[coreboot-gerrit] Change in coreboot[master]: soc/mediatek/mt8183: Verify checksum of cached calibration data

[Yu-Ping Wu (Code Review)]

Yu-Ping Wu has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/36014 )

Change subject: soc/mediatek/mt8183: Verify checksum of cached calibration data
......................................................................

soc/mediatek/mt8183: Verify checksum of cached calibration data

The checksum is stored in the header of calibration data and saved to
SPI flash. After reading the data from flash, checksum is used to verify
the integrity of the calibration parameters.

BUG=b:139099592
BRANCH=kukui
TEST=Calibration data successfully loaded from flash

Change-Id: Ie4a0688ed6e560d4c0c6b316f44e52fd10d71a9d
Signed-off-by: Yu-Ping Wu 
---
M src/soc/mediatek/mt8183/dramc_param.c
M src/soc/mediatek/mt8183/memory.c
2 files changed, 14 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/14/36014/1

diff --git a/src/soc/mediatek/mt8183/dramc_param.c b/src/soc/mediatek/mt8183/dramc_param.c
index ef3c191..bf1fee4 100644
--- a/src/soc/mediatek/mt8183/dramc_param.c
+++ b/src/soc/mediatek/mt8183/dramc_param.c
@@ -35,7 +35,6 @@
    if (hdr->size != sizeof(*param))
    	return DRAMC_ERR_INVALID_SIZE;

-	/* TODO(hungte) Verify and check hdr->checksum. */
    return DRAMC_SUCCESS;
 }

diff --git a/src/soc/mediatek/mt8183/memory.c b/src/soc/mediatek/mt8183/memory.c
index e97ea21..b536ebc 100644
--- a/src/soc/mediatek/mt8183/memory.c
+++ b/src/soc/mediatek/mt8183/memory.c
@@ -16,6 +16,7 @@
 #include <assert.h>
 #include <cbfs.h>
 #include <console/console.h>
+#include <ip_checksum.h>
 #include <soc/dramc_param.h>
 #include <soc/dramc_pi_api.h>
 #include <soc/emi.h>
@@ -70,6 +71,12 @@
    printk(BIOS_DEBUG, "header.checksum = %#x\n", header->checksum);
 }

+static u32 compute_checksum(const struct dramc_param *dparam)
+{
+	return (u32)compute_ip_checksum(dparam->freq_params,
+					sizeof(dparam->freq_params));
+}
+
 static int dram_run_fast_calibration(const struct dramc_param *dparam,
    			     u16 config)
 {
@@ -88,6 +95,12 @@
    	return -1;
    }

+	if (compute_checksum(dparam) != dparam->header.checksum) {
+		printk(BIOS_ERR,
+		       "Invalid DRAM calibration checksum from flash\n");
+		return -1;
+	}
+
    return 0;
 }

@@ -165,6 +178,7 @@
    	printk(BIOS_INFO, "Successfully loaded DRAM blobs and "
    	       "ran DRAM calibration\n");
    	set_source_to_flash(dparam->freq_params);
+		dparam->header.checksum = compute_checksum(dparam);
    	dparam_ops->write_to_flash(dparam);
    	printk(BIOS_DEBUG, "Calibration params saved to flash: "
    	       "version=%#x, size=%#x\n",