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/include/assets.h

@@ -0,0 +1,91 @@
+/*
+ * 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.
+ */
+#ifndef ASSETS_H
+#define ASSETS_H
+
+#include <region.h>
+
+/* An asset represents data used to boot the system. It can be found within
+ * CBFS or some other mechanism. While CBFS can be a source of an asset, note
+ * that using the asset API implies querying of other sources. */
+
+enum asset_type {
+	ASSET_UNKNOWN,
+	ASSET_VERSTAGE,
+	ASSET_ROMSTAGE,
+	ASSET_RAMSTAGE,
+	ASSET_REFCODE,
+	ASSET_PAYLOAD,
+	ASSET_BL31,
+};
+
+struct asset {
+	enum asset_type type;
+	const char *name;
+	struct region_device rdev;
+};
+
+static inline const char *asset_name(const struct asset *asset)
+{
+	return asset->name;
+}
+
+static inline enum asset_type asset_type(const struct asset *asset)
+{
+	return asset->type;
+}
+
+static struct region_device *asset_rdev(struct asset *asset)
+{
+	return &asset->rdev;
+}
+
+static inline size_t asset_size(const struct asset *asset)
+{
+	return region_device_sz(&asset->rdev);
+}
+
+/* Returns NULL on error. */
+static inline void *asset_mmap(const struct asset *asset)
+{
+	return rdev_mmap_full(&asset->rdev);
+}
+
+#define ASSET_INIT(type_, name_)	\
+	{				\
+		.type = (type_),	\
+		.name = (name_),	\
+	}
+
+/* Locate the asset as described by the parameter. It will query all known
+ * asset providers. Returns 0 on success. < 0 on error. */
+int asset_locate(struct asset *asset);
+
+struct asset_provider {
+	const char *name;
+	/* Determines if the provider is the active one. If so returns 1 else 0
+	 * or < 0 on error. */
+	int (*is_active)(struct asset *asset);
+	/* Returns < 0 on error or 0 on success. This function locates
+	 * the rdev representing the file data associated with the passed in
+	 * prog. */
+	int (*locate)(struct asset *asset);
+};
+
+#endif /* ASSETS_H */