ + -flash_noubl /path/to/u-boot.ais + +For other target types and flash locations: + +$ mono sfh_OMAP-L138.exe -h + +Links +===== +[1] + http://processors.wiki.ti.com/index.php/Serial_Boot_and_Flash_Loading_Utilit...