Roberto Guerra wrote:

mtdparts=phys:1600K(ROM)ro,6M(root),512K(U-Boot)ro,512K(unused)
rootfstype=jffs2
=> bootm 200000 - 400000
<snip>
physmap platform flash device: 00800000 at ff800000
physmap-flash.0: Found 1 x16 devices at 0x0 in 16-bit bank
 Amd/Fujitsu Extended Query Table at 0x0040
physmap-flash.0: CFI does not contain boot bank location. Assuming
top.

Hmm, you seem to be using physmap rather than physmap_of -- so it won't 
even be looking at your device tree node.

List of all partitions:
0100       4096 ram0 (driver?)
0101       4096 ram1 (driver?)
0102       4096 ram2 (driver?)
0103       4096 ram3 (driver?)
0104       4096 ram4 (driver?)
0105       4096 ram5 (driver?)
0106       4096 ram6 (driver?)
0107       4096 ram7 (driver?)
0108       4096 ram8 (driver?)
0109       4096 ram9 (driver?)
010a       4096 ram10 (driver?)
010b       4096 ram11 (driver?)
010c       4096 ram12 (driver?)
010d       4096 ram13 (driver?)
010e       4096 ram14 (driver?)
010f       4096 ram15 (driver?)

Where are all these coming from?

The key change in my kernel config was the BIG_ENDIAN=Y.
The kernel probes the AMD chip, but it can't see the partitions.

Even without partiitons, you should see the whole flash device...

I guess now I will have to define my mtd partitions in either FDT or
in the kernel arguments.
Which is the best way to define them?

If you're defining a standard layout for the platform that's unlikely to 
change, I'd go with the device tree.  Otherwise, I'd go with whatever's 
most convenient.

If the partitions are defined in
both FDT and bootargs, which one takes precedence?

The command line takes precedence.

-Scott