Change in coreboot[master]: mb/google/asurada: Init dram in romstage

[CK HU (Code Review)]

Hello Duan huayang,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/44568

to review the following change.

Change subject: mb/google/asurada: Init dram in romstage
......................................................................

mb/google/asurada: Init dram in romstage

Signed-off-by: Huayang Duan 
Change-Id: Ied350570a695cca1424a6562e41120bcaf467797
---
M src/mainboard/google/asurada/Makefile.inc
A src/mainboard/google/asurada/romstage.c
2 files changed, 50 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/44568/1

diff --git a/src/mainboard/google/asurada/Makefile.inc b/src/mainboard/google/asurada/Makefile.inc
index 8395e4a..c742539 100644
--- a/src/mainboard/google/asurada/Makefile.inc
+++ b/src/mainboard/google/asurada/Makefile.inc
@@ -8,6 +8,7 @@

romstage-y += memlayout.ld
 romstage-y += boardid.c
+romstage-y += romstage.c
 romstage-y += sdram_configs.c

ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/asurada/romstage.c b/src/mainboard/google/asurada/romstage.c
new file mode 100644
index 0000000..8fa2f38
--- /dev/null
+++ b/src/mainboard/google/asurada/romstage.c
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <arch/stages.h>
+#include <console/console.h>
+#include <fmap.h>
+#include <soc/dramc_param.h>
+#include <soc/emi.h>
+#include <soc/mmu_operations.h>
+
+/* This must be defined in chromeos.fmd in same name and size. */
+#define CALIBRATION_REGION		"RW_DDR_TRAINING"
+#define CALIBRATION_REGION_SIZE		0x2000
+
+_Static_assert(sizeof(struct dramc_param) <= CALIBRATION_REGION_SIZE,
+	       "sizeof(struct dramc_param) exceeds " CALIBRATION_REGION);
+
+static bool read_calibration_data_from_flash(struct dramc_param *dparam)
+{
+	const size_t length = sizeof(*dparam);
+	size_t ret = fmap_read_area(CALIBRATION_REGION, dparam, length);
+	printk(BIOS_DEBUG, "read data from flash, ret=%#lx, length=%#lx\n", ret, length);
+
+	return ret == length;
+}
+
+static bool write_calibration_data_to_flash(const struct dramc_param *dparam)
+{
+	const size_t length = sizeof(*dparam);
+	size_t ret = fmap_overwrite_area(CALIBRATION_REGION, dparam, length);
+	printk(BIOS_DEBUG, "write data from flash, ret=%#lx, length=%#lx\n", ret, length);
+
+	return ret == length;
+}
+
+/* dramc_param is ~2K and too large to fit in stack. */
+static struct dramc_param dramc_parameter = {0x0};
+
+static struct dramc_param_ops dparam_ops = {
+	.param = &dramc_parameter,
+	.read_from_flash = &read_calibration_data_from_flash,
+	.write_to_flash = &write_calibration_data_to_flash,
+};
+
+void platform_romstage_main(void)
+{
+	mt_mem_init(&dparam_ops);
+	mtk_mmu_after_dram();
+	printk(BIOS_WARNING, "after mt_mem_init\n");
+}