SandyBridge/IvyBridge: Use flash map to find MRC cache

Until now, the MRC cache position and size was hard coded in Kconfig.
However, on ChromeOS devices, it should be determined by reading the
FMAP.

This patch provides a minimalistic FMAP parser (libflashmap was too
complex and OS centered) to allow reading the in-ROM flash map and
look for sections.

This will also be needed on some partner devices where coreboot will
have to find the VPD in order to set up the device's mac address
correctly.

The MRC cache implementation demonstrates how to use the FMAP parser.

Change-Id: I34964b72587443a6ca4f27407d778af8728565f8
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1701
Reviewed-by: Marc Jones <marcj303@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 126 insertions, 0 deletions

diff --git a/src/vendorcode/google/chromeos/fmap.c b/src/vendorcode/google/chromeos/fmap.c
new file mode 100644
index 0000000000..0871529a75
--- /dev/null
+++ b/src/vendorcode/google/chromeos/fmap.c
@@ -0,0 +1,126 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include <console/console.h>
+#include "fmap.h"
+
+static int fmap_try_find(void *fmap)
+{
+	if (!memcmp(fmap, FMAP_SIGNATURE,
+	    sizeof(FMAP_SIGNATURE)-1))
+		return 1;
+	return 0;
+}
+
+/* Find FMAP data structure in ROM.
+ * See http://code.google.com/p/flashmap/ for more information on FMAP.
+ */
+const struct fmap *fmap_find(void)
+{
+	const struct fmap *fmap = NULL;
+
+	/* FIXME: Get rid of the hard codes. The "easy" way would be to
+	 * do a binary search, but since ROM accesses are slow, we don't
+	 * want to spend a lot of time looking for the FMAP. An elegant
+	 * solution would be to store a pointer to the FMAP in the CBFS
+	 * master header; that would require some more changes to cbfstool
+	 * and possibly cros_bundle_firmware.
+	 * FIXME: Use CONFIG_ROMSIZE instead of CONFIG_MRC_CACHE_BASE
+	 * (and get rid of CONFIG_MRC_CACHE_BASE), once we are building
+	 * coreboot images with ME firmware etc built in instead of just
+	 * the CBFS part.
+	 */
+	if (fmap_try_find((void *)CONFIG_MRC_CACHE_BASE +
+						CONFIG_FLASHMAP_OFFSET))
+		fmap = (const struct fmap  *)(CONFIG_MRC_CACHE_BASE +
+						CONFIG_FLASHMAP_OFFSET);
+	if (fmap) {
+		printk(BIOS_DEBUG, "FMAP: Found \"%s\" version %d.%d at %p.\n",
+			fmap->name, fmap->ver_major, fmap->ver_minor, fmap);
+		printk(BIOS_DEBUG, "FMAP: base = %llx size = %x #areas = %d\n",
+			(unsigned long long)fmap->base, fmap->size,
+			fmap->nareas);
+	} else
+		printk(BIOS_DEBUG, "No FMAP found.\n");
+
+	return fmap;
+}
+
+const struct fmap_area *find_fmap_area(const struct fmap *fmap,
+							const char name[])
+{
+	const struct fmap_area *area = NULL;
+
+	if (fmap) {
+		int i;
+		for (i = 0; i < fmap->nareas; i++) {
+			if (!strcmp((const char *)fmap->areas[i].name, name)) {
+				area = &fmap->areas[i];
+				break;
+			}
+		}
+	}
+
+	if (area) {
+		printk(BIOS_DEBUG, "FMAP: area %s found\n", name);
+		printk(BIOS_DEBUG, "FMAP:   offset: %x\n", area->offset);
+		printk(BIOS_DEBUG, "FMAP:   size:   %d bytes\n", area->size);
+	} else {
+		printk(BIOS_DEBUG, "FMAP: area %s not found\n", name);
+	}
+
+	return area;
+}
+
+int find_fmap_entry(const char name[], void **pointer)
+{
+#ifndef __PRE_RAM__
+	static
+#endif
+	const struct fmap *fmap = NULL;
+	const struct fmap_area *area;
+	void *base = NULL;
+
+	if (!fmap)
+		fmap = fmap_find();
+
+	area = find_fmap_area(fmap, name);
+
+	if (!area)
+		return -1;
+
+	/* Right now cros_bundle_firmware does not write a valid
+	 * base address into the FMAP. Hence, if base is 0, assume
+	 * 4GB-8MB as base address.
+	 */
+	if (fmap->base) {
+		base = (void *)(unsigned long)fmap->base;
+	} else {
+		printk(BIOS_WARNING, "FMAP: No valid base address, using"
+				" 0x%08x\n", CONFIG_MRC_CACHE_BASE);
+		base = (void *)CONFIG_MRC_CACHE_BASE;
+	}
+
+	*pointer = base + area->offset;
+
+	return area->size;
+}