[U-Boot-Users] best way to debug memory address problems?

[Alan Bennett]

Help;  I'm trying to figure out if these errors are hardware or
software.  And of course, this is our first ppc/uboot system, so I'm
still stepping through a lot of learning as I go.

I'm supposed to have a memory region from 0 to 7fff_ffff assigned to
our 128MB memory.  However, I run into several issues when trying to
run mtest.  I end up with an large sections  mis-behaving.  I don't
see any conflicts in the BRx registers, and I believe my OR1 is set up
properly, so I'm not sure how to proceed.

good:
#> md  0x00100000 1; mw  0x00100000 0xfff0000f ; md  0x00100000 1;
00100000: ffffffff    ....
00100000: fff0000f    ....

bad:
#> md  0x00b8ac98 1; mw  0x00b8ac98 0xffff0000 ; md  0x00b8ac98 1;
00b8ac98: 61633938    ac98
00b8ac98: 61633938    ac98
#> md  0x00b8ac98 1; mw  0x00b8ac98 0x0000ffff ; md  0x00b8ac98 1;
00b8ac98: 61633938    ac98
00b8ac98: 61633938    ac98
#> md  0x00b8ac98 1; mw  0x00b8ac98 0xff0000ff ; md  0x00b8ac98 1;
00b8ac98: 61633938    ac98
00b8ac98: 61633938    ac98

System: mpc8248 - custom board based on ep8248e
128 MB RAM; 128 MB Flash; 128 MB Flash
#> memcinfo
BR0   = f8001801 OR0   = f80018c2
BR1   = 00001841 OR1   = f8002b00
BR2   = f4000801 OR2   = fff018c4
BR3   = 00000000 OR3   = 00000000
BR4   = e8001801 OR4   = f80018c2
BR5   = f4100801 OR5   = fff00864
BR6   = f4200801 OR6   = fff00864
BR7   = 00000000 OR7   = 00000000
BR8   = 00000000 OR8   = 00000000
BR9   = 00000000 OR9   = 00000000
BR10  = 00000000 OR10  = 00000000
BR11  = 00000000 OR11  = 00000000
MAR   = adf32865
MAMR  = 00000000 MBMR  = 00000000 MCMR  = 00000000
MPTPR =     1300 MDR   = 1d005815
PSDMR = c2672522 LSDMR = 00000000
PURT  =       21 PSRT  =       4b
LURT  =       12 LSRT  =       a9
IMMR  = f0000c10