From: Stephen Warren <swarren@xxxxxxxxxx> Recent versions of tegrarcm now have the capability to read the BCT from the device without requiring any HW-specific binaries, nor code already installed on the device. Mention this in the README, since it discusses ways to extract a BCT from a device. Also, fix a typo in the Linux MMC block device name that contains the BCT. Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> --- README.txt | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/README.txt b/README.txt index dfb97e2..9f742cf 100644 --- a/README.txt +++ b/README.txt @@ -15,33 +15,46 @@ using the following process: Extract the BCT from the existing device. Various methods exist to do this: +1a) + +Recent versions of tegrarcm now have the capability to read the BCT from the +device without requiring any HW-specific binaries, nor code already installed +on the device: + + tegrarcm --bct board.bct readbct + +1b) + 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 eMMC: + + dd if=/dev/mmcblk0boot0 of=bct.bin bs=65536 count=1 + +For devices which boot from SPI: + + dd if=/dev/mtd0ro of=bct.bin bs=65536 count=1 -# For devices which boot from SPI: -dd if=/dev/mtd0ro of=bct.bin bs=65536 count=1 +1c) If you have a working nvflash for your device, then this can also extract the BCT: -nvflash --bl fastboot.bin --getbct --bct board.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 + nvflash --bl fastboot.bin --read 2 board.bct or: -nvflash --bl fastboot.bin --rawdeviceread 0 128 board.bct + 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. +Note that some of the above commands 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) -- 1.8.1.5 -- 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
