libpayload: Add support for handling fmaps

They will become more common soon, so better support them now.

Change-Id: I2b16e1bb7707fe8410365877524ff359aeefc161
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10868
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

payloads/libpayload/libc/Makefile.inc

@@ -38,6 +38,7 @@ libc-$(CONFIG_LP_LIBC) += qsort.c
 libc-$(CONFIG_LP_LIBC) += hexdump.c
 libc-$(CONFIG_LP_LIBC) += die.c
 libc-$(CONFIG_LP_LIBC) += coreboot.c
+libc-$(CONFIG_LP_LIBC) += fmap.c
 
 ifeq ($(CONFIG_LP_ARCH_MIPS),y)
 libc-$(CONFIG_LP_LIBC) += 64bit_div.c

payloads/libpayload/libc/fmap.c

@@ -0,0 +1,84 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2015 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <libpayload-config.h>
+#include <libpayload.h>
+#include <coreboot_tables.h>
+#include <cbfs.h>
+#include <fmap_serialized.h>
+#include <stdint.h>
+
+int fmap_region_by_name(const uint32_t fmap_offset, const char * const name,
+			uint32_t * const offset, uint32_t * const size)
+{
+	int i;
+
+	struct fmap *fmap;
+	struct fmap fmap_head;
+	struct cbfs_media default_media;
+	struct cbfs_media *media = &default_media;
+
+	if (init_default_cbfs_media(media) != 0)
+		return -1;
+
+	media->open(media);
+
+	if (!media->read(media, &fmap_head, fmap_offset, sizeof(fmap_head)))
+		return -1;
+
+	if (memcmp(fmap_head.signature, FMAP_SIGNATURE, sizeof(fmap_head.signature))) {
+		return -1;
+	}
+
+	int fmap_size = sizeof(*fmap) +
+		fmap_head.nareas * sizeof(struct fmap_area);
+
+	fmap = malloc(fmap_size);
+	if (!fmap)
+		return -1;
+
+	if (!media->read(media, fmap, fmap_offset, fmap_size))
+		goto err;
+
+	media->close(media);
+
+	for (i = 0; i < fmap->nareas; i++) {
+		if (strcmp((const char *)fmap->areas[i].name, name) != 0)
+			continue;
+		if (offset)
+			*offset = fmap->areas[i].offset;
+		if (size)
+			*size = fmap->areas[i].size;
+		free(fmap);
+		return 0;
+	}
+err:
+	free(fmap);
+	return -1;
+}