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-rw-r--r--config/coreboot/default/patches/0040-nb-intel-gm45-Make-DDR2-raminit-work.patch223
-rw-r--r--config/coreboot/default/patches/0041-nb-intel-gm45-Make-DDR2-raminit-work.patch269
-rw-r--r--config/coreboot/default/patches/0042-mb-dell-e6400-Use-100-MHz-reference-clock-for-displa.patch52
3 files changed, 544 insertions, 0 deletions
diff --git a/config/coreboot/default/patches/0040-nb-intel-gm45-Make-DDR2-raminit-work.patch b/config/coreboot/default/patches/0040-nb-intel-gm45-Make-DDR2-raminit-work.patch
new file mode 100644
index 00000000..b673b5f6
--- /dev/null
+++ b/config/coreboot/default/patches/0040-nb-intel-gm45-Make-DDR2-raminit-work.patch
@@ -0,0 +1,223 @@
+From fe5e1655be8cdb8eff1659e5ce6acbd06b9a7620 Mon Sep 17 00:00:00 2001
+From: Angel Pons <th3fanbus@gmail.com>
+Date: Mon, 10 May 2021 22:40:59 +0200
+Subject: [PATCH 1/3] nb/intel/gm45: Make DDR2 raminit work
+
+List of changes:
+ - Update some timing and ODT values
+ - Patch RCOMP calibration to better match what MRC binaries do
+ - Replay a hardcoded list of RCOMP codes after RcvEn
+
+This makes raminit work at DDR2-800 speeds and fixes S3 resume as well.
+Tested on Toshiba Satellite A300-1ME with two 2 GiB DDR2-800 SO-DIMMs.
+
+Change-Id: Ibaee524b8ff652ddadd66cb0eb680401b988ff7c
+Signed-off-by: Angel Pons <th3fanbus@gmail.com>
+---
+ src/northbridge/intel/gm45/gm45.h | 2 +-
+ src/northbridge/intel/gm45/raminit.c | 90 +++++++++++++++++--
+ .../intel/gm45/raminit_rcomp_calibration.c | 27 ++++--
+ 3 files changed, 106 insertions(+), 13 deletions(-)
+
+diff --git a/src/northbridge/intel/gm45/gm45.h b/src/northbridge/intel/gm45/gm45.h
+index 5d9ac56606..338260ea7a 100644
+--- a/src/northbridge/intel/gm45/gm45.h
++++ b/src/northbridge/intel/gm45/gm45.h
+@@ -420,7 +420,7 @@ void igd_compute_ggc(sysinfo_t *const sysinfo);
+ int raminit_read_vco_index(void);
+ u32 raminit_get_rank_addr(unsigned int channel, unsigned int rank);
+
+-void raminit_rcomp_calibration(stepping_t stepping);
++void raminit_rcomp_calibration(int ddr_type, stepping_t stepping);
+ void raminit_reset_readwrite_pointers(void);
+ void raminit_receive_enable_calibration(int ddr_type, const timings_t *, const dimminfo_t *);
+ void raminit_write_training(const mem_clock_t, const dimminfo_t *, int s3resume);
+diff --git a/src/northbridge/intel/gm45/raminit.c b/src/northbridge/intel/gm45/raminit.c
+index b7e013959a..df8f46fbbc 100644
+--- a/src/northbridge/intel/gm45/raminit.c
++++ b/src/northbridge/intel/gm45/raminit.c
+@@ -1047,7 +1047,7 @@ static void rcomp_initialization(const int spd_type, const stepping_t stepping,
+ }
+
+ /* Perform RCOMP calibration for DDR3. */
+- raminit_rcomp_calibration(stepping);
++ raminit_rcomp_calibration(spd_type, stepping);
+
+ /* Run initial RCOMP. */
+ mchbar_setbits32(0x418, 1 << 17);
+@@ -1117,7 +1117,7 @@ static void dram_program_timings(const int spd_type, const timings_t *const timi
+ reg = (reg & ~(0xf << 10)) | (2 << 10);
+ else
+ reg = (reg & ~(0xf << 10)) | (3 << 10);
+- reg = (reg & ~(0x7 << 5)) | (3 << 5);
++ reg = (reg & ~(0x7 << 5)) | (2 << 5);
+ } else if (timings->mem_clock != MEM_CLOCK_1067MT) {
+ reg = (reg & ~(0x7 << 15)) | ((9 - timings->CAS) << 15);
+ reg = (reg & ~(0xf << 10)) | ((timings->CAS - 3) << 10);
+@@ -1286,11 +1286,11 @@ static void ddr2_odt_setup(const timings_t *const timings, const int sff)
+ reg = (reg & ~(0xf << (44 - 32))) | (8 << (44 - 32));
+ reg = (reg & ~(0xf << (40 - 32))) | (7 << (40 - 32));
+ if (timings->mem_clock == MEM_CLOCK_667MT) {
+- reg = (reg & ~(0xf << (36 - 32))) | (4 << (36 - 32));
+- reg = (reg & ~(0xf << (32 - 32))) | (4 << (32 - 32));
++ reg = (reg & ~(0xf << (36 - 32))) | (8 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (8 << (32 - 32));
+ } else {
+- reg = (reg & ~(0xf << (36 - 32))) | (5 << (36 - 32));
+- reg = (reg & ~(0xf << (32 - 32))) | (5 << (32 - 32));
++ reg = (reg & ~(0xf << (36 - 32))) | (9 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (9 << (32 - 32));
+ }
+ mchbar_write32(CxODT_HIGH(ch), reg);
+
+@@ -2209,6 +2209,84 @@ void raminit(sysinfo_t *const sysinfo, const int s3resume)
+ raminit_write_training(timings->mem_clock, dimms, s3resume);
+ }
+
++ /*
++ * Program hardcoded DDR2-800 RCOMP SRAM codes. This must be done
++ * after receiver enable calibration, otherwise raminit sometimes
++ * completes with non-working memory.
++ */
++ mchbar_write32(0x0530, 0x06060005);
++ mchbar_write32(0x0680, 0x06060606);
++ mchbar_write32(0x0684, 0x08070606);
++ mchbar_write32(0x0688, 0x0e0e0c0a);
++ mchbar_write32(0x068c, 0x0e0e0e0e);
++ mchbar_write32(0x0698, 0x06060606);
++ mchbar_write32(0x069c, 0x08070606);
++ mchbar_write32(0x06a0, 0x0c0c0b0a);
++ mchbar_write32(0x06a4, 0x0c0c0c0c);
++
++ mchbar_write32(0x06c0, 0x02020202);
++ mchbar_write32(0x06c4, 0x03020202);
++ mchbar_write32(0x06c8, 0x04040403);
++ mchbar_write32(0x06cc, 0x04040404);
++ mchbar_write32(0x06d8, 0x02020202);
++ mchbar_write32(0x06dc, 0x03020202);
++ mchbar_write32(0x06e0, 0x04040403);
++ mchbar_write32(0x06e4, 0x04040404);
++
++ mchbar_write32(0x0700, 0x02020202);
++ mchbar_write32(0x0704, 0x03020202);
++ mchbar_write32(0x0708, 0x04040403);
++ mchbar_write32(0x070c, 0x04040404);
++ mchbar_write32(0x0718, 0x02020202);
++ mchbar_write32(0x071c, 0x03020202);
++ mchbar_write32(0x0720, 0x04040403);
++ mchbar_write32(0x0724, 0x04040404);
++
++ mchbar_write32(0x0740, 0x02020202);
++ mchbar_write32(0x0744, 0x03020202);
++ mchbar_write32(0x0748, 0x04040403);
++ mchbar_write32(0x074c, 0x04040404);
++ mchbar_write32(0x0758, 0x02020202);
++ mchbar_write32(0x075c, 0x03020202);
++ mchbar_write32(0x0760, 0x04040403);
++ mchbar_write32(0x0764, 0x04040404);
++
++ mchbar_write32(0x0780, 0x06060606);
++ mchbar_write32(0x0784, 0x09070606);
++ mchbar_write32(0x0788, 0x0e0e0c0b);
++ mchbar_write32(0x078c, 0x0e0e0e0e);
++ mchbar_write32(0x0798, 0x06060606);
++ mchbar_write32(0x079c, 0x09070606);
++ mchbar_write32(0x07a0, 0x0d0d0c0b);
++ mchbar_write32(0x07a4, 0x0d0d0d0d);
++
++ mchbar_write32(0x07c0, 0x06060606);
++ mchbar_write32(0x07c4, 0x09070606);
++ mchbar_write32(0x07c8, 0x0e0e0c0b);
++ mchbar_write32(0x07cc, 0x0e0e0e0e);
++ mchbar_write32(0x07d8, 0x06060606);
++ mchbar_write32(0x07dc, 0x09070606);
++ mchbar_write32(0x07e0, 0x0d0d0c0b);
++ mchbar_write32(0x07e4, 0x0d0d0d0d);
++
++ mchbar_write32(0x0840, 0x06060606);
++ mchbar_write32(0x0844, 0x08070606);
++ mchbar_write32(0x0848, 0x0e0e0c0a);
++ mchbar_write32(0x084c, 0x0e0e0e0e);
++ mchbar_write32(0x0858, 0x06060606);
++ mchbar_write32(0x085c, 0x08070606);
++ mchbar_write32(0x0860, 0x0c0c0b0a);
++ mchbar_write32(0x0864, 0x0c0c0c0c);
++
++ mchbar_write32(0x0880, 0x02020202);
++ mchbar_write32(0x0884, 0x03020202);
++ mchbar_write32(0x0888, 0x04040403);
++ mchbar_write32(0x088c, 0x04040404);
++ mchbar_write32(0x0898, 0x02020202);
++ mchbar_write32(0x089c, 0x03020202);
++ mchbar_write32(0x08a0, 0x04040403);
++ mchbar_write32(0x08a4, 0x04040404);
++
+ igd_compute_ggc(sysinfo);
+
+ /* Program final memory map (with real values). */
+diff --git a/src/northbridge/intel/gm45/raminit_rcomp_calibration.c b/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
+index aef863f05a..b74765fd9c 100644
+--- a/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
++++ b/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
+@@ -161,11 +161,13 @@ static void lookup_and_write(const int a1step,
+ mchbar += 4;
+ }
+ }
+-void raminit_rcomp_calibration(const stepping_t stepping) {
++void raminit_rcomp_calibration(int ddr_type, const stepping_t stepping) {
+ const int a1step = stepping >= STEPPING_CONVERSION_A1;
+
+ int i;
+
++ char magic_comp[2] = {0};
++
+ enum {
+ PULL_UP = 0,
+ PULL_DOWN = 1,
+@@ -196,6 +198,10 @@ void raminit_rcomp_calibration(const stepping_t stepping) {
+ reg = mchbar_read32(0x518);
+ lut_idx[channel][group][PULL_UP] = (reg >> 24) & 0x7f;
+ lut_idx[channel][group][PULL_DOWN] = (reg >> 16) & 0x7f;
++ if (i == 1) {
++ magic_comp[0] = (reg >> 8) & 0x3f;
++ magic_comp[1] = (reg >> 0) & 0x3f;
++ }
+ }
+ /* Cleanup? */
+ mchbar_setbits32(0x400, 1 << 3);
+@@ -216,13 +222,19 @@ void raminit_rcomp_calibration(const stepping_t stepping) {
+ for (channel = 0; channel < 2; ++channel) {
+ for (group = 0; group < 6; ++group) {
+ for (pu_pd = PULL_DOWN; pu_pd >= PULL_UP; --pu_pd) {
+- lookup_and_write(
+- a1step,
+- lut_idx[channel][group][pu_pd] - 7,
+- ddr3_lookup_schedule[group][pu_pd],
+- mchbar);
++ if (ddr_type == DDR3) {
++ lookup_and_write(
++ a1step,
++ lut_idx[channel][group][pu_pd] - 7,
++ ddr3_lookup_schedule[group][pu_pd],
++ mchbar);
++ }
+ mchbar += 0x0018;
+ }
++ if (ddr_type == DDR2) {
++ mchbar_clrsetbits32(mchbar + 0, 0x7f << 24, lut_idx[channel][group][PULL_DOWN] << 24);
++ mchbar_clrsetbits32(mchbar + 4, 0x7f << 0, lut_idx[channel][group][PULL_UP] << 0);
++ }
+ mchbar += 0x0010;
+ /* Channel B knows only the first two groups. */
+ if ((1 == channel) && (1 == group))
+@@ -230,4 +242,7 @@ void raminit_rcomp_calibration(const stepping_t stepping) {
+ }
+ mchbar += 0x0040;
+ }
++
++ mchbar_clrsetbits32(0x4d0, 0x3f << 26, magic_comp[0] << 26);
++ mchbar_clrsetbits32(0x4d0, 0x3f << 20, magic_comp[1] << 20);
+ }
+--
+2.39.2
+
diff --git a/config/coreboot/default/patches/0041-nb-intel-gm45-Make-DDR2-raminit-work.patch b/config/coreboot/default/patches/0041-nb-intel-gm45-Make-DDR2-raminit-work.patch
new file mode 100644
index 00000000..2f50be66
--- /dev/null
+++ b/config/coreboot/default/patches/0041-nb-intel-gm45-Make-DDR2-raminit-work.patch
@@ -0,0 +1,269 @@
+From 65510f6ea53d6f23f47df69d623810aa87041918 Mon Sep 17 00:00:00 2001
+From: Leah Rowe <info@minifree.org>
+Date: Tue, 6 Aug 2024 00:50:24 +0100
+Subject: [PATCH 2/3] nb/gm45: Fix Angel's DDR2 RCOMP fix on DDR3 boards
+
+We add this patch:
+
+commit commit_id_here
+Author: Angel Pons <th3fanbus@gmail.com>
+Date: Mon May 10 22:40:59 2021 +0200
+
+ nb/intel/gm45: Make DDR2 raminit work
+
+This patch was original applied, in lbmk, only on coreboot/dell,
+separately from coreboot/default, which was wasteful because it
+meant having an entire coreboot tree just for a single board. We
+did this, because the DDR2 RCOMP fix happened to break DDR3 init
+on other boards.
+
+What *this* new patch does on top of Angel's patch, is make sure
+that their changes only apply to DDR2, while DDR3 behaviour remains
+unchanged. This means that the Dell Latitude E6400 can be supported
+in the main coreboot tree, within lbmk.
+
+Essentially, this patch restores the old behaviour, prior to applying
+Angel's patch, only when DDR3 memory is used.
+
+Signed-off-by: Leah Rowe <info@minifree.org>
+---
+ src/northbridge/intel/gm45/raminit.c | 182 ++++++++++--------
+ .../intel/gm45/raminit_rcomp_calibration.c | 9 +-
+ 2 files changed, 104 insertions(+), 87 deletions(-)
+
+diff --git a/src/northbridge/intel/gm45/raminit.c b/src/northbridge/intel/gm45/raminit.c
+index df8f46fbbc..b051374eaa 100644
+--- a/src/northbridge/intel/gm45/raminit.c
++++ b/src/northbridge/intel/gm45/raminit.c
+@@ -1117,7 +1117,10 @@ static void dram_program_timings(const int spd_type, const timings_t *const timi
+ reg = (reg & ~(0xf << 10)) | (2 << 10);
+ else
+ reg = (reg & ~(0xf << 10)) | (3 << 10);
+- reg = (reg & ~(0x7 << 5)) | (2 << 5);
++ if (sysinfo->spd_type == DDR2)
++ reg = (reg & ~(0x7 << 5)) | (2 << 5);
++ else
++ reg = (reg & ~(0x7 << 5)) | (3 << 5);
+ } else if (timings->mem_clock != MEM_CLOCK_1067MT) {
+ reg = (reg & ~(0x7 << 15)) | ((9 - timings->CAS) << 15);
+ reg = (reg & ~(0xf << 10)) | ((timings->CAS - 3) << 10);
+@@ -1285,12 +1288,23 @@ static void ddr2_odt_setup(const timings_t *const timings, const int sff)
+ reg = (reg & ~(0x7 << (48 - 32))) | ((timings->CAS - 2) << (48 - 32));
+ reg = (reg & ~(0xf << (44 - 32))) | (8 << (44 - 32));
+ reg = (reg & ~(0xf << (40 - 32))) | (7 << (40 - 32));
+- if (timings->mem_clock == MEM_CLOCK_667MT) {
+- reg = (reg & ~(0xf << (36 - 32))) | (8 << (36 - 32));
+- reg = (reg & ~(0xf << (32 - 32))) | (8 << (32 - 32));
++ if (sysinfo->spd_type == DDR2) {
++ if (timings->mem_clock == MEM_CLOCK_667MT) {
++ reg = (reg & ~(0xf << (36 - 32))) | (8 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (8 << (32 - 32));
++ } else {
++ reg = (reg & ~(0xf << (36 - 32))) | (9 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (9 << (32 - 32));
++ }
+ } else {
+- reg = (reg & ~(0xf << (36 - 32))) | (9 << (36 - 32));
+- reg = (reg & ~(0xf << (32 - 32))) | (9 << (32 - 32));
++ /* DDR3 */
++ if (timings->mem_clock == MEM_CLOCK_667MT) {
++ reg = (reg & ~(0xf << (36 - 32))) | (4 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (4 << (32 - 32));
++ } else {
++ reg = (reg & ~(0xf << (36 - 32))) | (5 << (36 - 32));
++ reg = (reg & ~(0xf << (32 - 32))) | (5 << (32 - 32));
++ }
+ }
+ mchbar_write32(CxODT_HIGH(ch), reg);
+
+@@ -2209,83 +2223,85 @@ void raminit(sysinfo_t *const sysinfo, const int s3resume)
+ raminit_write_training(timings->mem_clock, dimms, s3resume);
+ }
+
+- /*
+- * Program hardcoded DDR2-800 RCOMP SRAM codes. This must be done
+- * after receiver enable calibration, otherwise raminit sometimes
+- * completes with non-working memory.
+- */
+- mchbar_write32(0x0530, 0x06060005);
+- mchbar_write32(0x0680, 0x06060606);
+- mchbar_write32(0x0684, 0x08070606);
+- mchbar_write32(0x0688, 0x0e0e0c0a);
+- mchbar_write32(0x068c, 0x0e0e0e0e);
+- mchbar_write32(0x0698, 0x06060606);
+- mchbar_write32(0x069c, 0x08070606);
+- mchbar_write32(0x06a0, 0x0c0c0b0a);
+- mchbar_write32(0x06a4, 0x0c0c0c0c);
+-
+- mchbar_write32(0x06c0, 0x02020202);
+- mchbar_write32(0x06c4, 0x03020202);
+- mchbar_write32(0x06c8, 0x04040403);
+- mchbar_write32(0x06cc, 0x04040404);
+- mchbar_write32(0x06d8, 0x02020202);
+- mchbar_write32(0x06dc, 0x03020202);
+- mchbar_write32(0x06e0, 0x04040403);
+- mchbar_write32(0x06e4, 0x04040404);
+-
+- mchbar_write32(0x0700, 0x02020202);
+- mchbar_write32(0x0704, 0x03020202);
+- mchbar_write32(0x0708, 0x04040403);
+- mchbar_write32(0x070c, 0x04040404);
+- mchbar_write32(0x0718, 0x02020202);
+- mchbar_write32(0x071c, 0x03020202);
+- mchbar_write32(0x0720, 0x04040403);
+- mchbar_write32(0x0724, 0x04040404);
+-
+- mchbar_write32(0x0740, 0x02020202);
+- mchbar_write32(0x0744, 0x03020202);
+- mchbar_write32(0x0748, 0x04040403);
+- mchbar_write32(0x074c, 0x04040404);
+- mchbar_write32(0x0758, 0x02020202);
+- mchbar_write32(0x075c, 0x03020202);
+- mchbar_write32(0x0760, 0x04040403);
+- mchbar_write32(0x0764, 0x04040404);
+-
+- mchbar_write32(0x0780, 0x06060606);
+- mchbar_write32(0x0784, 0x09070606);
+- mchbar_write32(0x0788, 0x0e0e0c0b);
+- mchbar_write32(0x078c, 0x0e0e0e0e);
+- mchbar_write32(0x0798, 0x06060606);
+- mchbar_write32(0x079c, 0x09070606);
+- mchbar_write32(0x07a0, 0x0d0d0c0b);
+- mchbar_write32(0x07a4, 0x0d0d0d0d);
+-
+- mchbar_write32(0x07c0, 0x06060606);
+- mchbar_write32(0x07c4, 0x09070606);
+- mchbar_write32(0x07c8, 0x0e0e0c0b);
+- mchbar_write32(0x07cc, 0x0e0e0e0e);
+- mchbar_write32(0x07d8, 0x06060606);
+- mchbar_write32(0x07dc, 0x09070606);
+- mchbar_write32(0x07e0, 0x0d0d0c0b);
+- mchbar_write32(0x07e4, 0x0d0d0d0d);
+-
+- mchbar_write32(0x0840, 0x06060606);
+- mchbar_write32(0x0844, 0x08070606);
+- mchbar_write32(0x0848, 0x0e0e0c0a);
+- mchbar_write32(0x084c, 0x0e0e0e0e);
+- mchbar_write32(0x0858, 0x06060606);
+- mchbar_write32(0x085c, 0x08070606);
+- mchbar_write32(0x0860, 0x0c0c0b0a);
+- mchbar_write32(0x0864, 0x0c0c0c0c);
+-
+- mchbar_write32(0x0880, 0x02020202);
+- mchbar_write32(0x0884, 0x03020202);
+- mchbar_write32(0x0888, 0x04040403);
+- mchbar_write32(0x088c, 0x04040404);
+- mchbar_write32(0x0898, 0x02020202);
+- mchbar_write32(0x089c, 0x03020202);
+- mchbar_write32(0x08a0, 0x04040403);
+- mchbar_write32(0x08a4, 0x04040404);
++ if (sysinfo->spd_type == DDR2) {
++ /*
++ * Program hardcoded DDR2-800 RCOMP SRAM codes. This must be done
++ * after receiver enable calibration, otherwise raminit sometimes
++ * completes with non-working memory.
++ */
++ mchbar_write32(0x0530, 0x06060005);
++ mchbar_write32(0x0680, 0x06060606);
++ mchbar_write32(0x0684, 0x08070606);
++ mchbar_write32(0x0688, 0x0e0e0c0a);
++ mchbar_write32(0x068c, 0x0e0e0e0e);
++ mchbar_write32(0x0698, 0x06060606);
++ mchbar_write32(0x069c, 0x08070606);
++ mchbar_write32(0x06a0, 0x0c0c0b0a);
++ mchbar_write32(0x06a4, 0x0c0c0c0c);
++
++ mchbar_write32(0x06c0, 0x02020202);
++ mchbar_write32(0x06c4, 0x03020202);
++ mchbar_write32(0x06c8, 0x04040403);
++ mchbar_write32(0x06cc, 0x04040404);
++ mchbar_write32(0x06d8, 0x02020202);
++ mchbar_write32(0x06dc, 0x03020202);
++ mchbar_write32(0x06e0, 0x04040403);
++ mchbar_write32(0x06e4, 0x04040404);
++
++ mchbar_write32(0x0700, 0x02020202);
++ mchbar_write32(0x0704, 0x03020202);
++ mchbar_write32(0x0708, 0x04040403);
++ mchbar_write32(0x070c, 0x04040404);
++ mchbar_write32(0x0718, 0x02020202);
++ mchbar_write32(0x071c, 0x03020202);
++ mchbar_write32(0x0720, 0x04040403);
++ mchbar_write32(0x0724, 0x04040404);
++
++ mchbar_write32(0x0740, 0x02020202);
++ mchbar_write32(0x0744, 0x03020202);
++ mchbar_write32(0x0748, 0x04040403);
++ mchbar_write32(0x074c, 0x04040404);
++ mchbar_write32(0x0758, 0x02020202);
++ mchbar_write32(0x075c, 0x03020202);
++ mchbar_write32(0x0760, 0x04040403);
++ mchbar_write32(0x0764, 0x04040404);
++
++ mchbar_write32(0x0780, 0x06060606);
++ mchbar_write32(0x0784, 0x09070606);
++ mchbar_write32(0x0788, 0x0e0e0c0b);
++ mchbar_write32(0x078c, 0x0e0e0e0e);
++ mchbar_write32(0x0798, 0x06060606);
++ mchbar_write32(0x079c, 0x09070606);
++ mchbar_write32(0x07a0, 0x0d0d0c0b);
++ mchbar_write32(0x07a4, 0x0d0d0d0d);
++
++ mchbar_write32(0x07c0, 0x06060606);
++ mchbar_write32(0x07c4, 0x09070606);
++ mchbar_write32(0x07c8, 0x0e0e0c0b);
++ mchbar_write32(0x07cc, 0x0e0e0e0e);
++ mchbar_write32(0x07d8, 0x06060606);
++ mchbar_write32(0x07dc, 0x09070606);
++ mchbar_write32(0x07e0, 0x0d0d0c0b);
++ mchbar_write32(0x07e4, 0x0d0d0d0d);
++
++ mchbar_write32(0x0840, 0x06060606);
++ mchbar_write32(0x0844, 0x08070606);
++ mchbar_write32(0x0848, 0x0e0e0c0a);
++ mchbar_write32(0x084c, 0x0e0e0e0e);
++ mchbar_write32(0x0858, 0x06060606);
++ mchbar_write32(0x085c, 0x08070606);
++ mchbar_write32(0x0860, 0x0c0c0b0a);
++ mchbar_write32(0x0864, 0x0c0c0c0c);
++
++ mchbar_write32(0x0880, 0x02020202);
++ mchbar_write32(0x0884, 0x03020202);
++ mchbar_write32(0x0888, 0x04040403);
++ mchbar_write32(0x088c, 0x04040404);
++ mchbar_write32(0x0898, 0x02020202);
++ mchbar_write32(0x089c, 0x03020202);
++ mchbar_write32(0x08a0, 0x04040403);
++ mchbar_write32(0x08a4, 0x04040404);
++ }
+
+ igd_compute_ggc(sysinfo);
+
+diff --git a/src/northbridge/intel/gm45/raminit_rcomp_calibration.c b/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
+index b74765fd9c..5d4505e063 100644
+--- a/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
++++ b/src/northbridge/intel/gm45/raminit_rcomp_calibration.c
+@@ -198,7 +198,7 @@ void raminit_rcomp_calibration(int ddr_type, const stepping_t stepping) {
+ reg = mchbar_read32(0x518);
+ lut_idx[channel][group][PULL_UP] = (reg >> 24) & 0x7f;
+ lut_idx[channel][group][PULL_DOWN] = (reg >> 16) & 0x7f;
+- if (i == 1) {
++ if ((i == 1) && (ddr_type == DDR2)) {
+ magic_comp[0] = (reg >> 8) & 0x3f;
+ magic_comp[1] = (reg >> 0) & 0x3f;
+ }
+@@ -242,7 +242,8 @@ void raminit_rcomp_calibration(int ddr_type, const stepping_t stepping) {
+ }
+ mchbar += 0x0040;
+ }
+-
+- mchbar_clrsetbits32(0x4d0, 0x3f << 26, magic_comp[0] << 26);
+- mchbar_clrsetbits32(0x4d0, 0x3f << 20, magic_comp[1] << 20);
++ if (ddr_type == DDR2) {
++ mchbar_clrsetbits32(0x4d0, 0x3f << 26, magic_comp[0] << 26);
++ mchbar_clrsetbits32(0x4d0, 0x3f << 20, magic_comp[1] << 20);
++ }
+ }
+--
+2.39.2
+
diff --git a/config/coreboot/default/patches/0042-mb-dell-e6400-Use-100-MHz-reference-clock-for-displa.patch b/config/coreboot/default/patches/0042-mb-dell-e6400-Use-100-MHz-reference-clock-for-displa.patch
new file mode 100644
index 00000000..991dcf44
--- /dev/null
+++ b/config/coreboot/default/patches/0042-mb-dell-e6400-Use-100-MHz-reference-clock-for-displa.patch
@@ -0,0 +1,52 @@
+From b42ca30081b25cbabfb2659adca9d935ef3a8399 Mon Sep 17 00:00:00 2001
+From: Nicholas Chin <nic.c3.14@gmail.com>
+Date: Mon, 20 May 2024 10:24:16 -0600
+Subject: [PATCH 3/3] mb/dell/e6400: Use 100 MHz reference clock for display
+
+The E6400 uses a 100 MHz reference clock for spread spectrum support on
+LVDS, whereas libgfxinit previously assumed a 96 MHz input clock. For
+the more common 1280 x 800 display panels, the numerical error was not
+large enough to cause noticable issues, but the actual pixel clock
+frequency derived from a 100 MHz reference using PLL configs calculated
+assuming a 96 MHz reference was not close enough for 1440 x 900 panels,
+which require a much higher pixel clock. This resulted in a garbled
+display in the pre-OS graphics environment provided by libgfxinit.
+
+Signed-off-by: Nicholas Chin <nic.c3.14@gmail.com>
+---
+ src/mainboard/dell/e6400/Kconfig | 3 +++
+ src/northbridge/intel/gm45/Kconfig | 4 ++++
+ 2 files changed, 7 insertions(+)
+
+diff --git a/src/mainboard/dell/e6400/Kconfig b/src/mainboard/dell/e6400/Kconfig
+index 417d95fd5d..6fe1b1c456 100644
+--- a/src/mainboard/dell/e6400/Kconfig
++++ b/src/mainboard/dell/e6400/Kconfig
+@@ -19,6 +19,9 @@ config BOARD_SPECIFIC_OPTIONS
+ select INTEL_GMA_HAVE_VBT
+ select EC_DELL_MEC5035
+
++config INTEL_GMA_DPLL_REF_FREQ
++ default 100000000
++
+ config MAINBOARD_DIR
+ default "dell/e6400"
+
+diff --git a/src/northbridge/intel/gm45/Kconfig b/src/northbridge/intel/gm45/Kconfig
+index 8059e7ee80..5df5a93296 100644
+--- a/src/northbridge/intel/gm45/Kconfig
++++ b/src/northbridge/intel/gm45/Kconfig
+@@ -14,6 +14,10 @@ config NORTHBRIDGE_INTEL_GM45
+
+ if NORTHBRIDGE_INTEL_GM45
+
++config INTEL_GMA_DPLL_REF_FREQ
++ int
++ default 96000000
++
+ config VBOOT
+ select VBOOT_STARTS_IN_BOOTBLOCK
+
+--
+2.39.2
+