nb/intel/sandybridge/raminit: Add XMP support
Some vendors store lower frequency profiles in the regular SPD,
if the SPD contains a XMP profile. To make use of the board's and DIMM's
maximum supported DRAM frequency, try to parse the XMP profile and
use it instead.
Validate the XMP profile to make sure that the installed DIMM count
per channel is supported and the requested voltage is supported.
To reduce complexity only XMP Profile 1 is read.
Allows my DRAM to run at 800Mhz instead of 666Mhz as encoded in the
default SPD.
Test system:
* Gigabyte GA-B75M-D3H
* Intel Pentium CPU G2130
Change-Id: Ib4dd68debfdcfdce138e813ad5b0e8e2ce3a40b2
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/13486
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins)
diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index 59f3b3b..40089e2 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -284,7 +284,7 @@
static void dram_find_spds_ddr3(spd_raw_data * spd, dimm_info * dimm,
ramctr_timing * ctrl)
{
- int dimms = 0;
+ int dimms = 0, dimms_on_channel;
int channel, slot, spd_slot;
memset (ctrl->rankmap, 0, sizeof (ctrl->rankmap));
@@ -295,9 +295,37 @@
FOR_ALL_CHANNELS {
ctrl->channel_size_mb[channel] = 0;
+ dimms_on_channel = 0;
+ /* count dimms on channel */
for (slot = 0; slot < NUM_SLOTS; slot++) {
spd_slot = 2 * channel + slot;
spd_decode_ddr3(&dimm->dimm[channel][slot], spd[spd_slot]);
+ if (dimm->dimm[channel][slot].dram_type == SPD_MEMORY_TYPE_SDRAM_DDR3)
+ dimms_on_channel++;
+ }
+
+ for (slot = 0; slot < NUM_SLOTS; slot++) {
+ spd_slot = 2 * channel + slot;
+ /* search for XMP profile */
+ spd_xmp_decode_ddr3(&dimm->dimm[channel][slot],
+ spd[spd_slot],
+ DDR3_XMP_PROFILE_1);
+
+ if (dimm->dimm[channel][slot].dram_type != SPD_MEMORY_TYPE_SDRAM_DDR3) {
+ printram("No valid XMP profile found.\n");
+ spd_decode_ddr3(&dimm->dimm[channel][slot], spd[spd_slot]);
+ } else if (dimms_on_channel > dimm->dimm[channel][slot].dimms_per_channel) {
+ printram("XMP profile supports %u DIMMs, but %u DIMMs are installed.\n",
+ dimm->dimm[channel][slot].dimms_per_channel,
+ dimms_on_channel);
+ spd_decode_ddr3(&dimm->dimm[channel][slot], spd[spd_slot]);
+ } else if (dimm->dimm[channel][slot].voltage != 1500) {
+ /* TODO: support other DDR3 voltage than 1500mV */
+ printram("XMP profile's requested %u mV is unsupported.\n",
+ dimm->dimm[channel][slot].voltage);
+ spd_decode_ddr3(&dimm->dimm[channel][slot], spd[spd_slot]);
+ }
+
if (dimm->dimm[channel][slot].dram_type != SPD_MEMORY_TYPE_SDRAM_DDR3) {
// set dimm invalid
dimm->dimm[channel][slot].ranks = 0;