How do you go about switching via uboot to a good partition?

Answer

Here are the instructions to switch partitions from u-boot: #To revert to kernel-a and rootfs-a: setenv bootargs 'console=ttyS0,115200 loglevel=4 rw noinitrd mem=64M rootfstype=ubifs root=ubi0:rootfs ubi.mtd=6' setenv bootcmd 'nand read 0x22000000 0x000E0000 0x00280000; run _mtd; bootm' saveenv #To revert to kernel-b and rootfs-b: setenv bootargs 'console=ttyS0,115200 loglevel=4 rw noinitrd mem=64M rootfstype=ubifs root=ubi0:rootfs ubi.mtd=7' setenv bootcmd 'nand read 0x22000000 0x00360000 0x00280000; run _mtd; bootm' saveenv note: setenv your ubi.mtd might be different depending on kernel version.