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Diffstat (limited to 'qemu/roms/u-boot/board/davinci/da8xxevm/README.hawkboard')
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diff --git a/qemu/roms/u-boot/board/davinci/da8xxevm/README.hawkboard b/qemu/roms/u-boot/board/davinci/da8xxevm/README.hawkboard new file mode 100644 index 000000000..d6ae02ec0 --- /dev/null +++ b/qemu/roms/u-boot/board/davinci/da8xxevm/README.hawkboard @@ -0,0 +1,92 @@ +Summary +======= +The README is for the boot procedure used for TI's OMAP-L138 based +hawkboard. The hawkboard comes with a 128MiB Nand flash and a 128MiB +DDR SDRAM along with a host of other controllers. + +The hawkboard is booted in three stages. The initial bootloader which +executes upon reset is the Rom Boot Loader(RBL) which sits in the +internal ROM of the omap. The RBL initialises the memory and the nand +controller, and copies the image stored at a predefined location(block +1) of the nand flash. The image loaded by the RBL to the memory is the +AIS signed spl image. This, in turns copies the u-boot binary from the +nand flash to the memory 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 secondary stage bootloader(spl) which is loaded by the RBL then +loads the u-boot from a predefined location in the nand to the memory +and jumps to the u-boot entry point. + +The reason a secondary stage bootloader is used is because the ECC +layout expected by the RBL is not the same as that used by +u-boot/linux. This also implies that for flashing the spl image,we +need to use the u-boot which uses the ECC layout expected by the +RBL[1]. Booting u-boot over UART(UART boot) is explained here[2]. + + +Compilation +=========== +Three images might be needed + +* spl - This is the secondary bootloader which boots the u-boot + binary. + +* u-boot binary - This is the image flashed to the nand and copied to + the memory by the spl. + + Both the images get compiled with hawkboard_config, with the TOPDIR + containing the u-boot images, and the spl image under the spl + directory. + + The spl image needs to be processed with the AISGen tool for + generating the AIS signed image to be flashed. Steps for generating + the AIS image are explained here[3]. + +* u-boot for uart boot - This is same as the u-boot binary generated + above, with the sole difference of the CONFIG_SYS_TEXT_BASE being + 0xc1080000, as expected by the RBL. + + hawkboard_uart_config + + +Flashing the images to Nand +=========================== +The spl AIS image needs to be flashed to the block 1 of the Nand +flash, as that is the location the RBL expects the image[4]. For +flashing the spl, boot over the u-boot specified in [1], and flash the +image + +=> tftpboot 0xc0700000 <nand_spl_ais.bin> +=> nand erase 0x20000 0x20000 +=> nand write.e 0xc0700000 0x20000 <nand_spl_size> + +The u-boot binary is flashed at location 0xe0000(block 6) of the nand +flash. The spl loader expects the u-boot at this location. For +flashing the u-boot binary + +=> tftpboot 0xc0700000 u-boot.bin +=> nand erase 0xe0000 0x40000 +=> nand write.e 0xc0700000 0xe0000 <u-boot-size> + + +Links +===== + +[1] + http://code.google.com/p/hawkboard/downloads/detail?name=u-boot_uart_ais_v1.bin + +[2] + http://elinux.org/Hawkboard#Booting_u-boot_over_UART + +[3] + http://elinux.org/Hawkboard#Signing_u-boot_for_UART_boot + +[4] + http://processors.wiki.ti.com/index.php/RBL_UBL_and_host_program#RBL_booting_from_NAND_and_ECC.2FBad_blocks |