layout: Hoist get_region_range() into libflashrom API

While using the libflashrom API to read specific regions
there is no currently no general way to find the offset
into the read buffer of the expected region.

flashrom_layout_include_region() probably should have
returned the region offset and size if it was included.
However to avoid a change in API signature we can instead
hoist up get_region_range() into the API to be called after.

BUG=b:207808292
TEST=`make` && tested in porting cbfstool use-case.

Change-Id: I8cf95b5eaec943a51d0ea668f26a56bf6d6b4446
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/60881
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sam McNally <sammc@google.com>

cli_classic.c

@@ -782,7 +782,7 @@ int main(int argc, char *argv[])
 	}
 
 	if (set_wp_region && wp_region) {
-		if (get_region_range(layout, wp_region, &wp_start, &wp_len)) {
+		if (flashrom_layout_get_region_range(layout, wp_region, &wp_start, &wp_len)) {
 			ret = 1;
 			goto out_release;
 		}

layout.c

@@ -188,18 +188,6 @@ static int find_romentry(struct flashrom_layout *const l, char *name, char *file
 	return 0;
 }
 
-int get_region_range(struct flashrom_layout *const l, const char *name,
-		     unsigned int *start, unsigned int *len)
-{
-	const struct romentry *const entry = _layout_entry_by_name(l, name);
-	if (entry) {
-		*start = entry->start;
-		*len = entry->end - entry->start + 1;
-		return 0;
-	}
-	return 1;
-}
-
 /* process -i arguments
  * returns 0 to indicate success, >0 to indicate failure
  */
@@ -444,6 +432,29 @@ int flashrom_layout_include_region(struct flashrom_layout *const layout, const c
 	return include_region(layout, name, NULL);
 }
 
+/**
+ * @brief Get given region's offset and length.
+ *
+ * @param layout The layout to alter.
+ * @param name   The name of the region.
+ * @param start  The start address to be written.
+ * @param len    The length of the region to be written.
+ *
+ * @return 0 on success,
+ *         1 if the given name can't be found.
+ */
+int flashrom_layout_get_region_range(struct flashrom_layout *const l, const char *name,
+			      unsigned int *start, unsigned int *len)
+{
+	const struct romentry *const entry = _layout_entry_by_name(l, name);
+	if (entry) {
+		*start = entry->start;
+		*len = entry->end - entry->start + 1;
+		return 0;
+	}
+	return 1;
+}
+
 /**
  * @brief Free a layout.
  *

layout.h

@@ -59,8 +59,6 @@ int register_include_arg(struct layout_include_args **, const char *arg);
 int process_include_args(struct flashrom_layout *, const struct layout_include_args *);
 void cleanup_include_args(struct layout_include_args **);
 
-int get_region_range(struct flashrom_layout *, const char *name,
-		     unsigned int *start, unsigned int *len);
 const struct romentry *layout_next_included_region(const struct flashrom_layout *, chipoff_t);
 const struct romentry *layout_next_included(const struct flashrom_layout *, const struct romentry *);
 const struct romentry *layout_next(const struct flashrom_layout *, const struct romentry *);

libflashrom.h

@@ -114,6 +114,8 @@ int flashrom_layout_read_fmap_from_buffer(struct flashrom_layout **layout,
 		struct flashrom_flashctx *, const uint8_t *buf, size_t len);
 int flashrom_layout_add_region(struct flashrom_layout *, size_t start, size_t end, const char *name);
 int flashrom_layout_include_region(struct flashrom_layout *, const char *name);
+int flashrom_layout_get_region_range(struct flashrom_layout *, const char *name,
+		     unsigned int *start, unsigned int *len);
 void flashrom_layout_release(struct flashrom_layout *);
 void flashrom_layout_set(struct flashrom_flashctx *, const struct flashrom_layout *);
 

libflashrom.map

@@ -14,6 +14,7 @@ LIBFLASHROM_1.0 {
     flashrom_image_verify;
     flashrom_image_write;
     flashrom_init;
+    flashrom_layout_get_region_range;
     flashrom_layout_include_region;
     flashrom_layout_read_fmap_from_buffer;
     flashrom_layout_read_fmap_from_rom;

tests/layout.c

@@ -121,7 +121,7 @@ void layout_pass_sanity_checks_test_success(void **state)
 	printf("done\n");
 
 	printf("Asserting region range... ");
-	get_region_range(layout, "region", &start, &len);
+	flashrom_layout_get_region_range(layout, "region", &start, &len);
 	assert_int_equal(start, region_start);
 	assert_int_equal(len, region_end - region_start + 1);
 	printf("done\n");