I would like to flash a new u-boot by using dd command?
I have tried steps below but failed.
dd if=/dev/zero of=/dev/mmcblk0 seek=8192 count=8192
dd if=/path/to/new/u-boot of=/dev/mmcblk0 bs=1 seek=4194304 count=432068(size of the new u-boot)
Any comments are appreciated!
We are summarizing the steps for this. Will update once having conclusion.
I finally success to reflash the new u-boot in a running system.
In addition to flash a new u-boot, we need to flash the corresponding BCT image (I guess so) into mmc boot partition.
But I don’t know how to generate the BCT image(??) so far.
So we need to dump the corresponding BCT image from the device which flashed the new u-boot.
I do this by following steps.
Let MMC boot partition can be accessed. Please refer to link below.
Flash the new u-boot by using nvidia flash tool. When system boot up, dump boot.bin form /dev/mmcblk0boot0.
$ dd if=/dev/mmcblk0boot0 of=boot.bin
Flash another u-boot by using nvidia flash tool.
Flash new u-boot in running system.
$ dd if=/dev/zero of=/dev/mmcblk0 seek=8192 count=8192
$ dd if=/path/to/new/u-boot of=/dev/mmcblk0 bs=1 seek=4194304 count=432068
Add ended byte in the end of the new u-boot.
$ echo -n $'\x80' | dd of=/dev/mmcblk0 bs=1 seek=4626372
Flash the corresponding BCT image into mmc boot partition.
$ dd if=boot.bin of=/dev/mmcblk0boot0
My questions are
- Is the BCT image in mmcblk0boot0?
- How could I generate this image in mmcblk0boot0 by myself?
Yes, BCT image is in “/dev/mmcblk0boot0”
Do you see a tool named " mkbctpart" under Jetpack folder? That tool can help you regenerate BCT and uboot image.