chromeos-ec: Refine FMAP.

Make EC FMAP more compliant to existing devices (EC_RO, EC_RW, RW_FWID),
eliminating unnecessary areas (RO_SETION, EC_IMAGE), and add more detailed
comments to each area.

BUG=chrome-os-partner:11360
TEST=emerge-link chromeos-ec; dump_fmap -x ec.bin

Change-Id: I3d30d6fe0d3cee2e944009dccef488f7215b6395
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/27739

1 files changed, 33 insertions, 37 deletions

diff --git a/common/fmap.c b/common/fmap.c
index ea2b1ba93c..fb50e23dd7 100644
--- a/common/fmap.c
+++ b/common/fmap.c
@@ -40,9 +40,9 @@ typedef struct _FmapAreaHeader {
 } __packed FmapAreaHeader;
 
 #ifdef CONFIG_VBOOT_SIG
-#define NUM_EC_FMAP_AREAS 13
+#define NUM_EC_FMAP_AREAS (7 + 4)
 #else
-#define NUM_EC_FMAP_AREAS 11
+#define NUM_EC_FMAP_AREAS 7
 #endif
 
 const struct _ec_fmap {
@@ -63,19 +63,25 @@ const struct _ec_fmap {
 	{
 	/* RO Firmware */
 		{
-			.area_name = "RO_SECTION",
+			/* Range of RO firmware to be updated. Verified in
+			 * factory finalization by hash. Should not have
+			 * volatile data (ex, calibration results). */
+			.area_name = "EC_RO",
 			.area_offset = CONFIG_SECTION_RO_OFF,
 			.area_size = CONFIG_SECTION_RO_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 		{
+			/* (Optional) RO firmware boot execution code. */
 			.area_name = "BOOT_STUB",
 			.area_offset = CONFIG_FW_RO_OFF,
 			.area_size = CONFIG_FW_RO_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 		{
-			.area_name = "RO_FRID",	/* FIXME: Where is it? */
+			/* RO firmware version ID. Must be NULL terminated
+			 * ASCIIZ, and padded with \0. */
+			.area_name = "RO_FRID",
 			.area_offset = CONFIG_FW_RO_OFF +
 				(uint32_t)__version_struct_offset +
 				offsetof(struct version_struct,  version),
@@ -83,15 +89,7 @@ const struct _ec_fmap {
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 
-		/* Other RO stuff: FMAP, GBB, etc. */
-#ifdef CONFIG_VBOOT_SIG
-		{
-			.area_name = "ROOT_KEY",
-			.area_offset = CONFIG_VBOOT_ROOTKEY_OFF,
-			.area_size = CONFIG_VBOOT_ROOTKEY_SIZE,
-			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
-		},
-#endif
+		/* Other RO stuff: FMAP, WP, KEYS, etc. */
 		{
 			.area_name = "FMAP",
 			.area_offset = (uint32_t)&ec_fmap,
@@ -99,36 +97,43 @@ const struct _ec_fmap {
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 		{
-			/* A dummy region to identify it as EC firmware */
-			.area_name = "EC_IMAGE",
+			/* The range for write protection, for factory
+			 * finalization.  Should include (or identical to)
+			 * EC_RO and aligned to hardware specification. */
+			.area_name = "WP_RO",
 			.area_offset = CONFIG_SECTION_RO_OFF,
-			.area_size = 0, /* Always zero */
+			.area_size = CONFIG_SECTION_RO_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
+#ifdef CONFIG_VBOOT_SIG
 		{
-			/* The range for write protect, for lagecy firmware
-			 * updater. Should be identical to 'WP_RO'. */
-			.area_name = "EC_RO",
-			.area_offset = CONFIG_SECTION_RO_OFF,
-			.area_size = CONFIG_SECTION_RO_SIZE,
+			.area_name = "ROOT_KEY",
+			.area_offset = CONFIG_VBOOT_ROOTKEY_OFF,
+			.area_size = CONFIG_VBOOT_ROOTKEY_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
+#endif
+
+	/* RW Firmware */
 		{
-			/* The range for autoupdate to update RW */
+			 /* The range of RW firmware to be auto-updated. */
 			.area_name = "EC_RW",
 			.area_offset = CONFIG_SECTION_RW_OFF,
 			.area_size = CONFIG_SECTION_RW_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 		{
-			/* The range for write protect, for factory finalize
-			 * test case. Should be identical to 'EC_RO'. */
-			.area_name = "WP_RO",
-			.area_offset = CONFIG_SECTION_RO_OFF,
-			.area_size = CONFIG_SECTION_RO_SIZE,
-			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
+			/* RW firmware version ID. Must be NULL terminated
+			 * ASCIIZ, and padded with \0. */
+			.area_name = "RW_FWID",
+			.area_offset = CONFIG_FW_RW_OFF +
+				(uint32_t)__version_struct_offset +
+				offsetof(struct version_struct,  version),
+			.area_size = sizeof(version_data.version),
+			.area_flags = FMAP_AREA_STATIC,
 		},
 
+#ifdef CONFIG_VBOOT_SIG
 		/* Firmware A */
 		{
 			.area_name = "RW_SECTION_A",
@@ -143,15 +148,6 @@ const struct _ec_fmap {
 			.area_flags = FMAP_AREA_STATIC,
 		},
 		{
-			.area_name = "RW_FWID_A", /* FIXME: Where is it? */
-			.area_offset = CONFIG_FW_RW_OFF +
-				(uint32_t)__version_struct_offset +
-				offsetof(struct version_struct,  version),
-			.area_size = sizeof(version_data.version),
-			.area_flags = FMAP_AREA_STATIC,
-		},
-#ifdef CONFIG_VBOOT_SIG
-		{
 			.area_name = "VBLOCK_A",
 			.area_offset = CONFIG_VBLOCK_RW_OFF,
 			.area_size = CONFIG_VBLOCK_SIZE,