Ok, thanks all for dumps!

Results:

* All dumps with revision 2101 are same.
* All dumps with revision 2204 are same.

I do not need more 2101 and 2204 dumps. But I have only one dump for revision 2104. Please if somebody has N900 with other hw revision (not 2101 and 2204), please attach dump.

OMAP tabe is same for all dumps (2101, 2204 and 2104) (differences in hw-build and bootreason I'm ignoring for obvious reason). So I think this OMAP table can be hardcoded into U-Boot.

But there is one big difference between 2101 and others (2104, 2204).

2101 has two MEM tags:
ATAG MEM size=08000000 start=80000000
ATAG MEM size=08000000 start=88000000

but 2104 and 2204 only one:
ATAG MEM size=10000000 start=80000000

total size of RAM is same, but I have no idea why 2101 has it devided...

And I checked RX-51 fiasco firmware and X-Loader and NOLO images are same for all 21** and 22** revisions. No idea how can NOLO detect correct revision and pass different MEM atags...