Add code to read Intel microcode from CBFS

When CONFIG_MICROCODE_IN_CBFS is enabled, find the microcode blob in
CBFS and pass it to intel_update_microcode() instead of using the
compiled in array.

CBFS accesses in pre-RAM and 'normal' environments are provided
through different API.

Change-Id: I35c1480edf87e550a7b88c4aadf079cf3ff86b5d
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: http://review.coreboot.org/1296
Tested-by: build bot (Jenkins)

src/cpu/intel/microcode/microcode.c

@@ -1,6 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
  * Copyright (C) 2000 Ronald G. Minnich
  *
  * This program is free software; you can redistribute it and/or modify
@@ -27,6 +28,14 @@
 #include <cpu/x86/msr.h>
 #include <cpu/intel/microcode.h>
 
+#if CONFIG_MICROCODE_IN_CBFS
+#ifdef __PRE_RAM__
+#include <arch/cbfs.h>
+#else
+#include <cbfs.h>
+#endif
+#endif
+
 struct microcode {
 	u32 hdrver;	/* Header Version */
 	u32 rev;	/* Update Revision */
@@ -68,6 +77,9 @@ static inline u32 read_microcode_rev(void)
 	return msr.hi;
 }
 
+#if CONFIG_MICROCODE_IN_CBFS
+static
+#endif
 void intel_update_microcode(const void *microcode_updates)
 {
 	u32 eax;
@@ -131,3 +143,21 @@ void intel_update_microcode(const void *microcode_updates)
 		}
 	}
 }
+
+#if CONFIG_MICROCODE_IN_CBFS
+
+#define MICROCODE_CBFS_FILE "microcode_blob.bin"
+
+void intel_update_microcode_from_cbfs(void)
+{
+	void *microcode_blob;
+
+#ifdef __PRE_RAM__
+	microcode_blob = walkcbfs((char *) MICROCODE_CBFS_FILE);
+#else
+	microcode_blob = cbfs_find_file(MICROCODE_CBFS_FILE,
+					CBFS_TYPE_MICROCODE);
+#endif
+	intel_update_microcode(microcode_blob);
+}
+#endif