diff options
Diffstat (limited to 'src/northbridge/amd/amdk8/amdk8_acpi.c')
| -rw-r--r-- | src/northbridge/amd/amdk8/amdk8_acpi.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/northbridge/amd/amdk8/amdk8_acpi.c b/src/northbridge/amd/amdk8/amdk8_acpi.c index 712315ee09..c3f0f07d23 100644 --- a/src/northbridge/amd/amdk8/amdk8_acpi.c +++ b/src/northbridge/amd/amdk8/amdk8_acpi.c @@ -270,7 +270,15 @@ int k8acpi_write_vars(void) msr = rdmsr(TOP_MEM); lens += acpigen_write_name_dword("TOM1", msr.lo); msr = rdmsr(TOP_MEM2); - lens += acpigen_write_name_qword("TOM2", (((uint64_t) msr.hi) << 32) | msr.lo); + /* + * Since XP only implements parts of ACPI 2.0, we can't use a qword + * here. + * See http://www.acpi.info/presentations/S01USMOBS169_OS%2520new.ppt + * slide 22ff. + * Shift value right by 20 bit to make it fit into 32bit, + * giving us 1MB granularity and a limit of almost 4Exabyte of memory. + */ + lens += acpigen_write_name_dword("TOM2", (msr.hi << 12) | msr.lo >> 20); lens += k8acpi_write_HT(); //minus opcode |