[Qemu-devel] Re: [PATCH] Seabios: Fix PkgLength calculation for the SSDT.

[Gleb Natapov]

On Mon, Dec 14, 2009 at 10:25:14AM +0100, Magnus Christensson wrote:
> >>> From d9dc0f50b2ce756e8a3b4ede0a8ecbe76f2afcb8 Mon Sep 17 00:00:00 2001
> >>From: Magnus Christensson<address@hidden>
> >>Date: Wed, 25 Nov 2009 16:26:58 +0100
> >>Subject: [PATCH 13/13] Fix PkgLength calculation for the SSDT.
> >>
> >>Signed-off-by: Magnus Christensson<address@hidden>
> >>---
> >>  src/acpi.c |    6 ++++--
> >>  1 files changed, 4 insertions(+), 2 deletions(-)
> >>
> >>diff --git a/src/acpi.c b/src/acpi.c
> >>index 843af69..88007ae 100644
> >>--- a/src/acpi.c
> >>+++ b/src/acpi.c
> >>@@ -464,10 +464,12 @@ build_ssdt(void)
> >>      // build processor scope header
> >>      *(ssdt_ptr++) = 0x10; // ScopeOp
> >>      if (cpu_length<= 0x3e) {
> >>+        /* Handle 1-4 CPUs with one byte encoding */
> >>          *(ssdt_ptr++) = cpu_length + 1;
> >>      } else {
> >>-        *(ssdt_ptr++) = 0x7F;
> >>-        *(ssdt_ptr++) = (cpu_length + 2)>>  6;
> >>+        /* Handle 5-314 CPUs with two byte encoding */
> >>+        *(ssdt_ptr++) = 0x40 | ((cpu_length + 1)&  0xf);
> >>+        *(ssdt_ptr++) = (cpu_length + 1)>>  4;
> >Should be cpu_length + 2 as far as I can tell. The current code is
> >definitely broken.
> Right. That should be cpu_length +2 in the else-part.
> 
BTW, how did you notice it? What OS fails?

--
                        Gleb.