vboot2: Implement new vb2ex_hwcrypto API

This patch aligns our verstage code to the new API addition in vboot2.
The hardware crypto functions are stubbed out by default and just
pretend that all algorithms are unsupported, causing vboot to fall back
to the normal software hashing code. These weak symbols can be
overridden by individual platform code to provide actual hardware
crypto engine support.

CQ-DEPEND=CL:236453
BRANCH=None
BUG=chrome-os-partner:32987
TEST=Booted Pinky, confirmed vboot falls back to software crypto.

Original-Change-Id: Idf6a38febd163aa2bff6e9a0e207213f01ca8324
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/236435
Original-Reviewed-by: Randall Spangler <rspangler@chromium.org>

(cherry picked from commit 9b5ee7f575f1aa3b0eb6ef78947ca93a4818f57b)
Signed-off-by: Aaron Durbin <adurbin@chromium.org>

Change-Id: I6f0e19255a9bc5c5cd1767db76f1e47897ef0798
Reviewed-on: http://review.coreboot.org/9703
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/vendorcode/google/chromeos/vboot2/verstage.c b/src/vendorcode/google/chromeos/vboot2/verstage.c
index 569e6e569c..06d76fe24a 100644
--- a/src/vendorcode/google/chromeos/vboot2/verstage.c
+++ b/src/vendorcode/google/chromeos/vboot2/verstage.c
@@ -19,6 +19,7 @@
 
 #include <antirollback.h>
 #include <arch/exception.h>
+#include <assert.h>
 #include <console/console.h>
 #include <console/vtxprintf.h>
 #include <delay.h>
@@ -91,6 +92,28 @@ int vb2ex_read_resource(struct vb2_context *ctx,
 	return VB2_SUCCESS;
 }
 
+/* No-op stubs that can be overridden by SoCs with hardware crypto support. */
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_init(enum vb2_hash_algorithm hash_alg,
+			       uint32_t data_size)
+{
+	return VB2_ERROR_EX_HWCRYPTO_UNSUPPORTED;
+}
+
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_extend(const uint8_t *buf, uint32_t size)
+{
+	BUG();	/* Should never get called if init() returned an error. */
+	return VB2_ERROR_UNKNOWN;
+}
+
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_finalize(uint8_t *digest, uint32_t digest_size)
+{
+	BUG();	/* Should never get called if init() returned an error. */
+	return VB2_ERROR_UNKNOWN;
+}
+
 static int hash_body(struct vb2_context *ctx, struct vboot_region *fw_main)
 {
 	uint64_t load_ts;