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
https://openbios.org/roundup/linuxbios/issue55
This patch is a little bit enhanced, it keeps the ppc table consistent,
which Yinghai's original patch did not.
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2342 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
will generate the struct lb_memory_range the same.
- Add a few pci_ids.
- Small readabiltiy clean ups to debug_dev
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1818 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
- The sandpointx3+altimus has been consolidated into one directory for now.
- Added support for having different versions of the pci access functions
on a per bus basis if needed.
Hopefully I have not broken something inadvertently.
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1786 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
ram linuxbios_ram instead of linuxbios_c and linuxbios_payload...
- Reordered the linker sections so the LinuxBIOS fallback image can take more the 64KiB on x86
- ROM_IMAGE_SIZE now will work when it is specified as larger than 64KiB.
- Tweaked the reset16.inc and reset16.lds to move the sanity check to see if everything will work.
- Start using romcc's built in preprocessor (This will simplify header compiler checks)
- Add helper functions for examining all of the resources
- Remove debug strings from chip.h
- Add llshell to src/arch/i386/llshell (Sometime later I can try it...)
- Add the ability to catch exceptions on x86
- Add gdb_stub support to x86
- Removed old cpu options
- Added an option so we can detect movnti support
- Remove some duplicate definitions from pci_ids.h
- Remove the 64bit resource code in amdk8/northbridge.c in preparation for making it generic
- Minor romcc bug fixes
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1727 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
- mem.h and sizeram.h and all includes killed because the are no longer needed.
- linuxbios_table.c updated to directly look at the device tree for occupied memory areas.
- first very incomplete stab a converting the ppc code to work with the dynamic device tree
- Ignore resources before we have read them from devices, (if the device is disabled ignore it's resources).
- First stab at Pentium-M support
- add part/init_timer.h making init_timer conditional until there is a better way of handling it.
- Converted all of the x86 sizeram to northbridge set_resources functions.
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1722 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Roman Kononov