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, 31 insertions, 10 deletions

diff --git a/common/flash.c b/common/flash.c
index b2c3847e60..72dbe35843 100644
--- a/common/flash.c
+++ b/common/flash.c
@@ -722,11 +722,24 @@ DECLARE_CONSOLE_COMMAND(flashwp, command_flash_wp,
 /*****************************************************************************/
 /* Host commands */
 
+/*
+ * 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.
+ */
+#define EC_FLASH_REGION_START MIN(CONFIG_EC_PROTECTED_STORAGE_OFF, \
+				  CONFIG_EC_WRITABLE_STORAGE_OFF)
+
 static int flash_command_get_info(struct host_cmd_handler_args *args)
 {
 	struct ec_response_flash_info_1 *r = args->response;
 
-	r->flash_size = CONFIG_FLASH_SIZE;
+	r->flash_size = CONFIG_FLASH_SIZE - EC_FLASH_REGION_START;
 	r->write_block_size = CONFIG_FLASH_WRITE_SIZE;
 	r->erase_block_size = CONFIG_FLASH_ERASE_SIZE;
 	r->protect_block_size = CONFIG_FLASH_BANK_SIZE;
@@ -772,11 +785,12 @@ DECLARE_HOST_COMMAND(EC_CMD_FLASH_INFO,
 static int flash_command_read(struct host_cmd_handler_args *args)
 {
 	const struct ec_params_flash_read *p = args->params;
+	uint32_t offset = p->offset + EC_FLASH_REGION_START;
 
 	if (p->size > args->response_max)
 		return EC_RES_OVERFLOW;
 
-	if (flash_read(p->offset, p->size, args->response))
+	if (flash_read(offset, p->size, args->response))
 		return EC_RES_ERROR;
 
 	args->response_size = p->size;
@@ -796,6 +810,7 @@ DECLARE_HOST_COMMAND(EC_CMD_FLASH_READ,
 static int flash_command_write(struct host_cmd_handler_args *args)
 {
 	const struct ec_params_flash_write *p = args->params;
+	uint32_t offset = p->offset + EC_FLASH_REGION_START;
 
 	if (flash_get_protect() & EC_FLASH_PROTECT_ALL_NOW)
 		return EC_RES_ACCESS_DENIED;
@@ -803,10 +818,10 @@ static int flash_command_write(struct host_cmd_handler_args *args)
 	if (p->size + sizeof(*p) > args->params_size)
 		return EC_RES_INVALID_PARAM;
 
-	if (system_unsafe_to_overwrite(p->offset, p->size))
+	if (system_unsafe_to_overwrite(offset, p->size))
 		return EC_RES_ACCESS_DENIED;
 
-	if (flash_write(p->offset, p->size, (const uint8_t *)(p + 1)))
+	if (flash_write(offset, p->size, (const uint8_t *)(p + 1)))
 		return EC_RES_ERROR;
 
 	return EC_RES_SUCCESS;
@@ -818,11 +833,12 @@ DECLARE_HOST_COMMAND(EC_CMD_FLASH_WRITE,
 static int flash_command_erase(struct host_cmd_handler_args *args)
 {
 	const struct ec_params_flash_erase *p = args->params;
+	uint32_t offset = p->offset + EC_FLASH_REGION_START;
 
 	if (flash_get_protect() & EC_FLASH_PROTECT_ALL_NOW)
 		return EC_RES_ACCESS_DENIED;
 
-	if (system_unsafe_to_overwrite(p->offset, p->size))
+	if (system_unsafe_to_overwrite(offset, p->size))
 		return EC_RES_ACCESS_DENIED;
 
 	/* Indicate that we might be a while */
@@ -830,7 +846,7 @@ static int flash_command_erase(struct host_cmd_handler_args *args)
 	args->result = EC_RES_IN_PROGRESS;
 	host_send_response(args);
 #endif
-	if (flash_erase(p->offset, p->size))
+	if (flash_erase(offset, p->size))
 		return EC_RES_ERROR;
 
 	return EC_RES_SUCCESS;
@@ -890,16 +906,21 @@ static int flash_command_region_info(struct host_cmd_handler_args *args)
 
 	switch (p->region) {
 	case EC_FLASH_REGION_RO:
-		r->offset = CONFIG_RO_STORAGE_OFF;
+		r->offset = CONFIG_EC_PROTECTED_STORAGE_OFF +
+			    CONFIG_RO_STORAGE_OFF -
+			    EC_FLASH_REGION_START;
 		r->size = CONFIG_RO_SIZE;
 		break;
 	case EC_FLASH_REGION_RW:
-		r->offset = CONFIG_RW_STORAGE_OFF;
+		r->offset = CONFIG_EC_WRITABLE_STORAGE_OFF +
+			    CONFIG_RW_STORAGE_OFF -
+			    EC_FLASH_REGION_START;
 		r->size = CONFIG_RW_SIZE;
 		break;
 	case EC_FLASH_REGION_WP_RO:
-		r->offset = CONFIG_WP_OFF;
-		r->size = CONFIG_WP_SIZE;
+		r->offset = CONFIG_WP_STORAGE_OFF -
+			    EC_FLASH_REGION_START;
+		r->size = CONFIG_WP_STORAGE_SIZE;
 		break;
 	default:
 		return EC_RES_INVALID_PARAM;