diff options
| author | Roman Kononov <kononov195-lbl@yahoo.com> | 2007-02-01 00:44:27 +0000 |
|---|---|---|
| committer | Stefan Reinauer <stepan@openbios.org> | 2007-02-01 00:44:27 +0000 |
| commit | 57e700f4f467afdad89e75820a7fae47f6b8b7ae (patch) | |
| tree | 1d4f7892ff8e90ef625a7ff3c1bdfe5e30889985 /src/arch | |
| parent | 0980049a629acea1c069f19bede02b5d5a2feab7 (diff) | |
great check-in message:
Linuxbios boots an Opteron motherboard with 1GB memory.
Linuxbios directly loads a recent linux kernel.
The memory layout is like this:
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 0000000000000e18 (reserved)
BIOS-e820: 0000000000000e18 - 00000000000a0000 (usable)
BIOS-e820: 00000000000c0000 - 00000000000f0000 (usable)
BIOS-e820: 00000000000f0000 - 00000000000f0400 (reserved)
BIOS-e820: 00000000000f0400 - 0000000040000000 (usable)
The f0000-f0400 region contains IRQ and ACPI tables.
At some point the kernel builds a resource table containing
all physical address ranges and type of hardware the addresses
are mapped to. The table is accessible via /proc/iomem:
# cat /proc/iomem
00000000-00000e17 : reserved
00000e18-0009ffff : System RAM
000a0000-000bffff : Video RAM area
000c0000-000cbfff : Video ROM
000f0000-000fffff : System ROM
e0000000-efffffff : PCI Bus #03
e0000000-efffffff : 0000:03:00.0
f0000000-f3ffffff : GART
f4000000-f60fffff : PCI Bus #03
f4000000-f4ffffff : 0000:03:00.0
f5000000-f5ffffff : 0000:03:00.0
f6000000-f601ffff : 0000:03:00.0
f6100000-f6100fff : 0000:00:01.0
f6101000-f6101fff : 0000:00:02.0
f6101000-f6101fff : ohci_hcd
f6102000-f6102fff : 0000:00:04.0
f6103000-f6103fff : 0000:00:07.0
f6103000-f6103fff : sata_nv
f6104000-f6104fff : 0000:00:08.0
f6104000-f6104fff : sata_nv
f6105000-f6105fff : 0000:00:0a.0
f6106000-f61060ff : 0000:00:02.1
f6200000-f620ffff : 0000:40:01.0
As you can see, the 00000000000f0400-0000000040000000
region is not listed.
It is not listed because the kernel unconditionally adds
"000f0000-000fffff : System ROM" first (look for
"request_resource(&iomem_resource, &system_rom_resource)"),
and then the attempt to add f0400-40000000 range fails
because of overlapping.
The kernel does not care that the range is not listed there.
Kexec does. It uses the /proc/iomem file to instruct the
kexec system call how to place the segments of a new kernel
in the physical memory. Kexec fails to start a new kernel
because it cannot locate enough physical memory.
This must be fixed either in linux or linuxbios.
Assuming that linuxbios is to be fixed, I cooked a patch
which provides this memory layout:
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 0000000000000e18 (reserved)
BIOS-e820: 0000000000000e18 - 00000000000a0000 (usable)
BIOS-e820: 00000000000c0000 - 00000000000f0000 (usable)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 0000000040000000 (usable)
The /proc/iomem contains:
# cat /proc/iomem
00000000-00000e17 : reserved
00000e18-0009ffff : System RAM
000a0000-000bffff : Video RAM area
000c0000-000cbfff : Video ROM
000f0000-000fffff : System ROM
00100000-3fffffff : System RAM
00100000-00203c61 : Kernel code
00203c62-00248c3f : Kernel data
e0000000-efffffff : PCI Bus #03
e0000000-efffffff : 0000:03:00.0
f0000000-f3ffffff : GART
f4000000-f60fffff : PCI Bus #03
f4000000-f4ffffff : 0000:03:00.0
f5000000-f5ffffff : 0000:03:00.0
f6000000-f601ffff : 0000:03:00.0
f6100000-f6100fff : 0000:00:01.0
f6101000-f6101fff : 0000:00:02.0
f6101000-f6101fff : ohci_hcd
f6102000-f6102fff : 0000:00:04.0
f6103000-f6103fff : 0000:00:07.0
f6103000-f6103fff : sata_nv
f6104000-f6104fff : 0000:00:08.0
f6104000-f6104fff : sata_nv
f6105000-f6105fff : 0000:00:0a.0
f6106000-f61060ff : 0000:00:02.1
f6200000-f620ffff : 0000:40:01.0
Kexec is happier with the patch.
Regards,
Signed-off-by: Roman Kononov <kononov195-lbl@yahoo.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2542 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/i386/boot/linuxbios_table.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/arch/i386/boot/linuxbios_table.c b/src/arch/i386/boot/linuxbios_table.c index 402f7f90e0..f1be49bbc6 100644 --- a/src/arch/i386/boot/linuxbios_table.c +++ b/src/arch/i386/boot/linuxbios_table.c @@ -382,8 +382,9 @@ unsigned long write_linuxbios_table( low_table_start, low_table_end - low_table_start); /* Record the pirq table, acpi tables, and maybe the mptable */ + table_size=rom_table_end-rom_table_start; lb_add_memory_range(mem, LB_MEM_TABLE, - rom_table_start, rom_table_end - rom_table_start); + rom_table_start, table_size<0x10000?0x10000:table_size); /* Note: * I assume that there is always memory at immediately after |