assets: abstract away the firmware assets used for booting

As there can be more than one source of firmware assets this
patch generalizes the notion of locating a particular asset.
struct asset is added along with some helper functions for
working on assets as a first class citizen.

Change-Id: I2ce575d1e5259aed4c34c3dcfd438abe9db1d7b9
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/10264
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins)

src/lib/assets.c

@@ -0,0 +1,93 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * 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.
+ */
+
+
+#include <assets.h>
+#include <boot_device.h>
+#include <cbfs.h>
+#include <console/console.h>
+#include <rules.h>
+#include <stdlib.h>
+
+#define DEFAULT_CBFS_PROVIDER_PRESENT \
+	(!ENV_VERSTAGE || (ENV_VERSTAGE && !CONFIG_RETURN_FROM_VERSTAGE))
+
+#if DEFAULT_CBFS_PROVIDER_PRESENT
+static int cbfs_boot_asset_locate(struct asset *asset)
+{
+	return cbfs_boot_locate(&asset->rdev, asset->name, NULL);
+}
+
+static const struct asset_provider cbfs_default_provider = {
+	.name = "CBFS",
+	.locate = cbfs_boot_asset_locate,
+};
+#endif
+
+extern const struct asset_provider vboot_provider;
+
+static const struct asset_provider *providers[] = {
+#if CONFIG_VBOOT_VERIFY_FIRMWARE
+	&vboot_provider,
+#endif
+#if DEFAULT_CBFS_PROVIDER_PRESENT
+	&cbfs_default_provider,
+#endif
+};
+
+int asset_locate(struct asset *asset)
+{
+	int i;
+
+	boot_device_init();
+
+	for (i = 0; i < ARRAY_SIZE(providers); i++) {
+		/* Default provider state is active. */
+		int ret = 1;
+		const struct asset_provider *ops;
+
+		ops = providers[i];
+
+		if (ops->is_active != NULL)
+			ret = ops->is_active(asset);
+
+		if (ret == 0) {
+			printk(BIOS_DEBUG, "%s provider inactive.\n",
+				ops->name);
+			continue;
+		} else if (ret < 0) {
+			printk(BIOS_DEBUG, "%s provider failure.\n",
+				ops->name);
+			continue;
+		}
+
+		printk(BIOS_DEBUG, "%s provider active.\n", ops->name);
+
+		if (ops->locate(asset))
+			continue;
+
+		printk(BIOS_DEBUG, "'%s' located at offset: %zx size: %zx\n",
+			asset->name, region_device_offset(&asset->rdev),
+			region_device_sz(&asset->rdev));
+
+		return 0;
+	}
+
+	return -1;
+}