cbfs: Make cbfs_master_header_props() externally available

This patch makes the CBFS default locator .locate() callback externally
available so that code which overrides cbfs_master_header_locator can
reuse or wrap it and doesn't have to copy&paste the whole thing. Use it
for the Eltan vendorcode implementation which previously did this.

Change-Id: I54dad5c8ea64ea0fc472217e275daa815736991e
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36797
Reviewed-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 5 insertions, 43 deletions

diff --git a/src/include/cbfs.h b/src/include/cbfs.h
index 85e25b3d9b..f012441896 100644
--- a/src/include/cbfs.h
+++ b/src/include/cbfs.h
@@ -73,6 +73,9 @@ struct cbfs_props {
 	size_t size;
 };
 
+/* Default CBFS locator .locate() callback that locates "COREBOOT" region. */
+int cbfs_master_header_props(struct cbfs_props *props);
+
 /* Return < 0 on error otherwise props are filled out accordingly. */
 int cbfs_boot_region_properties(struct cbfs_props *props);
 
diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c
index 13b5afb6ea..1601f201fe 100644
--- a/src/lib/cbfs.c
+++ b/src/lib/cbfs.c
@@ -298,7 +298,7 @@ out:
 }
 
 /* This only supports the "COREBOOT" fmap region. */
-static int cbfs_master_header_props(struct cbfs_props *props)
+int cbfs_master_header_props(struct cbfs_props *props)
 {
 	struct cbfs_header header;
 	const struct region_device *bdev;
diff --git a/src/vendorcode/eltan/security/verified_boot/vboot_check.c b/src/vendorcode/eltan/security/verified_boot/vboot_check.c
index 1dc1c3a37f..823c2de412 100644
--- a/src/vendorcode/eltan/security/verified_boot/vboot_check.c
+++ b/src/vendorcode/eltan/security/verified_boot/vboot_check.c
@@ -17,7 +17,6 @@
 #include <cbfs.h>
 #include <vboot_check.h>
 #include <vboot_common.h>
-#include "fmap_config.h"
 
 #define RSA_PUBLICKEY_FILE_NAME "vboot_public_key.bin"
 
@@ -91,46 +90,6 @@ fail:
 	return -1;
 }
 
-static int vendor_secure_locate(struct cbfs_props *props)
-{
-	struct cbfs_header header;
-	const struct region_device *bdev;
-	int32_t rel_offset;
-	size_t offset;
-
-	bdev = boot_device_ro();
-
-	if (bdev == NULL)
-		return -1;
-
-	size_t fmap_top = ___FMAP__COREBOOT_BASE + ___FMAP__COREBOOT_SIZE;
-
-	/* Find location of header using signed 32-bit offset from
-	 * end of CBFS region. */
-	offset = fmap_top - sizeof(int32_t);
-	if (rdev_readat(bdev, &rel_offset, offset, sizeof(int32_t)) < 0)
-		return -1;
-
-	offset = fmap_top + rel_offset;
-	if (rdev_readat(bdev, &header, offset, sizeof(header)) < 0)
-		return -1;
-
-	header.magic = ntohl(header.magic);
-	header.romsize = ntohl(header.romsize);
-	header.offset = ntohl(header.offset);
-
-	if (header.magic != CBFS_HEADER_MAGIC)
-		return -1;
-
-	props->offset = header.offset;
-	props->size = header.romsize;
-	props->size -= props->offset;
-
-	printk(BIOS_SPEW, "CBFS @ %zx size %zx\n", props->offset, props->size);
-
-	return 0;
-}
-
 /*
  *
  * measure_item
@@ -399,5 +358,5 @@ static void vendor_secure_prepare(void)
 const struct cbfs_locator cbfs_master_header_locator = {
 	.name = "Vendorcode Header Locator",
 	.prepare = vendor_secure_prepare,
-	.locate = vendor_secure_locate
+	.locate = cbfs_master_header_props
 };