util/smmstoretool: support processing ROMs

Input file is parsed for FMAP and SMMSTORE region which is used if
found.  Otherwise, the whole file is assumed to be the region.  Passing
an image with FMAP that lacks SMMSTORER is an error.

Change-Id: Ieab555d7bbcfa4dadf6a5070d1297acd737440fb
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80903
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

5 files changed, 59 insertions, 17 deletions

diff --git a/Documentation/util/smmstoretool/index.md b/Documentation/util/smmstoretool/index.md
index f7af60579d..5be6ffc79b 100644
--- a/Documentation/util/smmstoretool/index.md
+++ b/Documentation/util/smmstoretool/index.md
@@ -4,13 +4,20 @@ Offline SMMSTORE variable modification tool.
 
 ## Operation
 
+### File formats
+
+To discover SMMSTORE, the tool first looks for FMAP header and, if found, for
+SMMSTORE region.  If FMAP is found but it has no SMMSTORE region, that's an
+error.  If there is no FMAP, the whole file is assumed to be SMMSTORE
+region (e.g., extracted via `cbfstool`).
+
 ### Storage initialization
 
 If SMMSTORE presence isn't detected and an update operation is requested, the
-store spanning the whole file is created automatically.  Size of the store file
-must be a multiple of 64 KiB (block size in version 2 of SMMSTORE protocol),
-the variable storage itself will be 64 KiB in size.  That's the way EDK2 makes
-use of it.
+store spanning the whole region is created automatically.  Size of the store
+region must be a multiple of 64 KiB (block size in version 2 of SMMSTORE
+protocol), the variable storage itself will be 64 KiB in size.  That's the way
+EDK2 makes use of it.
 
 Unlike online editing which mostly appends new variable entries each storage
 update with this tool drops all deleted or incomplete entries.
@@ -28,7 +35,7 @@ Start with:
 
 ```
 $ smmstoretool -h
-Usage: smmstoretool smm-store-file sub-command
+Usage: smmstoretool smm-store-file|rom sub-command
        smmstoretool -h|--help
 
 Sub-commands:
@@ -58,7 +65,8 @@ to typical configuration values are supported:
 
 ## Examples
 
-`SMMSTORE` is the name of a file containing SMMSTORE data.
+`SMMSTORE` is the name of a file containing SMMSTORE data or a full ROM image
+with FMAP that includes SMMSTORE region.
 
 ### Variable listing
 
@@ -111,9 +119,13 @@ $ smmstoretool SMMSTORE remove -g dasharo -n NetworkBoot
 If one edits a newly generated Dasharo `coreboot.rom`:
 
 ```bash
+# editing exported storage
 cbfstool coreboot.rom read -r SMMSTORE -f SMMSTORE
 smmstoretool SMMSTORE set -g dasharo -n NetworkBoot -t bool -v true
 cbfstool coreboot.rom write -r SMMSTORE -f SMMSTORE
+
+# editing in-place storage
+smmstoretool coreboot.rom set -g dasharo -n NetworkBoot -t bool -v true
 ```
 
 On the first boot, "Network Boot" setting will already be enabled.
diff --git a/util/smmstoretool/Makefile b/util/smmstoretool/Makefile
index 78b77caa2d..d73c25165a 100644
--- a/util/smmstoretool/Makefile
+++ b/util/smmstoretool/Makefile
@@ -14,6 +14,7 @@ HOSTCFLAGS ?= $(CFLAGS)
 HOSTCFLAGS += -Wall -Wextra -MMD -MP -O3
 HOSTCFLAGS += -I $(ROOT)/commonlib/bsd/include
 HOSTCFLAGS += -I $(ROOT)/vendorcode/intel/edk2/
+HOSTCFLAGS += -I $(TOP)/util/cbfstool/flashmap/
 HOSTCFLAGS += -I $(MDE)
 
 HOSTLDFLAGS ?= $(LDFLAGS)
@@ -27,7 +28,10 @@ else
     $(error Unsupported machine: '$(MACHINE)')
 endif
 
+# there files are in this directory
 SRC := data.c fv.c guids.c main.c storage.c utils.c vs.c
+# and these are in $(TOP)/util/cbfstool/flashmap/
+SRC += fmap.c kv_pair.c valstr.c
 
 OBJ := $(SRC:.c=.o)
 DEP := $(SRC:.c=.o.d)
@@ -53,4 +57,7 @@ $(PRG): $(OBJ)
 %.o: %.c
 	$(HOSTCC) $(HOSTCFLAGS) -c -o $@ -MF $@.d $<
 
+%.o: $(TOP)/util/cbfstool/flashmap/%.c
+	$(HOSTCC) $(HOSTCFLAGS) -c -o $@ -MF $@.d $<
+
 -include $(DEP)
diff --git a/util/smmstoretool/main.c b/util/smmstoretool/main.c
index eff5d9c02b..4857b624ba 100644
--- a/util/smmstoretool/main.c
+++ b/util/smmstoretool/main.c
@@ -77,7 +77,7 @@ static const struct subcommand_t sub_commands[] = {
 
 static const int sub_command_count = ARRAY_SIZE(sub_commands);
 
-static const char *USAGE_FMT = "Usage: %s smm-store-file sub-command\n"
+static const char *USAGE_FMT = "Usage: %s smm-store-file|rom sub-command\n"
 			       "       %s -h|--help\n";
 
 static const char *program_name;
@@ -131,7 +131,7 @@ static void print_types(FILE *f)
 static void help_set(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "Create or update a variable:\n");
-	fprintf(f, "  %s smm-store-file %s \\\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s \\\n", program_name, info->name);
 	fprintf(f, "      -g vendor-guid \\\n");
 	fprintf(f, "      -n variable-name \\\n");
 	fprintf(f, "      -t variable-type \\\n");
@@ -229,7 +229,7 @@ static int process_set(int argc, char *argv[], const char store_file[])
 static void help_list(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "List variables in the store:\n");
-	fprintf(f, "  %s smm-store-file %s\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s\n", program_name, info->name);
 }
 
 static int process_list(int argc, char *argv[], const char store_file[])
@@ -261,7 +261,7 @@ static int process_list(int argc, char *argv[], const char store_file[])
 static void help_get(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "Read variable's value:\n");
-	fprintf(f, "  %s smm-store-file %s \\\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s \\\n", program_name, info->name);
 	fprintf(f, "      -g vendor-guid \\\n");
 	fprintf(f, "      -n variable-name \\\n");
 	fprintf(f, "      -t variable-type\n");
@@ -334,10 +334,10 @@ static int process_get(int argc, char *argv[], const char store_file[])
 static void help_help(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "Display generic help:\n");
-	fprintf(f, "  %s smm-store-file %s\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s\n", program_name, info->name);
 	fprintf(f, "\n");
 	fprintf(f, "Display sub-command help:\n");
-	fprintf(f, "  %s smm-store-file %s sub-command\n",
+	fprintf(f, "  %s smm-store-file|rom %s sub-command\n",
 		program_name, info->name);
 }
 
@@ -375,7 +375,7 @@ static int process_help(int argc, char *argv[], const char store_file[])
 static void help_remove(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "Remove a variable:\n");
-	fprintf(f, "  %s smm-store-file %s \\\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s \\\n", program_name, info->name);
 	fprintf(f, "      -g vendor-guid \\\n");
 	fprintf(f, "      -n variable-name\n");
 }
@@ -432,7 +432,7 @@ static int process_remove(int argc, char *argv[], const char store_file[])
 static void help_guids(FILE *f, const struct subcommand_t *info)
 {
 	fprintf(f, "List recognized GUIDS:\n");
-	fprintf(f, "  %s smm-store-file %s\n", program_name, info->name);
+	fprintf(f, "  %s smm-store-file|rom %s\n", program_name, info->name);
 }
 
 static int process_guids(int argc, char *argv[], const char store_file[])
diff --git a/util/smmstoretool/storage.c b/util/smmstoretool/storage.c
index abc6840b67..8a02384108 100644
--- a/util/smmstoretool/storage.c
+++ b/util/smmstoretool/storage.c
@@ -5,6 +5,9 @@
 #include <assert.h>
 #include <stdio.h>
 
+#include "commonlib/bsd/compiler.h"
+#include "fmap.h"
+
 #include "fv.h"
 #include "utils.h"
 
@@ -19,8 +22,27 @@ bool storage_open(const char store_file[], struct storage_t *storage, bool rw)
 		return false;
 	}
 
+	/* If we won't find FMAP with SMMSTORE, use the whole file, but fail if
+	 * FMAP is there without SMMSTORE. */
+	storage->region = storage->file;
+
+	long fmap_offset = fmap_find(storage->file.start, storage->file.length);
+	if (fmap_offset >= 0) {
+		struct fmap *fmap = (void *)(storage->file.start + fmap_offset);
+		const struct fmap_area *area = fmap_find_area(fmap, "SMMSTORE");
+		if (area == NULL) {
+			fprintf(stderr,
+				"Found FMAP without SMMSTORE in \"%s\"\n",
+				store_file);
+			return false;
+		}
+
+		storage->region.start += area->offset;
+		storage->region.length = area->size;
+	}
+
 	bool auth_vars;
-	if (!fv_parse(storage->file, &storage->store_area, &auth_vars)) {
+	if (!fv_parse(storage->region, &storage->store_area, &auth_vars)) {
 		if (!rw) {
 			fprintf(stderr,
 				"Failed to find variable store in \"%s\"\n",
@@ -28,14 +50,14 @@ bool storage_open(const char store_file[], struct storage_t *storage, bool rw)
 			goto error;
 		}
 
-		if (!fv_init(storage->file)) {
+		if (!fv_init(storage->region)) {
 			fprintf(stderr,
 				"Failed to create variable store in \"%s\"\n",
 				store_file);
 			goto error;
 		}
 
-		if (!fv_parse(storage->file, &storage->store_area, &auth_vars)) {
+		if (!fv_parse(storage->region, &storage->store_area, &auth_vars)) {
 			fprintf(stderr,
 				"Failed to parse newly formatted store in \"%s\"\n",
 				store_file);
diff --git a/util/smmstoretool/storage.h b/util/smmstoretool/storage.h
index eb5cb08fc5..8b91713f14 100644
--- a/util/smmstoretool/storage.h
+++ b/util/smmstoretool/storage.h
@@ -9,6 +9,7 @@
 struct storage_t {
 	bool rw;
 	struct mem_range_t file;
+	struct mem_range_t region;
 	struct mem_range_t store_area;
 	struct var_store_t vs;
 };