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authorStephen Warren <swarren@nvidia.com>2013-10-03 13:07:16 -0600
committerStephen Warren <swarren@nvidia.com>2013-10-03 13:09:05 -0600
commitcaa74de0a7ebcbafd4c81809587316c1a42188e0 (patch)
treedaff04c1d8caad960b05eb1e27bf1174c96509c7
parentcda386b038294240784f39fff9a800ac08929af4 (diff)
downloadcbootimage-configs-caa74de0a7ebcbafd4c81809587316c1a42188e0.tar.gz
Update README to describe tegrarcm readbct command
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@nvidia.com>
-rw-r--r--README.txt35
1 files 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)