Mike Loptien (mike.loptien@se-eng.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/5977
-gerrit
commit a6ac2f6dd039e119e9b7124d3ccfcc7ebe6bb787 Author: Mike Loptien mike.loptien@se-eng.com Date: Wed Jun 11 14:20:48 2014 -0600
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 --- src/arch/x86/boot/mpspec.c | 2 +- src/arch/x86/include/arch/smp/mpspec.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/arch/x86/boot/mpspec.c b/src/arch/x86/boot/mpspec.c index e66535a..cd2b142 100644 --- a/src/arch/x86/boot/mpspec.c +++ b/src/arch/x86/boot/mpspec.c @@ -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; diff --git a/src/arch/x86/include/arch/smp/mpspec.h b/src/arch/x86/include/arch/smp/mpspec.h index fe3ce68..725718a 100644 --- a/src/arch/x86/include/arch/smp/mpspec.h +++ b/src/arch/x86/include/arch/smp/mpspec.h @@ -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) */