Add a board-specific README that documents how to write u-boot.ais to the SPI found on this board.
Changes-series: 2 - Add
Signed-off-by: Tom Rini trini@ti.com ---
board/davinci/da8xxevm/README.da850_am18xxevm | 53 +++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 board/davinci/da8xxevm/README.da850_am18xxevm
diff --git a/board/davinci/da8xxevm/README.da850_am18xxevm b/board/davinci/da8xxevm/README.da850_am18xxevm new file mode 100644 index 0000000..382b718 --- /dev/null +++ b/board/davinci/da8xxevm/README.da850_am18xxevm @@ -0,0 +1,53 @@ +Summary +======= +The README is for the boot procedure used for the LogicPD AM1808 EVM. + +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 initialises the memory and the SPI controller and reads the AIS image +starting at block 0. This image can contain both the SPL and U-Boot +binaries. + +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 SPI to DDR and jumps to the u-boot +entry point. + + +Compilation +=========== +To build a SPI-bootable image, run 'make da850_am18xxevm'. This will build +the u-boot.ais file that needs to be written to SPI flash. + + +Flashing the images to Nand +=========================== +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 a UBL file and u-boot.bin. Once the system is running +again from these tools a good u-boot.ais may be re-written to SPI flash. + + +Links +===== +[1] + http://processors.wiki.ti.com/index.php/Serial_Boot_and_Flash_Loading_Utilit...