[coreboot] WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 2MB of RAM

Joseph Smith joe at settoplinux.org
Sat Jun 12 16:05:56 CEST 2010


Hello,
While working on my i810 port I am getting this message from the Linux 
kernel about my mtrr setup:

BIOS-provided physical RAM map:
  BIOS-e820: 0000000000000000 - 0000000000001000 type 16
  BIOS-e820: 0000000000001000 - 00000000000a0000 (usable)
  BIOS-e820: 00000000000c0000 - 000000000fef0000 (usable)
  BIOS-e820: 000000000fef0000 - 000000000ff00000 type 16
DMI not present or invalid.
last_pfn = 0xfef0 max_arch_pfn = 0x100000
WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 2MB of RAM.
------------[ cut here ]------------
WARNING: at arch/x86/kernel/cpu/mtrr/main.c:1557 
mtrr_trim_uncached_memory+0x295/0x2b6() (Not tainted)
Modules linked in:
Pid: 0, comm: swapper Not tainted 2.6.27.24-170.2.68.fc10.i686 #1
  [<c042ddfb>] warn_on_slowpath+0x65/0x8b
  [<c06ab53c>] ? _spin_unlock_irqrestore+0x1b/0x38
  [<c06ab53c>] ? _spin_unlock_irqrestore+0x1b/0x38
  [<c06ab543>] ? _spin_unlock_irqrestore+0x22/0x38
  [<c042e2f1>] ? release_console_sem+0x1bf/0x1c7
  [<c042e76c>] ? vprintk+0x2ce/0x2f3
  [<c06a96db>] ? printk+0xf/0x14
  [<c0824127>] mtrr_trim_uncached_memory+0x295/0x2b6
  [<c081f73b>] setup_arch+0x48f/0x947
  [<c042e76c>] ? vprintk+0x2ce/0x2f3
  [<c08218dd>] ? __reserve_early+0xe4/0xf8
  [<c06a96db>] ? printk+0xf/0x14
  [<c0819605>] start_kernel+0x73/0x2f0
  [<c0819080>] __init_begin+0x80/0x88
  =======================
---[ end trace 4eaa2a86a8e2da22 ]---
update e820 for mtrr
modified physical RAM map:
  modified: 0000000000000000 - 0000000000001000 type 16
  modified: 0000000000001000 - 00000000000a0000 (usable)
  modified: 00000000000c0000 - 000000000fc00000 (usable)
  modified: 000000000fc00000 - 000000000fef0000 (reserved)
  modified: 000000000fef0000 - 000000000ff00000 type 16
last_pfn = 0xfc00 max_arch_pfn = 0x100000

----------------------------------------------

Any ideas? Full bootlog attached.

-- 
Thanks,
Joseph Smith
Set-Top-Linux
www.settoplinux.org
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: i810_boot_test8.txt
URL: <http://www.coreboot.org/pipermail/coreboot/attachments/20100612/a59082d6/attachment.txt>


More information about the coreboot mailing list