cbfs: Move more stuff into cbfs_boot_lookup()

cbfs_boot_locate() is supposed to be deprecated eventually, after slowly
migrating all APIs to bypass it. That means common features (like
RO-fallback or measurement) need to be moved to the new
cbfs_boot_lookup().

Also export the function externally. Since it is a low-level API and
most code should use the higher-level loading or mapping functions
instead, put it into a new <cbfs_private.h> to raise the mental barrier
for using this API (this will make more sense once cbfs_boot_locate() is
removed from <cbfs.h>).

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I4bc9b7cbc42a4211d806a3e3389abab7f589a25a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39327
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/include/cbfs_private.h b/src/include/cbfs_private.h
new file mode 100644
index 0000000000..8e9803616f
--- /dev/null
+++ b/src/include/cbfs_private.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _CBFS_PRIVATE_H_
+#define _CBFS_PRIVATE_H_
+
+#include <commonlib/bsd/cbfs_private.h>
+#include <commonlib/region.h>
+#include <types.h>
+
+/*
+ * This header contains low-level CBFS APIs that should only be used by code
+ * that really needs this level of access. Most code (particularly platform
+ * code) should use the higher-level CBFS APIs in <cbfs.h>. Code using these
+ * APIs needs to take special care to ensure CBFS file data is verified (in a
+ * TOCTOU-safe manner) before access (TODO: add details on how to do this once
+ * file verification code is in).
+ */
+
+/* Find by name, load metadata into |mdata| and chain file data to |rdev|. */
+cb_err_t cbfs_boot_lookup(const char *name, bool force_ro,
+			  union cbfs_mdata *mdata, struct region_device *rdev);
+
+#endif