[U-Boot] Loading a userland file

[Grant]

> I'm trying to get Tiny Core working on the Beaglebone.  I'm stuck on
getting the Tiny Core userland file "uCore" to load so init works.  I'm
using this uEnv.txt:
>
> bootfile=/uImage
> optargs=init=/init rootwait
> fatload mmc 0 0x43100000 uCore
> mmcboot=echo Booting from mmc ...; run mmcargs; bootm 0x80200000
0x43100000
>
> I get the following "data abort":
>
> ## Booting kernel from Legacy Image at 80200000 ...
> Image Name:   Linux-3.6.0-rc7-00219-g35e0f42
> Image Type:   ARM Linux Kernel Image (uncompressed)
> Data Size:    2878667 Bytes = 2.7 MiB
> Load Address: 80008000
> Entry Point:  80008000
> Verifying Checksum ... OK
> data abort
> pc : [<8ff99480>]          lr : [<8ff996ac>]
> sp : 8fe6abd0  ip : 8fe6d163     fp : 00000001
> r10: 00000002  r9 : 00000000     r8 : 8fe6af68
> r7 : 8ffbaebc  r6 : 43100000     r5 : 8ffbaec0  r4 : 43100000
> r3 : 00000000  r2 : 00000010     r1 : 00000000  r0 : 43100000
> Flags: nZCv  IRQs off  FIQs on  Mode SVC_32
> Resetting CPU ...
>
> If I change mmcboot to:
>
> mmcboot=echo Booting from mmc ...; run mmcargs; bootm 0x80200000
>
> The kernel loads, but init fails:
>
> EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts:
(null)
> VFS: Mounted root (ext4 filesystem) readonly on device 179:2.
> devtmpfs: error mounting -2
> Freeing init memory: 144K
> Failed to execute /init.  Attempting defaults...
> Kernel panic - not syncing: No init found.  Try passing init= option to
kernel.
>
> Can anyone tell me how to load uCore so init works?
>
> - Grant

I've gotten farther along, but I get one of these two errors when loading
the ramdisk:

RAMDISK: Couldn't find valid RAM disk image starting at 0.

Wrong Ramdisk Image Format
Ramdisk image is corrupt or invalid

Please let me know if you have any pointers.

- Grant