[PATCH 12/34] cbfs: Allow access to CBFS without a header

[Simon Glass]

In some cases CBFS does not start with a header but is just a collection
of files. It is possible to support this so long as the size of the CBFS
is provided.

Update the cbfs_init_mem() function to support this.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/x86/lib/fsp2/fsp_init.c |  3 ++-
 fs/cbfs/cbfs.c               | 18 +++++++++++++-----
 include/cbfs.h               |  8 ++++++--
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/arch/x86/lib/fsp2/fsp_init.c b/arch/x86/lib/fsp2/fsp_init.c
index 85cae54a0ca..5afdce1e0d4 100644
--- a/arch/x86/lib/fsp2/fsp_init.c
+++ b/arch/x86/lib/fsp2/fsp_init.c
@@ -84,7 +84,8 @@ static int get_cbfs_fsp(enum fsp_type_t type, ulong map_base,
 	struct cbfs_priv *cbfs;
 	int ret;
 
-	ret = cbfs_init_mem(map_base + cbfs_base, &cbfs);
+	ret = cbfs_init_mem(map_base + cbfs_base, CBFS_SIZE_UNKNOWN, true,
+			    &cbfs);
 	if (ret)
 		return ret;
 	if (!ret) {
diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c
index c9323a562c6..13a74e6ed43 100644
--- a/fs/cbfs/cbfs.c
+++ b/fs/cbfs/cbfs.c
@@ -276,18 +276,26 @@ int file_cbfs_init(ulong end_of_rom)
 	return cbfs_init(&cbfs_s, end_of_rom);
 }
 
-int cbfs_init_mem(ulong base, struct cbfs_priv **privp)
+int cbfs_init_mem(ulong base, ulong size, bool require_hdr,
+		  struct cbfs_priv **privp)
 {
 	struct cbfs_priv priv_s, *priv = &priv_s;
 	int ret;
 
 	/*
-	 * Use a local variable to start with until we know that the CBFS is
-	 * valid.
+	 * Use a local variable to start with until we know that the * CBFS is
+	 * valid. Note that size is detected from the header, if present,
+	 * meaning the parameter is ignored.
 	 */
 	ret = cbfs_load_header_ptr(priv, base);
-	if (ret)
-		return ret;
+	if (ret) {
+		if (require_hdr || size == CBFS_SIZE_UNKNOWN)
+			return ret;
+		memset(priv, '\0', sizeof(struct cbfs_priv));
+		priv->header.rom_size = size;
+		priv->header.align = CBFS_ALIGN_SIZE;
+		priv->start = (void *)base;
+	}
 
 	ret = file_cbfs_fill_cache(priv, priv->header.rom_size,
 				   priv->header.align);
diff --git a/include/cbfs.h b/include/cbfs.h
index d98afea6480..05770e2c7ec 100644
--- a/include/cbfs.h
+++ b/include/cbfs.h
@@ -42,6 +42,8 @@ enum cbfs_filetype {
 
 enum {
 	CBFS_HEADER_MAGIC	= 0x4f524243,
+	CBFS_SIZE_UNKNOWN	= 0xffffffff,
+	CBFS_ALIGN_SIZE		= 0x40,
 };
 
 /**
@@ -186,11 +188,13 @@ const struct cbfs_cachenode *cbfs_find_file(struct cbfs_priv *cbfs,
  * cbfs_init_mem() - Set up a new CBFS
  *
  * @base: Base address of CBFS
+ * @size: Size of CBFS if known, else CBFS_SIZE_UNKNOWN
+ * @require_header: true to read a header at the start, false to not require one
  * @cbfsp: Returns a pointer to CBFS on success
  * @return 0 if OK, -ve on error
  */
-int cbfs_init_mem(ulong base, struct cbfs_priv **privp);
-
+int cbfs_init_mem(ulong base, ulong size, bool require_hdr,
+		  struct cbfs_priv **privp);
 
 /***************************************************************************/
 /* All of the functions below can be used without first initializing CBFS. */
-- 
2.31.0.rc2.261.g7f71774620-goog