cleanup: Change meaning of storage offset CONFIGs

In order to support architectures with non-contiguous writable and
protected regions, change storage offsets to be relative to writable and
protected regions, rather than relative to "the start of the region of
storage belonging to the EC".

Spec doc available at https://goo.gl/fnzTvr.

BRANCH=None
BUG=chrome-os-partner:23796
TEST=With entire patch series, on both Samus and Glados:
- Verify 'version' EC console command is correct
- Verify 'flashrom -p ec -r read.bin' reads back EC image
- Verify software sync correctly flashes both EC and PD RW images

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I796f8e7305a6336495bd256a78774595cb16a2e4
Reviewed-on: https://chromium-review.googlesource.com/297823
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 32 insertions, 9 deletions

diff --git a/common/fmap.c b/common/fmap.c
index 4fbafe6f91..35111c6d1d 100644
--- a/common/fmap.c
+++ b/common/fmap.c
@@ -7,6 +7,7 @@
 #include <stddef.h>
 
 #include "common.h"
+#include "util.h"
 #include "version.h"
 
 /* FMAP structs. See http://code.google.com/p/flashmap/wiki/FmapSpec */
@@ -20,10 +21,25 @@
  * For address containing CONFIG_PROGRAM_MEMORY_BASE (symbols in *.RO.lds.S and
  * variable), this computes the offset to the start of the image on flash.
  */
-
 #define RELATIVE_RO(addr) ((addr) - CONFIG_PROGRAM_MEMORY_BASE - \
 			   CONFIG_RO_MEM_OFF)
 
+/*
+ * All internal EC code assumes that offsets are provided relative to
+ * physical address zero of storage. In some cases, the region of storage
+ * belonging to the EC is not physical address zero - a non-zero fmap_base
+ * indicates so. Since fmap_base is not yet handled correctly by external
+ * code, we must perform the adjustment in our host command handlers -
+ * adjust all offsets so they are relative to the beginning of the storage
+ * region belonging to the EC. TODO(crbug.com/529365): Handle fmap_base
+ * correctly in flashrom, dump_fmap, etc. and remove EC_FLASH_REGION_START.
+ */
+#if CONFIG_EC_WRITABLE_STORAGE_OFF < CONFIG_EC_PROTECTED_STORAGE_OFF
+#define FMAP_REGION_START CONFIG_EC_WRITABLE_STORAGE_OFF
+#else
+#define FMAP_REGION_START CONFIG_EC_PROTECTED_STORAGE_OFF
+#endif
+
 struct fmap_header {
 	char        fmap_signature[FMAP_SIGNATURE_SIZE];
 	uint8_t     fmap_ver_major;
@@ -71,14 +87,16 @@ const struct _ec_fmap {
 			 * volatile data (ex, calibration results).
 			 */
 			.area_name = "EC_RO",
-			.area_offset = CONFIG_RO_STORAGE_OFF,
+			.area_offset = CONFIG_EC_PROTECTED_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RO_STORAGE_OFF,
 			.area_size = CONFIG_RO_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 		{
 			/* (Optional) RO firmware code. */
 			.area_name = "FR_MAIN",
-			.area_offset = CONFIG_RO_STORAGE_OFF,
+			.area_offset = CONFIG_EC_PROTECTED_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RO_STORAGE_OFF,
 			.area_size = CONFIG_RO_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
@@ -88,7 +106,8 @@ const struct _ec_fmap {
 			 * ASCII, and padded with \0.
 			 */
 			.area_name = "RO_FRID",
-			.area_offset = CONFIG_RO_STORAGE_OFF +
+			.area_offset = CONFIG_EC_PROTECTED_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RO_STORAGE_OFF +
 				RELATIVE_RO((uint32_t)__version_struct_offset) +
 				offsetof(struct version_struct,  version),
 			.area_size = sizeof(version_data.version),
@@ -98,7 +117,8 @@ const struct _ec_fmap {
 		/* Other RO stuff: FMAP, WP, KEYS, etc. */
 		{
 			.area_name = "FMAP",
-			.area_offset = CONFIG_RO_STORAGE_OFF +
+			.area_offset = CONFIG_EC_PROTECTED_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RO_STORAGE_OFF +
 				RELATIVE_RO((uint32_t)&ec_fmap),
 			.area_size = sizeof(ec_fmap),
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
@@ -110,8 +130,9 @@ const struct _ec_fmap {
 			 * EC_RO and aligned to hardware specification.
 			 */
 			.area_name = "WP_RO",
-			.area_offset = CONFIG_WP_OFF,
-			.area_size = CONFIG_WP_SIZE,
+			.area_offset = CONFIG_WP_STORAGE_OFF -
+				       FMAP_REGION_START,
+			.area_size = CONFIG_WP_STORAGE_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
 
@@ -119,7 +140,8 @@ const struct _ec_fmap {
 		{
 			 /* The range of RW firmware to be auto-updated. */
 			.area_name = "EC_RW",
-			.area_offset = CONFIG_RW_STORAGE_OFF,
+			.area_offset = CONFIG_EC_WRITABLE_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RW_STORAGE_OFF,
 			.area_size = CONFIG_RW_SIZE,
 			.area_flags = FMAP_AREA_STATIC | FMAP_AREA_RO,
 		},
@@ -132,7 +154,8 @@ const struct _ec_fmap {
 			 * accomodate image asymmetry.
 			 */
 			.area_name = "RW_FWID",
-			.area_offset = CONFIG_RW_STORAGE_OFF +
+			.area_offset = CONFIG_EC_WRITABLE_STORAGE_OFF -
+				FMAP_REGION_START + CONFIG_RW_STORAGE_OFF +
 				RELATIVE_RO((uint32_t)__version_struct_offset) +
 				offsetof(struct version_struct,  version),
 			.area_size = sizeof(version_data.version),