cbfs: Add functions to support multiple CBFSs

Sometimes an image has multiple CBFS. The current CBFS API is limited to
handling only one at time. Also it keeps track of the CBFS internally in
BSS, which does not work before relocation, for example.

Add a few new functions to overcome these limitations.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c
index d9a8562..35f919a 100644
--- a/fs/cbfs/cbfs.c
+++ b/fs/cbfs/cbfs.c
@@ -187,6 +187,23 @@
 	return 0;
 }
 
+static int cbfs_load_header_ptr(struct cbfs_priv *priv, ulong base,
+				struct cbfs_header *header)
+{
+	struct cbfs_header *header_in_rom;
+
+	header_in_rom = (struct cbfs_header *)base;
+	swap_header(header, header_in_rom);
+
+	if (header->magic != good_magic || header->offset >
+			header->rom_size - header->boot_block_size) {
+		priv->result = CBFS_BAD_HEADER;
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
 static void cbfs_init(struct cbfs_priv *priv, uintptr_t end_of_rom)
 {
 	u8 *start_of_rom;
@@ -209,6 +226,35 @@
 	cbfs_init(&cbfs_s, end_of_rom);
 }
 
+int cbfs_init_mem(ulong base, ulong size, 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. Assume that a master header appears at the start, at offset
+	 * 0x38.
+	 */
+	ret = cbfs_load_header_ptr(priv, base + 0x38, &priv->header);
+	if (ret)
+		return ret;
+
+	file_cbfs_fill_cache(priv, (u8 *)base, priv->header.rom_size,
+			     priv->header.align);
+	if (priv->result != CBFS_SUCCESS)
+		return -EINVAL;
+
+	priv->initialized = 1;
+	priv = malloc(sizeof(priv_s));
+	if (!priv)
+		return -ENOMEM;
+	memcpy(priv, &priv_s, sizeof(priv_s));
+	*privp = priv;
+
+	return 0;
+}
+
 const struct cbfs_header *file_cbfs_get_header(void)
 {
 	struct cbfs_priv *priv = &cbfs_s;