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| author | Patrick Rudolph <patrick.rudolph@9elements.com> | 2020-05-01 18:35:36 +0200 |
|---|---|---|
| committer | Angel Pons <th3fanbus@gmail.com> | 2020-08-11 12:03:09 +0000 |
| commit | 4e0cd82b5b96ac729654a19eff445b0b4cc10350 (patch) | |
| tree | 7bc244a6a9295207b41c76908512727390b0348e | |
| parent | b5fa9c8200423beb660403b6656fa8fd5d7edc31 (diff) | |
| download | coreboot-4e0cd82b5b96ac729654a19eff445b0b4cc10350.tar.xz | |
nb/intel/sandybridge/raminit: Add comments
Add comments found when testing ECC scrubbing code.
This is a cosmetic change.
Change-Id: I7975f6070c2002930eec407a6b101a1295495b25
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40947
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
| -rw-r--r-- | src/northbridge/intel/sandybridge/raminit_common.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/northbridge/intel/sandybridge/raminit_common.c b/src/northbridge/intel/sandybridge/raminit_common.c index 126acbe65e..3527c8e520 100644 --- a/src/northbridge/intel/sandybridge/raminit_common.c +++ b/src/northbridge/intel/sandybridge/raminit_common.c @@ -319,8 +319,14 @@ void dram_dimm_mapping(ramctr_timing *ctrl) reg |= (dimmB->width / 8 - 1) << 20; } - reg |= 1 << 21; /* Rank interleave */ - reg |= 1 << 22; /* Enhanced interleave */ + /* + * Rank interleave: Bit 16 of the physical address space sets + * the rank to use in a dual single rank DIMM configuration. + * That results in every 64KiB being interleaved between two ranks. + */ + reg |= 1 << 21; + /* Enhanced interleave */ + reg |= 1 << 22; if ((dimmA && (dimmA->ranks > 0)) || (dimmB && (dimmB->ranks > 0))) { ctrl->mad_dimm[channel] = reg; |