layout: Add capacity field

Use it to keep track of the size of the `entries` array. An interim
solution until we have dynamic allocation.

Change-Id: Ib5f431bc0a72a79a53fa1376c3417942b19dd3a0
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33516
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-by: Peter Marheine <pmarheine@chromium.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

flashrom.c

@@ -825,6 +825,7 @@ notfound:
 	/* Fill fallback layout covering the whole chip. */
 	struct single_layout *const fallback = &flash->fallback_layout;
 	fallback->base.entries		= &fallback->entry;
+	fallback->base.capacity		= 1;
 	fallback->base.num_entries	= 1;
 	fallback->entry.start		= 0;
 	fallback->entry.end		= flash->chip->total_size * 1024 - 1;

ich_descriptors.c

@@ -1295,6 +1295,7 @@ int layout_from_ich_descriptors(struct ich_layout *const layout, const void *con
 		++j;
 	}
 	layout->base.entries = layout->entries;
+	layout->base.capacity = ARRAY_SIZE(layout->entries);
 	layout->base.num_entries = j;
 	return 0;
 }

layout.c

@@ -26,7 +26,7 @@
 #include "layout.h"
 
 static struct romentry entries[MAX_ROMLAYOUT];
-static struct flashrom_layout global_layout = { entries, 0 };
+static struct flashrom_layout global_layout = { entries, MAX_ROMLAYOUT, 0 };
 
 struct flashrom_layout *get_global_layout(void)
 {
@@ -87,9 +87,9 @@ int read_romlayout(const char *name)
 	while (!feof(romlayout)) {
 		char *tstr1, *tstr2;
 
-		if (layout->num_entries >= MAX_ROMLAYOUT) {
-			msg_gerr("Maximum number of ROM images (%i) in layout "
-				 "file reached.\n", MAX_ROMLAYOUT);
+		if (layout->num_entries >= layout->capacity) {
+			msg_gerr("Maximum number of ROM images (%zu) in layout "
+				 "file reached.\n", layout->capacity);
 			goto _close_ret;
 		}
 		if (2 != fscanf(romlayout, "%255s %255s\n", tempstr, tempname))

layout.h

@@ -46,6 +46,8 @@ struct romentry {
 struct flashrom_layout {
 	/* entries store the entries specified in a layout file and associated run-time data */
 	struct romentry *entries;
+	/* the maximum number of entries */
+	size_t capacity;
 	/* the number of successfully parsed entries */
 	size_t num_entries;
 };

libflashrom.c

@@ -506,7 +506,7 @@ static int flashrom_layout_parse_fmap(struct flashrom_layout **layout,
 	if (!fmap || !l)
 		return 1;
 
-	if (l->num_entries + fmap->nareas > MAX_ROMLAYOUT) {
+	if (l->num_entries + fmap->nareas > l->capacity) {
 		msg_gerr("Cannot add fmap entries to layout - Too many entries.\n");
 		return 1;
 	}