R220 memory lost in 32-bit Debian 6.0.9

Hi all,

After applying the "acpi=off" trick to my 32-bit Debian 6.0.9, the R220 boots up.

The total memory shown in /proc/meminfo and the "free" command is 2.4G. In the old R210 platform it is 3.1G. In memory addresses shown in dmesg for R220:

[    0.000000] Linux version 3.0.23-1-586-vyatta (root@builder-12.102) (gcc version 4.4.5 (Debian 4.4.5-8) ) #1 SMP Sun Jan 27 23:37:33 PST 2013
[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
[    0.000000]  BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
[    0.000000]  BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
[    0.000000]  BIOS-e820: 0000000000100000 - 000000009573f000 (usable)
[    0.000000]  BIOS-e820: 000000009573f000 - 0000000095bbf000 (reserved)
[    0.000000]  BIOS-e820: 0000000095bbf000 - 0000000095fbf000 (ACPI NVS)
[    0.000000]  BIOS-e820: 0000000095fbf000 - 0000000095fff000 (ACPI data)
[    0.000000]  BIOS-e820: 0000000095fff000 - 0000000096000000 (usable)
[    0.000000]  BIOS-e820: 0000000096000000 - 00000000a0000000 (reserved)
[    0.000000]  BIOS-e820: 00000000f0000000 - 00000000f8000000 (reserved)
[    0.000000]  BIOS-e820: 00000000feb00000 - 00000000feb04000 (reserved)
[    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed10000 - 00000000fed1a000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed1c000 - 00000000fed20000 (reserved)
[    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  BIOS-e820: 00000000ffa00000 - 0000000100000000 (reserved)
[    0.000000]  BIOS-e820: 0000000100000000 - 0000000260000000 (usable)

0x96000000 is 2.5G. So that explains the 2.4G total memory reported in /proc/meminfo.

Looks like there is 5.9G of usable memory in the range 0x100000000 to 0x260000000.

But my OS is 32-bit and my kernel probably does not have PAE enabled. Found a article about this subject. The poster said that in BIOS there is a north bridge option to remap memory hole. But I can't find such in the BIOS version 1.2.1 (the latest).

Any one knows how to reclaim the lost memory? Could this memory lost be a contributing factor to 32-bit OS won't boot in R220? Cause the kernel panic mentions unable to access memory page (see

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1329384).

Thanks in advance for any suggestions.

sialnije