Re: Re: [PATCH 0/5] bios: >4G updates

[Alex Williamson <alex.williamson@hp.com>]

On Sun, 2008-10-12 at 18:50 -0400, Kevin O'Connor wrote:
> As an aside, is there any interest in using SeaBIOS with kvm?
> 
> SeaBIOS is a port of bochs bios to gcc.  I've been using SeaBIOS
> (along with coreboot) to boot and provide bios functions on real
> hardware.  It works fine under qemu also.

Sounds interesting to me.  The VirtaulBox project has also made
improvements to the bochs bios that might be nice to pull in.  I'd also
like to see the TianoCore EFI image, that ia64 is using, work on x86.
There's an x86 version for QEMU on the QEMU downloads page.  With the
(wip) patch below to increase the bios reserved region to 1MB I can boot
to the EFI shell, but KVM is missing some emulation to boot Linux (works
with --no-kvm, maybe an ff 6f opcode?).  I haven't had a chance to debug
it further.  Thanks,

Alex

Increase BIOS memory region to 1MB

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
--

diff --git a/bios/rombios.c b/bios/rombios.c
index 818ce63..57e5139 100644
--- a/bios/rombios.c
+++ b/bios/rombios.c
@@ -4579,17 +4579,17 @@ ASM_END
                         break;
                     case 5:
                         /* 3 pages before the bios, we map the vmx tss pages */
-                        set_e820_range(ES, regs.u.r16.di, 0xfffbd000L,
-                                       0xfffc0000L, 0, 0, 2);
+                        set_e820_range(ES, regs.u.r16.di, 0xffdfd000L,
+                                       0xffe00000L, 0, 0, 2);
                         regs.u.r32.ebx = 6;
                         regs.u.r32.eax = 0x534D4150;
                         regs.u.r32.ecx = 0x14;
                         CLEAR_CF();
                          return;
                     case 6:
-                        /* 256KB BIOS area at the end of 4 GB */
+                        /* 1MB BIOS area at the end of 4 GB */
                         set_e820_range(ES, regs.u.r16.di,
-                                       0xfffc0000L, 0x00000000L ,0, 0, 2);
+                                       0xffe00000L, 0x00000000L ,0, 0, 2);
                         if (extra_highbits_memory_size || extra_lowbits_memory_size)
                             regs.u.r32.ebx = 7;
                         else
diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
index a8cca15..d9850a4 100644
--- a/libkvm/libkvm-x86.c
+++ b/libkvm/libkvm-x86.c
@@ -42,7 +42,7 @@ static int kvm_init_tss(kvm_context_t kvm)
 		 * this address is 3 pages before the bios, and the bios should present
 		 * as unavaible memory
 		 */
-		r = kvm_set_tss_addr(kvm, 0xfffbd000);
+		r = kvm_set_tss_addr(kvm, 0xffdfd000);
 		if (r < 0) {
 			fprintf(stderr, "kvm_init_tss: unable to set tss addr\n");
 			return r;



-- 
Alex Williamson                             HP Open Source & Linux Org.