How to flash an image using initrd with good performance?

[JoostBaars]

I saw in the wiki that there is a nice section about flashing with Initrd. But when using ./initrd-flash to flash the AGX Xavier Industrial, it takes about 55 minutes to fully flash the device. This is because the rootfs image is not shrunk down, and it therefore flashes the full 30gb partition.
I also updated the main partition to the shrunken down image file (I made a sparse file using mksparse, which was only 114MB), flashing took only minutes instead of 55 minutes, but then it gives errors during boot:
[ 150.204536] exFAT-fs (mmcblk0p1): invalid boot record signature
[ 150.204680] exFAT-fs (mmcblk0p1): failed to read boot sector
[ 150.204799] exFAT-fs (mmcblk0p1): failed to recognize exfat type
mount: mounting /dev/mmcblk0p1 on /mnt failed: Invalid argument

Do you know what could cause this or how to do faster flashing using initrd?

[joekale-pp]

To speed up the flash you can install bmaptool on your distribution.

[arrow53]

@joekale-pp I added bmaptool to my partition IMAGE_INSTALL:append = " bmaptool htop " but it didn't seem to change anything. Still used ext4 image. Is this because I have an external nvme on my orin nano kit?

[joekale-pp]

bmaptool needs to be installed to the host computer that performs the flash process. bmaptool is used to speed up writing sparse filesystems.

[arrow53]

wow, that really did help. Thanks!

[minicarpet]

Could you provide the command to do for flashing the board using bmaptool ? Is that:
oe-run-native bmaptool-native bmaptool copy build-directory/tmp/deploy/images/machine/image.tegraflash.tar.gz /dev/mmcblk0p1 ?

[dwalkes]

Could you provide the command to do for flashing the board using bmaptool

It's used here as a part if initrd-flash when you use this method to flash your device.