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

[Magnus Christensson <mch@virtutech.com>]

On 12/13/2009 04:14 PM, Kevin O'Connor wrote:
> ----- Forwarded message from Gleb Natapov<gleb@redhat.com>  -----
>
> From: Gleb Natapov<gleb@redhat.com>
> To: Kevin O'Connor<kevin@koconnor.net>
> Date: Sun, 13 Dec 2009 15:18:08 +0200
> Subject: Re: [mch@virtutech.com: [coreboot] [PATCH] Seabios: Fix PkgLength
> 	calculation for the SSDT.]
>
> On Thu, Dec 10, 2009 at 08:55:30AM -0500, Kevin O'Connor wrote:
>    
>> FYI.
>>
>> ----- Forwarded message from Magnus Christensson<mch@virtutech.com>  -----
>>
>> From: Magnus Christensson<mch@virtutech.com>
>> To: coreboot@coreboot.org
>> Date: Thu, 26 Nov 2009 13:22:14 +0100
>> Subject: [coreboot] [PATCH] Seabios: Fix PkgLength calculation for the SSDT.
>>
>> See attached patch.
>>
>> M.
>>
>>
>> > From d9dc0f50b2ce756e8a3b4ede0a8ecbe76f2afcb8 Mon Sep 17 00:00:00 2001
>> From: Magnus Christensson<mch@virtutech.com>
>> Date: Wed, 25 Nov 2009 16:26:58 +0100
>> Subject: [PATCH 13/13] Fix PkgLength calculation for the SSDT.
>>
>> Signed-off-by: Magnus Christensson<mch@virtutech.com>
>> ---
>>   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.

M.