soc/intel/common/cse: Reorganize firmware update checks for CSE Lite
`cse_fw_update()` is currently checking whether an update is required
by comparing versions once and then again comparing versions later in
`cse_is_downgrade_instance()` to determine if the update is an upgrade
or downgrade. Additionally, if CSE RW partition is corrupt (determined
based on `cse_is_rw_bp_sign_valid()`), `cse_is_downgrade_instance()`
ends up using the corrupted version information to determine if it is
a downgrade instance.
This change reorganizes the firmware update checks to return different
status values:
1. CSE_UPDATE_NOT_REQUIRED: No update required. Versions match.
2. CSE_UPDATE_UPGRADE: Update required and it is an upgrade.
3. CSE_UPDATE_DOWNGRADE: Update required and it is a
downgrade (requires data clear).
4. CSE_UPDATE_CORRUPTED: `cse_is_rw_bp_sign_valid()` failed and hence
requires data clear.
5. CSE_UPDATE_METADATA_ERROR: Unable to read CSE metadata from CBFS.
This change also prepares the file for follow up changes which
completely drop cse_rw_metadata structure.
BUG=b:184892226
Change-Id: Iabecab8e373e65a11ba7fe1bfc125467571a0588
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58157
Reviewed-by: Sridhar Siricilla <sridhar.siricilla@intel.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/common/block/cse/cse_lite.c b/src/soc/intel/common/block/cse/cse_lite.c
index 762de2a..b381c48 100644
--- a/src/soc/intel/common/block/cse/cse_lite.c
+++ b/src/soc/intel/common/block/cse/cse_lite.c
@@ -502,27 +502,16 @@
* If ver_cmp_status < 0, coreboot downgrades CSE RW region
* If ver_cmp_status > 0, coreboot upgrades CSE RW region
*/
-static int cse_check_version_mismatch(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata)
+static int compare_cse_version(const struct fw_version *a, const struct fw_version *b)
{
- const struct fw_version *cse_rw_ver;
-
- printk(BIOS_DEBUG, "cse_lite: CSE CBFS RW version : %d.%d.%d.%d\n",
- source_metadata->version.major,
- source_metadata->version.minor,
- source_metadata->version.hotfix,
- source_metadata->version.build);
-
- cse_rw_ver = cse_get_rw_version(cse_bp_info);
-
- if (source_metadata->version.major != cse_rw_ver->major)
- return source_metadata->version.major - cse_rw_ver->major;
- else if (source_metadata->version.minor != cse_rw_ver->minor)
- return source_metadata->version.minor - cse_rw_ver->minor;
- else if (source_metadata->version.hotfix != cse_rw_ver->hotfix)
- return source_metadata->version.hotfix - cse_rw_ver->hotfix;
+ if (a->major != b->major)
+ return a->major - b->major;
+ else if (a->minor != b->minor)
+ return a->minor - b->minor;
+ else if (a->hotfix != b->hotfix)
+ return a->hotfix - b->hotfix;
else
- return source_metadata->version.build - cse_rw_ver->build;
+ return a->build - b->build;
}
/* The function calculates SHA-256 of CSE RW blob and compares it with the provided SHA value */
@@ -568,24 +557,43 @@
return true;
}
-static bool cse_is_rw_version_latest(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata)
-{
- return !cse_check_version_mismatch(cse_bp_info, source_metadata);
-}
+enum cse_update_status {
+ CSE_UPDATE_NOT_REQUIRED,
+ CSE_UPDATE_UPGRADE,
+ CSE_UPDATE_DOWNGRADE,
+ CSE_UPDATE_CORRUPTED,
+ CSE_UPDATE_METADATA_ERROR,
+};
-static bool cse_is_downgrade_instance(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata)
-{
- return cse_check_version_mismatch(cse_bp_info, source_metadata) < 0;
-}
+static struct cse_rw_metadata source_metadata;
-static bool cse_is_update_required(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata,
- struct region_device *target_rdev)
+static enum cse_update_status cse_check_update_status(const struct cse_bp_info *cse_bp_info,
+ struct region_device *target_rdev)
{
- return (!cse_is_rw_bp_sign_valid(target_rdev) ||
- !cse_is_rw_version_latest(cse_bp_info, source_metadata));
+ int ret;
+
+ if (!cse_is_rw_bp_sign_valid(target_rdev))
+ return CSE_UPDATE_CORRUPTED;
+
+ if (cbfs_load(CONFIG_SOC_INTEL_CSE_RW_METADATA_CBFS_NAME, &source_metadata,
+ sizeof(source_metadata)) != sizeof(source_metadata)) {
+ printk(BIOS_ERR, "cse_lite: Failed to get CSE CBFS RW metadata\n");
+ return CSE_UPDATE_METADATA_ERROR;
+ }
+
+ printk(BIOS_DEBUG, "cse_lite: CSE CBFS RW version : %d.%d.%d.%d\n",
+ source_metadata.version.major,
+ source_metadata.version.minor,
+ source_metadata.version.hotfix,
+ source_metadata.version.build);
+
+ ret = compare_cse_version(&source_metadata.version, cse_get_rw_version(cse_bp_info));
+ if (ret == 0)
+ return CSE_UPDATE_NOT_REQUIRED;
+ else if (ret < 0)
+ return CSE_UPDATE_DOWNGRADE;
+ else
+ return CSE_UPDATE_UPGRADE;
}
static bool cse_write_rw_region(const struct region_device *target_rdev,
@@ -630,7 +638,7 @@
}
static bool cse_prep_for_rw_update(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata)
+ enum cse_update_status status)
{
/*
* To set CSE's operation mode to HMRFPO mode:
@@ -640,18 +648,19 @@
if (!cse_boot_to_ro(cse_bp_info))
return false;
- if (cse_is_downgrade_instance(cse_bp_info, source_metadata) &&
- !cse_data_clear_request(cse_bp_info)) {
- printk(BIOS_ERR, "cse_lite: CSE FW downgrade is aborted\n");
- return false;
+ if ((status == CSE_UPDATE_DOWNGRADE) || (status == CSE_UPDATE_CORRUPTED)) {
+ if (!cse_data_clear_request(cse_bp_info)) {
+ printk(BIOS_ERR, "cse_lite: CSE data clear failed!\n");
+ return false;
+ }
}
return cse_hmrfpo_enable();
}
static enum csme_failure_reason cse_trigger_fw_update(const struct cse_bp_info *cse_bp_info,
- const struct cse_rw_metadata *source_metadata,
- struct region_device *target_rdev)
+ enum cse_update_status status,
+ struct region_device *target_rdev)
{
struct region_device source_rdev;
enum csme_failure_reason rv;
@@ -666,13 +675,13 @@
return CSE_LITE_SKU_RW_BLOB_NOT_FOUND;
}
- if (!cse_verify_cbfs_rw_sha256(source_metadata->sha256, cse_cbfs_rw,
+ if (!cse_verify_cbfs_rw_sha256(source_metadata.sha256, cse_cbfs_rw,
region_device_sz(&source_rdev))) {
rv = CSE_LITE_SKU_RW_BLOB_SHA256_MISMATCH;
goto error_exit;
}
- if (!cse_prep_for_rw_update(cse_bp_info, source_metadata)) {
+ if (!cse_prep_for_rw_update(cse_bp_info, status)) {
rv = CSE_COMMUNICATION_ERROR;
goto error_exit;
}
@@ -688,26 +697,21 @@
static uint8_t cse_fw_update(const struct cse_bp_info *cse_bp_info)
{
struct region_device target_rdev;
- struct cse_rw_metadata source_metadata;
-
- /* Read CSE CBFS RW metadata */
- if (cbfs_load(CONFIG_SOC_INTEL_CSE_RW_METADATA_CBFS_NAME, &source_metadata,
- sizeof(source_metadata)) != sizeof(source_metadata)) {
- printk(BIOS_ERR, "cse_lite: Failed to get CSE CBFS RW metadata\n");
- return CSE_LITE_SKU_RW_METADATA_NOT_FOUND;
- }
+ enum cse_update_status status;
if (!cse_get_target_rdev(cse_bp_info, &target_rdev)) {
printk(BIOS_ERR, "cse_lite: Failed to get CSE RW Partition\n");
return CSE_LITE_SKU_RW_ACCESS_ERROR;
}
- if (cse_is_update_required(cse_bp_info, &source_metadata, &target_rdev)) {
- printk(BIOS_DEBUG, "cse_lite: CSE RW update is initiated\n");
- return cse_trigger_fw_update(cse_bp_info, &source_metadata, &target_rdev);
- }
+ status = cse_check_update_status(cse_bp_info, &target_rdev);
+ if (status == CSE_UPDATE_NOT_REQUIRED)
+ return CSE_NO_ERROR;
+ if (status == CSE_UPDATE_METADATA_ERROR)
+ return CSE_LITE_SKU_RW_METADATA_NOT_FOUND;
- return 0;
+ printk(BIOS_DEBUG, "cse_lite: CSE RW update is initiated\n");
+ return cse_trigger_fw_update(cse_bp_info, status, &target_rdev);
}
void cse_fw_sync(void)