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
Changes in v3: - Fix thinko, Nand -> SPI (spotted by Prabhakar Lad) - Rename to README.da850, add more direct recovery method (Christian Riesch)
board/davinci/da8xxevm/README.da850 | 62 +++++++++++++++++++++++++++++++++++ 1 file changed, 62 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..55291f3 --- /dev/null +++ b/board/davinci/da8xxevm/README.da850 @@ -0,0 +1,62 @@ +Summary +======= +The README is for the boot procedure used for various DA850 (or compatible +parts such as the AM1808) based boards. + +The board is booted in three stages. The initial bootloader which executes +upon reset is the ROM Boot Loader (RBL) which sits in the internal ROM. The +RBL initializes the memory and then depending on the exact board will +initialize another controller (such as SPI or NAND) to continue the boot +process. + +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 secondary stage bootloader (SPL) which is loaded by the RBL then loads +the u-boot from a predefined location in persistent storage to DDR and +jumps to the u-boot entry point. + + +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 $filesize + + +Recovery +======== + +In the case of a "bricked" board, you need to use the TI tools found +here[1] to write the u-boot.ais file. An example of recovering to the SPI +flash would be: + +$ mono sfh_OMAP-L138.exe -targetType AM1808 -p /dev/ttyUSB0 \ + -flash_noubl /path/to/u-boot.ais + + +Links +===== +[1] + http://processors.wiki.ti.com/index.php/Serial_Boot_and_Flash_Loading_Utilit...