Hmmm. Maybe it doesn't work after all and I have to take back my words.
This is what it does for a factory reset:
Code:
dd if=$UBOOT_RECOVERY of=/dev/mmcblk0 bs=128k count=1 seek=6
In case of the H2O that's /etc/u-boot/mx50-ntx/u-boot.{mmc,recovery}
And the difference of this file is like:
Code:
bootcmd_SD=run bootargs_base bootargs_SD;load_ntxkernel; bootm
bootcmd_recovery=run bootargs_base bootargs_recovery;load_ntxkernel; bootm
verify=no
-bootcmd=run bootcmd_mmc
bootargs_recovery=setenv bootargs ${bootargs} root=/dev/mmcblk0p2 rootfstype=ext4
bootargs_mmc=setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootfstype=ext4
bootargs_SD=setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootfstype=ext4
+bootcmd=run bootcmd_recovery
bootargs_base=setenv bootargs console=ttymxc0,115200 rootwait rw quiet lpj=3997696
stdin=serial
stdout=serial
So it changes bootcmd_mmc (the normal internal memory) to bootcmd_recovery (the internal recovery partition) and when it boots from the recovery partition, the scripts there perform the factory reset itself and switch it back to bootcmd_mmc.
There's also a bootcmd_SD in there which should use the SD card; and I changed it to run bootcmd_SD and I thought it had worked. I put a copy of the internal filesystem to the SD card and it booted from it, or so I thought; but now when I try it again somehow I can't make it work. It did boot, but using the internal memory like normal. So now I'm no longer sure I succeeded the first time around.