I took the self compiled HEAD image which runs on my Philips 2xI, swapped out u-boot-2xI against a uboot-1xI, bootlog shows:
...
Options:
1: console on ttyS0
2: console on fb0
3: console on null
Select option (1-3), other keys to stop autoboot: 0
..............................................................
Un-Protected 62 sectors
### FS (jffs2) loading 'vmlinuz' to 0x100000
Scanning JFFS2 FS:

find_inode failed for name=vmlinuz
load: Failed to find inode
### FS LOAD ERROR<0> for vmlinuz!
## Booting image at 00100000 ...
Bad Magic Number
=>
Is there more to do than just u-boot for a 1xI box?
JockyW