just wanted to post this here to point out how i got this working.
when stopping uboot i couldnt quite follow the procedure at
http://plugcomputer.org/plugwiki/index.php/SD_Card_As_Root_File_System , it would say that it couldnt find the environment variable bootargs, however there was an argument which WAS promising:
printenv bootargs_root
bootargs_root=ubi.mtd=1 root=ubi0:rootfs rootfstype=ubifs
with this i tried
setenv bootargs_root root=/dev/mmcblk0p1
boot
unfortunately it did not work, and i got the error message:
FS: Unable to mount root fs via NFS, trying floppy.
VFS: Cannot open root device "mmcblk0p1=rw,relatime" or unknown-block(2,0)
Please append a correct "root=" boot option; here are the available partitions:
1f00 4096 mtdblock0 (driver?)
1f01 519168 mtdblock1 (driver?)
b300 7974912 mmcblk0 driver: mmcblk
b301 7973824 mmcblk0p1
after messing around with it some, this does work:
setenv bootargs_root root=b301
boot
i tested it out and then did the setenv command followed by a saveenv command and it persisted through reboot. here is a comparison of the file system before and after- it seems to be working properly. for the moment at least....
before:
df
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 256904 0 256904 0% /lib/init/rw
varrun 256904 36 256868 1% /var/run
varlock 256904 0 256904 0% /var/lock
udev 256904 112 256792 1% /dev
tmpfs 256904 0 256904 0% /dev/shm
rootfs 471428 184848 281744 40% /
mount
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
rootfs on / type rootfs (rw)
after:
df
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 256904 0 256904 0% /lib/init/rw
varrun 256904 36 256868 1% /var/run
varlock 256904 0 256904 0% /var/lock
udev 256904 112 256792 1% /dev
tmpfs 256904 0 256904 0% /dev/shm
rootfs 7848580 449400 7000492 7% /
mount
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
rootfs on / type rootfs (rw)
hope that is helpful if someone else is trying to do this... i updated the wiki with this information
http://plugcomputer.org/plugwiki/index.php/SD_Card_As_Root_File_System#Write_u-boot_environment_to_flash_if_desired.