[PATCH 1/3] Update BIOS INT15-E820 to allow a larger BIOS image

Jordan Justen
2009-07-27T00:23:53Z

The bios will now reserve more memory via the E820 functions.

Note that the standard KVM BIOS will most likely not make use of
this expanded BIOS region. This change will synchronize
the BIOS INT15-E820 reservations to match other changes that
will allow alternate BIOS images to be larger in size.

Previously the BIOS reserved:
0xfffbc000-0xfffbcfff - 4KB - EPT identity mapping pages
0xfffbd000-0xfffbffff - 12KB - TSS pages
0xfffc0000-0xffffffff - 256KB - Max bios.bin (usually top 128KB is used)

Now the BIOS will reserve:
0xfeffc000-0xfeffcfff - 4KB - EPT identity mapping pages
0xfeffd000-0xfeffffff - 12KB - TSS Pages
0xff000000-0xffffffff - 16MB - Max bios.bin

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
---
kvm/bios/rombios.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kvm/bios/rombios.c b/kvm/bios/rombios.c
index 6186199..2d0c153 100644
--- a/kvm/bios/rombios.c
+++ b/kvm/bios/rombios.c
@@ -4596,14 +4596,14 @@ ASM_END
case 5:
/* 4 pages before the bios, 3 pages for vmx tss pages,
* the other page for EPT real mode pagetable */
- set_e820_range(ES, regs.u.r16.di, 0xfffbc000L,
- 0xfffc0000L, 0, 0, 2);
+ set_e820_range(ES, regs.u.r16.di, 0xfeffc000L,
+ 0xff000000L, 0, 0, 2);
regs.u.r32.ebx = 6;
break;
case 6:
- /* 256KB BIOS area at the end of 4 GB */
+ /* 16MB BIOS area at the end of 4 GB */
set_e820_range(ES, regs.u.r16.di,
- 0xfffc0000L, 0x00000000L ,0, 0, 2);
+ 0xff000000L, 0x00000000L ,0, 0, 2);
if (extra_highbits_memory_size || extra_lowbits_memory_size)
regs.u.r32.ebx = 7;
else
--
1.6.0.4