EFS: Add support for early firmware selection

Chromebox ECs performs EFS: verifying firmware before the AP boots.
This patch updates host commands which are required for the EFS.

The change includes:
* Update EC_CMD_FLASH_REGION_INFO to accept EC_FLASH_REGION_UPDATE
* Update EC_CMD_VBOOT_HASH to accept EC_VBOOT_HASH_OFFSET_UPDATE

When EC_FLASHS_REGION_UPDATE is specified, EC_CMD_FLASH_REGION_INFO
returns the slot which currently is not hosting a running RW copy.

When EC_VBOOT_HASH_OFFSET_UPDATE is specified, EC_CMD_VBOOT_HASH
computs the hash of the update slot. This hash covers the entire
region, including the signature at the end.

This patch undefines CONFIG_CMD_USBMUX and CONFIG_CMD_TYPEC
for gru to create space.

BUG=b:65028930
BRANCH=none
CQ-DEPEND=CL:648071
TEST=On Fizz, verify:
1. RW_B is old and updated by soft sync. RW_B is activated and
   executed after reboot. System continues to boot to OS.
2. RW_A is old and updated by soft sync. RW_A is activated and
   executed after reboot. System continues to boot to OS.

Change-Id: I9ece907b764d07ce94054ba27996e048c665a80a
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/648448

1 files changed, 35 insertions, 6 deletions

diff --git a/common/system.c b/common/system.c
index 07d43da38b..62c036baf9 100644
--- a/common/system.c
+++ b/common/system.c
@@ -420,14 +420,19 @@ test_mockable int system_unsafe_to_overwrite(uint32_t offset, uint32_t size)
 		r_size = CONFIG_RO_SIZE;
 		break;
 	case SYSTEM_IMAGE_RW:
-		r_offset = CONFIG_EC_WRITABLE_STORAGE_OFF +
-			   CONFIG_RW_STORAGE_OFF;
+		r_offset = flash_get_rw_offset(FLASH_RW_SLOT_A);
 		r_size = CONFIG_RW_SIZE;
 #ifdef CONFIG_RWSIG
 		/* Allow RW sig to be overwritten */
 		r_size -= CONFIG_RW_SIG_SIZE;
 #endif
 		break;
+#ifdef CONFIG_VBOOT_EFS
+	case SYSTEM_IMAGE_RW_B:
+		r_offset = flash_get_rw_offset(FLASH_RW_SLOT_B);
+		r_size = CONFIG_RW_SIZE - CONFIG_RW_SIG_SIZE;
+		break;
+#endif
 	default:
 		return 0;
 	}
@@ -614,6 +619,19 @@ int system_run_image_copy(enum system_image_copy_t copy)
 	return EC_ERROR_UNKNOWN;
 }
 
+/*
+ * This is defined in system.c instead of flash.c because it's called even
+ * on the boards which don't include flash.o. (e.g. hadoken, stm32l476g-eval)
+ */
+uint32_t flash_get_rw_offset(enum flash_rw_slot slot)
+{
+#ifdef CONFIG_VBOOT_EFS
+	if (slot == FLASH_RW_SLOT_B)
+		return CONFIG_EC_WRITABLE_STORAGE_OFF + CONFIG_RW_B_STORAGE_OFF;
+#endif
+	return CONFIG_EC_WRITABLE_STORAGE_OFF + CONFIG_RW_STORAGE_OFF;
+}
+
 static const struct image_data *system_get_image_data(
 					enum system_image_copy_t copy)
 {
@@ -639,9 +657,17 @@ static const struct image_data *system_get_image_data(
 	 * Read the version information from the proper location
 	 * on storage.
 	 */
-	addr += (is_rw_image(copy)) ?
-		CONFIG_EC_WRITABLE_STORAGE_OFF + CONFIG_RW_STORAGE_OFF :
-		CONFIG_EC_PROTECTED_STORAGE_OFF + CONFIG_RO_STORAGE_OFF;
+	switch (copy) {
+	case SYSTEM_IMAGE_RW:
+		addr += flash_get_rw_offset(FLASH_RW_SLOT_A);
+		break;
+	case SYSTEM_IMAGE_RW_B:
+		addr += flash_get_rw_offset(FLASH_RW_SLOT_B);
+		break;
+	default:
+		addr += CONFIG_EC_PROTECTED_STORAGE_OFF + CONFIG_RO_STORAGE_OFF;
+		break;
+	}
 
 #ifdef CONFIG_MAPPED_STORAGE
 	addr += CONFIG_MAPPED_STORAGE_BASE;
@@ -1198,10 +1224,12 @@ DECLARE_CONSOLE_COMMAND(sysrq, command_sysrq,
 static int host_command_get_version(struct host_cmd_handler_args *args)
 {
 	struct ec_response_get_version *r = args->response;
+	enum flash_rw_slot active_slot = flash_get_active_slot();
 
 	strzcpy(r->version_string_ro, system_get_version(SYSTEM_IMAGE_RO),
 		sizeof(r->version_string_ro));
-	strzcpy(r->version_string_rw, system_get_version(SYSTEM_IMAGE_RW),
+	strzcpy(r->version_string_rw,
+		system_get_version(flash_slot_to_image(active_slot)),
 		sizeof(r->version_string_rw));
 
 	switch (system_get_image_copy()) {
@@ -1209,6 +1237,7 @@ static int host_command_get_version(struct host_cmd_handler_args *args)
 		r->current_image = EC_IMAGE_RO;
 		break;
 	case SYSTEM_IMAGE_RW:
+	case SYSTEM_IMAGE_RW_B:
 		r->current_image = EC_IMAGE_RW;
 		break;
 	default: