diff options
Diffstat (limited to 'src/northbridge/intel/i945/ram_calc.c')
| -rw-r--r-- | src/northbridge/intel/i945/ram_calc.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/src/northbridge/intel/i945/ram_calc.c b/src/northbridge/intel/i945/ram_calc.c index a106d117f2..15ba7f4527 100644 --- a/src/northbridge/intel/i945/ram_calc.c +++ b/src/northbridge/intel/i945/ram_calc.c @@ -25,6 +25,24 @@ #include <cpu/x86/mtrr.h> #include <program_loading.h> +/* Decodes TSEG region size to bytes. */ +u32 decode_tseg_size(const u8 esmramc) +{ + if (!(esmramc & 1)) + return 0; + switch ((esmramc >> 1) & 3) { + case 0: + return 1 << 20; + case 1: + return 2 << 20; + case 2: + return 8 << 20; + case 3: + default: + die("Bad TSEG setting.\n"); + } +} + static uintptr_t smm_region_start(void) { uintptr_t tom; @@ -35,24 +53,8 @@ static uintptr_t smm_region_start(void) else tom = (pci_read_config8(PCI_DEV(0, 0, 0), TOLUD) & 0xf7) << 24; - /* if TSEG enabled subtract size */ - switch (pci_read_config8(PCI_DEV(0, 0, 0), ESMRAMC) & 0x07) { - case 0x01: - /* 1MB TSEG */ - tom -= 0x100000; - break; - case 0x03: - /* 2MB TSEG */ - tom -= 0x200000; - break; - case 0x05: - /* 8MB TSEG */ - tom -= 0x800000; - break; - default: - /* TSEG either disabled or invalid */ - break; - } + /* subsctract TSEG size */ + tom -= decode_tseg_size(pci_read_config8(PCI_DEV(0, 0, 0), ESMRAMC)); return tom; } |