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MP Spec: Correct the Virtual Wire assignment 

Virtual Wire mode is set by writing 0 to the the MPTable
Feature2 bit field 'IMCR'.  The virtualwire variable was
initially defined as writing a 1 to this bit field which
would actually set PIC mode instead of Virtual Wire mode.
However, nearly every mainboard called the MPTables with
virtualwire = 0, which actually had the effect of setting
Virtual Wire mode. I am correcting the definition but
leaving the call to write the MPTables with virtualwire = 0,
which is how most mainboards are already setting the tables
up.

See the MP Spec table 4-1 for more details:
	Bit 7: IMCRP. When the IMCR presence bit is
	set, the IMCR is present and PIC Mode is
	implemented; otherwise, Virtual Wire Mode is
	implemented.

http://download.intel.com/design/archives/processors/pro/docs/24201606.pdf

Change-Id: I039d88134aabd55166c2b68aa842bacbfcc0f42b
Signed-off-by: Mike Loptien <mike.loptien@se-eng.com>
Reviewed-on: http://review.coreboot.org/5977
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
This commit is contained in:
Mike Loptien 2014-06-11 14:20:48 -06:00
parent 9159734065
commit d0167d3ae2
2 changed files with 3 additions and 3 deletions
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2
src/arch/x86/boot/mpspec.c
View File

@ -89,7 +89,7 @@ static void *smp_write_floating_table_physaddr(unsigned long addr, unsigned long
mf->mpf_specification = 4;
mf->mpf_checksum = 0;
mf->mpf_feature1 = 0;
mf->mpf_feature2 = virtualwire?MP_FEATURE_VIRTUALWIRE:0;
mf->mpf_feature2 = virtualwire?MP_FEATURE_PIC:MP_FEATURE_VIRTUALWIRE;
mf->mpf_feature3 = 0;
mf->mpf_feature4 = 0;
mf->mpf_feature5 = 0;

4
src/arch/x86/include/arch/smp/mpspec.h
View File

@ -52,8 +52,8 @@ struct intel_mp_floating
unsigned char mpf_checksum; /* Checksum (makes sum 0) */
unsigned char mpf_feature1; /* Standard or configuration ? */
unsigned char mpf_feature2; /* Bit7 set for IMCR|PIC */
#define MP_FEATURE_VIRTUALWIRE (1 << 7)
#define MP_FEATURE_PIC (0 << 7)
#define MP_FEATURE_VIRTUALWIRE (0 << 7)
#define MP_FEATURE_PIC (1 << 7)
unsigned char mpf_feature3; /* Unused (0) */
unsigned char mpf_feature4; /* Unused (0) */
unsigned char mpf_feature5; /* Unused (0) */