From: Stephen Warren <swarren@xxxxxxxxxx> Create a README.txt file for cbootimage-configs. This mainly describes how to obtain/extract equivalent config files for boards that are not yet supported by the project. Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> Acked-by: Eric Brower <ebrower@xxxxxxxxxx> --- README.txt | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 README.txt diff --git a/README.txt b/README.txt new file mode 100644 index 0000000..dfb97e2 --- /dev/null +++ b/README.txt @@ -0,0 +1,63 @@ +The cbootimage-configs project contains cbootimage configuration files for +many Tegra boards, both those designed by NVIDIA, and various third-parties. + +The directory hierarchy is first by chip/SoC, then by vendor, then by board +name. For example, tegra20/nvidia/harmony. + +If you wish to use cbootimage with a board that is not yet supported by this +project, you might try contacting the vendor of the board to see if they'd be +willing to contribute configuration files to this project. + +If that doesn't work out, you may create the required configuration files +using the following process: + +1) + +Extract the BCT from the existing device. Various methods exist to do this: + +If you have access to Linux running on the device already, then you can use +dump the memory device directly: + +# For devices which boot from eMMC: +dd if=/dev/mmcblk0boot1 of=bct.bin bs=65536 count=1 + +# For devices which boot from SPI: +dd if=/dev/mtd0ro of=bct.bin bs=65536 count=1 + +If you have a working nvflash for your device, then this can also extract the +BCT: + +nvflash --bl fastboot.bin --getbct --bct board.bct + +If that doesn't work, you could try reading the content of the BCT partition +or the start of the raw device, then extracting the BCT: + +nvflash --bl fastboot.bin --read 2 board.bct + +or: + +nvflash --bl fastboot.bin --rawdeviceread 0 128 board.bct + +Note that all of the above commands, except the nvflash --getbct command, +extract many more bytes of data that is strictly required. However, this +avoids updating these instructions for each new chip; Tegra20's BCT is just +under 4KiB, Tegra30's around 6KiB, etc. + +2) + +Convert the BCT to a cbootimage configuration file: + +bct_dump board.bct > board.bct.cfg + +This will de-compile the extracted BCT binary into a text configuration file +suitable for later use by cbootimage. + +To follow the same structure as the rest of the configuration files in this +project, it's then best to split up board.bct.cfg into separate board.bct.cfg +(DevType, DeviceParam, and SDRAM lines), and board.img.cfg (all other header +parameters). Use the existing configuration files as a guide. + +Once you have performed these steps, you will have configuration files +suitable for your personal use. We don't accept contributions to this project +that were derived in this fashion. We encourage you to contact the vendor +and request them to submit their own configuration files. -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
