futility: update: load quirks from firmware image CBFS file

The firmware updater now looks at CBFS 'FW_MAIN_A' (RW A) and if a text
file 'updater_quirks' is found, the contents will be fetched to setup
default quirks.

This helps sharing same customization across multiple firmware images
(for different models) shared by same unibuild OS image.  Without that,
we have to maintain a large list of hard-coded model names in firmware
updater source.

BRANCH=none
BUG=b:169284414
TEST=make runtests

Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Change-Id: I938bffe9f16bc3adee0dc3efb6976efe581c6d8c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2426093
Reviewed-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2488672
Reviewed-by: Evan Green <evgreen@chromium.org>
Commit-Queue: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>

4 files changed, 75 insertions, 7 deletions

diff --git a/futility/updater.c b/futility/updater.c
index fd13bb8b..71a498e3 100644
--- a/futility/updater.c
+++ b/futility/updater.c
@@ -1288,10 +1288,15 @@ static int updater_setup_quirks(struct updater_config *cfg,
 				const struct updater_config_arguments *arg)
 {
 	int errorcnt = 0;
-	const char *quirks = updater_get_default_quirks(cfg);
+	const char *model_quirks = updater_get_model_quirks(cfg);
+	char *cbfs_quirks = updater_get_cbfs_quirks(cfg);
 
-	if (quirks)
-		errorcnt += !!setup_config_quirks(quirks, cfg);
+	if (model_quirks)
+		errorcnt += !!setup_config_quirks(model_quirks, cfg);
+	if (cbfs_quirks) {
+		errorcnt += !!setup_config_quirks(cbfs_quirks, cfg);
+		free(cbfs_quirks);
+	}
 	if (arg->quirks)
 		errorcnt += !!setup_config_quirks(arg->quirks, cfg);
 	return errorcnt;
diff --git a/futility/updater.h b/futility/updater.h
index 3ed8039c..a4f55806 100644
--- a/futility/updater.h
+++ b/futility/updater.h
@@ -175,10 +175,16 @@ int get_config_quirk(enum quirk_types quirk, const struct updater_config *cfg);
 int get_system_property(enum system_property_type property_type,
 			struct updater_config *cfg);
 /*
- * Gets the default quirk config string for target image.
+ * Gets the default quirk config string from target image name.
  * Returns a string (in same format as --quirks) to load or NULL if no quirks.
  */
-const char * const updater_get_default_quirks(struct updater_config *cfg);
+const char * const updater_get_model_quirks(struct updater_config *cfg);
+
+/*
+ * Gets the quirk config string from target image CBFS.
+ * Returns a string (in same format as --quirks) to load or NULL if no quirks.
+ */
+char * updater_get_cbfs_quirks(struct updater_config *cfg);
 
 /*
  * Overrides signature id if the device was shipped with known
diff --git a/futility/updater_quirks.c b/futility/updater_quirks.c
index e4056b05..b3dea936 100644
--- a/futility/updater_quirks.c
+++ b/futility/updater_quirks.c
@@ -476,10 +476,10 @@ void updater_register_quirks(struct updater_config *cfg)
 }
 
 /*
- * Gets the default quirk config string for target image.
+ * Gets the default quirk config string from target image name.
  * Returns a string (in same format as --quirks) to load or NULL if no quirks.
  */
-const char * const updater_get_default_quirks(struct updater_config *cfg)
+const char * const updater_get_model_quirks(struct updater_config *cfg)
 {
 	const char *pattern = cfg->image.ro_version;
 	int i;
@@ -500,6 +500,51 @@ const char * const updater_get_default_quirks(struct updater_config *cfg)
 }
 
 /*
+ * Gets the quirk config string from target image CBFS.
+ * Returns a string (in same format as --quirks) to load or NULL if no quirks.
+ */
+char *updater_get_cbfs_quirks(struct updater_config *cfg)
+{
+	const char *entry_name = "updater_quirks";
+	const char *cbfs_region = "FW_MAIN_A";
+	struct firmware_section cbfs_section;
+
+	/* Before invoking cbfstool, try to search for CBFS file name. */
+	find_firmware_section(&cbfs_section, &cfg->image, cbfs_region);
+	if (!cbfs_section.size || !memmem(cbfs_section.data, cbfs_section.size,
+					  entry_name, strlen(entry_name))) {
+		if (!cbfs_section.size)
+			VB2_DEBUG("Missing region: %s\n", cbfs_region);
+		else
+			VB2_DEBUG("Cannot find entry: %s\n", entry_name);
+		return NULL;
+	}
+
+	const char *tmp_path = get_firmware_image_temp_file(
+			&cfg->image, &cfg->tempfiles);
+	uint8_t *data = NULL;
+	uint32_t size = 0;
+
+	/* Although the name exists, it may not be a real file. */
+	if (!cbfs_file_exists(tmp_path, cbfs_region, entry_name)) {
+		VB2_DEBUG("Found string '%s' but not a file.\n", entry_name);
+		return NULL;
+	}
+
+	VB2_DEBUG("Found %s from CBFS %s\n", entry_name, cbfs_region);
+	tmp_path = cbfs_extract_file(tmp_path, cbfs_region, entry_name,
+				     &cfg->tempfiles);
+	if (!tmp_path ||
+	    vb2_read_file(tmp_path, &data, &size) != VB2_SUCCESS) {
+		ERROR("Failed to read [%s] from CBFS [%s].\n",
+		      entry_name, cbfs_region);
+		return NULL;
+	}
+	VB2_DEBUG("Got quirks (%u bytes): %s\n", size, data);
+	return (char *)data;
+}
+
+/*
  * Overrides signature id if the device was shipped with known
  * special rootkey.
  */
diff --git a/tests/futility/test_update.sh b/tests/futility/test_update.sh
index 655bab4a..ae4a3624 100755
--- a/tests/futility/test_update.sh
+++ b/tests/futility/test_update.sh
@@ -480,4 +480,16 @@ if type cbfstool >/dev/null 2>&1; then
 		"${TMP}.from.smm" "${TMP}.expected.full_smm" \
 		-i "${TO_IMAGE}" --wp=0 --sys_props 0,0x10001,1 \
 		--quirks eve_smm_store
+
+	echo "min_platform_version=3" >"${TMP}.quirk"
+	cp -f "${TO_IMAGE}" "${TO_IMAGE}.quirk"
+	${FUTILITY} dump_fmap -x "${TO_IMAGE}" "BOOT_STUB:${TMP}.cbfs"
+	# Create a fake CBFS using FW_MAIN_A size.
+	truncate -s $((0x000dffc0)) "${TMP}.cbfs"
+	${FUTILITY} load_fmap "${TO_IMAGE}.quirk" "FW_MAIN_A:${TMP}.cbfs"
+	cbfstool "${TO_IMAGE}.quirk" add -r FW_MAIN_A -n updater_quirks \
+		-f "${TMP}.quirk" -t raw
+	test_update "Full update (failure by CBFS quirks)" \
+		"${FROM_IMAGE}" "!Need platform version >= 3 (current is 2)" \
+		-i "${TO_IMAGE}.quirk" --wp=0 --sys_props 0,0x10001,1,2
 fi