2 files changed, 97 insertions, 1 deletions
diff --git a/src/mainboard/google/rex/variants/screebo/Makefile.inc b/src/mainboard/google/rex/variants/screebo/Makefile.inc
index 6c29346470..228886c1bb 100644
--- a/src/mainboard/google/rex/variants/screebo/Makefile.inc
+++ b/src/mainboard/google/rex/variants/screebo/Makefile.inc
@@ -1,5 +1,5 @@
 bootblock-y += gpio.c
 
 romstage-y += gpio.c
-
+romstage-y += memory.c
 ramstage-y += gpio.c
diff --git a/src/mainboard/google/rex/variants/screebo/memory.c b/src/mainboard/google/rex/variants/screebo/memory.c
new file mode 100644
index 0000000000..ed26b67901
--- /dev/null
+++ b/src/mainboard/google/rex/variants/screebo/memory.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+#include <gpio.h>
+
+static const struct mb_cfg baseboard_memcfg = {
+	.type = MEM_TYPE_LP5X,
+
+	.rcomp = {
+		/* Baseboard uses only 100ohm Rcomp resistors */
+		.resistor = 100,
+	},
+
+	/* DQ byte map */
+	.lpx_dq_map = {
+		.ddr0 = {
+			.dq0 = {  9, 13, 12,  14, 8, 10, 11, 15 },
+			.dq1 = {  6,  5,  7,   4, 3,  2,  0,  1 },
+		},
+		.ddr1 = {
+			.dq0 = {  2,  0,  1,  3,  4,  5,  6,  7 },
+			.dq1 = { 14,  8, 12, 15, 11, 10,  9, 13 },
+		},
+		.ddr2 = {
+			.dq0 = {  9, 11, 10,  8, 15, 13, 14, 12 },
+			.dq1 = {  0,  6,  2,  3,  1,  4,  5,  7 },
+		},
+		.ddr3 = {
+			.dq0 = {  7,  2,  0,  3,  4,  1,  5,  6 },
+			.dq1 = {  8, 14, 12, 13, 11, 15,  9, 10 },
+		},
+		.ddr4 = {
+			.dq0 = { 14,  9, 12, 15, 11, 10,  8, 13 },
+			.dq1 = {  5,  7,  4,  6,  2,  1,  0,  3 },
+		},
+		.ddr5 = {
+			.dq0 = {  1,  5,  3,  6,  2,  7,  0,  4 },
+			.dq1 = { 10,  8, 11,  9, 12, 15, 14, 13 },
+		},
+		.ddr6 = {
+			.dq0 = { 10,  8,  9, 11, 13, 14, 15, 12 },
+			.dq1 = {  3,  7,  2,  0,  1,  4,  6,  5 },
+		},
+		.ddr7 = {
+			.dq0 = {  1,  2,  3,  0,  5,  7,  4,  6 },
+			.dq1 = { 14,  8, 12, 13, 15, 11, 10,  9 },
+		},
+	},
+
+	/* DQS CPU<>DRAM map */
+	.lpx_dqs_map = {
+		.ddr0 = { .dqs0 = 1, .dqs1 = 0 },
+		.ddr1 = { .dqs0 = 0, .dqs1 = 1 },
+		.ddr2 = { .dqs0 = 1, .dqs1 = 0 },
+		.ddr3 = { .dqs0 = 0, .dqs1 = 1 },
+		.ddr4 = { .dqs0 = 1, .dqs1 = 0 },
+		.ddr5 = { .dqs0 = 0, .dqs1 = 1 },
+		.ddr6 = { .dqs0 = 1, .dqs1 = 0 },
+		.ddr7 = { .dqs0 = 0, .dqs1 = 1 },
+	},
+
+	.lp5x_config = {
+		.ccc_config = 0x55,
+	},
+
+	.ect = 1, /* Early Command Training */
+};
+
+const struct mb_cfg *variant_memory_params(void)
+{
+	return &baseboard_memcfg;
+}
+
+int variant_memory_sku(void)
+{
+	gpio_t spd_gpios[] = {
+		GPIO_MEM_CONFIG_0,
+		GPIO_MEM_CONFIG_1,
+		GPIO_MEM_CONFIG_2,
+		GPIO_MEM_CONFIG_3,
+	};
+
+	return gpio_base2_value(spd_gpios, ARRAY_SIZE(spd_gpios));
+}
+
+bool variant_is_half_populated(void)
+{
+	return gpio_get(GPIO_MEM_CH_SEL);
+}
+
+void variant_get_spd_info(struct mem_spd *spd_info)
+{
+	spd_info->topo = MEM_TOPO_MEMORY_DOWN;
+	spd_info->cbfs_index = variant_memory_sku();
+}