Implementation of Region APIstabilize-4636.B

At present reading data from storage in Vboot is a little fragmented. For
the firmware image, we expect the boot loader to handle this. For the disk
we have a block-level API. For the GBB (which also sits in the firmware
image) we expect the entire thing to be read before Vboot is called.

Add the concept of a region, and an API to read from a region. At present,
and most pressing, is reading from a GBB region. In the future this could
be extended to other parts of the firmware or even the disk.

Move all access to the GBB into this API so that the boot loader can provide
either a GBB region in one large contiguous chunk, or a function to deal with
read requests from vboot.

The call to VbExRegionRead() is behind a flag since not all boot loaders
support it yet.

The main change for boot loaders which don't support this new API is that
vboot will do more behind the scenes. For example, it will allocate memory
for chunks of data that it reads from the GBB, rather than just accessing it
directly. This approach is considerably simpler than trying to pass char **
everywhere and have vboot decide whether something needs to be allocated or
not.

The tests are updated, mainly to include setting up a GBB structure
accessible from VbCommonParams, which is now required by the firmware and
kernel functions. In normal operation this is set up at the start of
VbLoadFIrmware() and VbSelectAndLoadKernel() but for tests which call
children of these functions directly, the GBB structure must be set up
manually by the test.

BUG=chrome-os-partner:21115
BRANCH=none
TEST=manual
FEATURES=test sudo -E  emerge vboot_reference

Change-Id: If2b8bbe467fdbd643239d8d9b5d7aa98df4d286f
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/63336
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/167361

3 files changed, 179 insertions, 0 deletions

diff --git a/firmware/include/gbb_access.h b/firmware/include/gbb_access.h
new file mode 100644
index 00000000..b94d0cdb
--- /dev/null
+++ b/firmware/include/gbb_access.h
@@ -0,0 +1,83 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Access to portions of the GBB using the region API.
+ */
+
+#ifndef VBOOT_REFERENCE_GBB_ACCESS_H_
+#define VBOOT_REFERENCE_GBB_ACCESS_H_
+
+#include "vboot_api.h"
+
+struct BmpBlockHeader;
+struct ImageInfo;
+struct GoogleBinaryBlockHeader;
+struct ScreenLayout;
+struct VbPublicKey;
+
+/**
+ * Read the GBB header
+ *
+ * This accesses the GBB and reads its header.
+ *
+ * @param cparams	Vboot common parameters
+ * @param gbb		Place to put GBB header
+ */
+VbError_t VbGbbReadHeader_static(VbCommonParams *cparams,
+				 struct GoogleBinaryBlockHeader *gbb);
+
+/**
+ * Read the root key from the GBB
+ *
+ * @param cparams	Vboot common parameters
+ * @param keyp		Returns a pointer to the key. The caller must call
+ *			VbExFree() on the key when finished with it.
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbGbbReadRootKey(VbCommonParams *cparams,
+			   struct VbPublicKey **keyp);
+
+/**
+ * Read the recovery key from the GBB
+ *
+ * @param cparams	Vboot common parameters
+ * @param keyp		Returns a pointer to the key. The caller must call
+ *			VbExFree() on the key when finished with it.
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbGbbReadRecoveryKey(VbCommonParams *cparams,
+			       struct VbPublicKey **keyp);
+
+/**
+ * Read the bitmap block header from the GBB
+ *
+ * @param cparams	Vboot common parameters
+ * @param hdr		The header is placed in this block
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbGbbReadBmpHeader(VbCommonParams *cparams,
+			     struct BmpBlockHeader *hdr);
+
+/**
+ * Read a image from the GBB
+ *
+ * The caller must call VbExFree() on *image_datap when finished with it.
+ *
+ * @param cparams	Vboot common parameters
+ * @param localization	Localization/language number
+ * @param screen_index	Index of screen to display (VB_SCREEN_...)
+ * @param image_num	Image number within the screen
+ * @param layout	Returns layout information (x, y position)
+ * @param image_info	Returns information about the image (format)
+ * @param image_datap	Returns a pointer to the image data
+ * @param iamge_data_sizep	Return size of image data
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbGbbReadImage(VbCommonParams *cparams,
+			 uint32_t localization, uint32_t screen_index,
+			 uint32_t image_num, struct ScreenLayout *layout,
+			 struct ImageInfo *image_info, char **image_datap,
+			 uint32_t *image_data_sizep);
+
+#endif
diff --git a/firmware/include/region.h b/firmware/include/region.h
new file mode 100644
index 00000000..78e1dba0
--- /dev/null
+++ b/firmware/include/region.h
@@ -0,0 +1,55 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Access to portions of the firmware image, perhaps later to be expanded
+ * to other devices.
+ */
+
+#ifndef VBOOT_REFERENCE_REGION_H_
+#define VBOOT_REFERENCE_REGION_H_
+
+#include "bmpblk_header.h"
+#include "gbb_header.h"
+#include "vboot_api.h"
+#include "vboot_struct.h"
+
+/* The maximum length of a hardware ID */
+#define VB_REGION_HWID_LEN	256
+
+/**
+ * Read data from a region
+ *
+ * @param cparams	Vboot common parameters
+ * @param region	Region number to read
+ * @param offset	Offset within region to start reading
+ * @param size		Size of data to read
+ * @param buf		Buffer to put the data into
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbRegionReadData(VbCommonParams *cparams,
+			   enum vb_firmware_region region, uint32_t offset,
+			   uint32_t size, void *buf);
+
+/**
+ * Check the version of the GBB and print debug information if valid
+ *
+ * @param cparams	Vboot common parameters
+ */
+void VbRegionCheckVersion(VbCommonParams *cparams);
+
+/**
+ * Read the hardware ID from the GBB
+ *
+ * @param cparams	Vboot common parameters
+ * @param hwid		Place to put HWID, which will be null-terminated
+ * @param max_size	Maximum size of HWID including terminated null
+ *			character (suggest VB_REGION_HWID_LEN). If this size
+ *			it too small then VBERROR_INVALID_PARAMETER is
+ *			returned.
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbRegionReadHWID(VbCommonParams *cparams, char *hwid,
+			   uint32_t max_size);
+
+#endif  /* VBOOT_REFERENCE_REGION_H_ */
diff --git a/firmware/include/vboot_api.h b/firmware/include/vboot_api.h
index 10adc377..214da753 100644
--- a/firmware/include/vboot_api.h
+++ b/firmware/include/vboot_api.h
@@ -104,6 +104,14 @@ enum VbErrorPredefined_t {
 	VBERROR_VGA_OPROM_MISMATCH            = 0x10021,
 	/* Need EC to reboot to read-only code */
 	VBERROR_EC_REBOOT_TO_RO_REQUIRED      = 0x10022,
+	/* Invalid region read parameters */
+	VBERROR_REGION_READ_INVALID           = 0x10023,
+	/* Cannot read from region */
+	VBERROR_REGION_READ_FAILED            = 0x10024,
+	/* Unsupported region type */
+	VBERROR_UNSUPPORTED_REGION            = 0x10025,
+	/* No image present (returned from VbGbbReadImage() for missing image) */
+	VBERROR_NO_IMAGE_PRESENT              = 0x10026,
 
 	/* VbExEcGetExpectedRWHash() may return the following codes */
 	/* Compute expected RW hash from the EC image; BIOS doesn't have it */
@@ -167,6 +175,10 @@ typedef struct VbCommonParams {
 	 * the stack.
 	 */
 	void *caller_context;
+
+	/* For internal use of Vboot - do not examine or modify! */
+	struct GoogleBinaryBlockHeader *gbb;
+	struct BmpBlockHeader *bmp;
 } VbCommonParams;
 
 /* Flags for VbInitParams.flags */
@@ -827,4 +839,33 @@ enum {
  */
 int VbExLegacy(void);
 
+/* Regions for VbExRegionRead() */
+enum vb_firmware_region {
+	VB_REGION_GBB,	/* Google Binary Block - see gbbheader.h */
+
+	VB_REGION_COUNT,
+};
+
+/**
+ * Read data from a region of the firmware image
+ *
+ * Vboot wants access to a region, to read data from it. This function
+ * reads it (typically from the firmware image such as SPI flash) and
+ * returns the data.
+ *
+ * cparams is passed so that the boot loader has some context for the
+ * operation.
+ *
+ * @param cparams	Common parameters, e.g. use member caller_context
+ *			to point to useful context data
+ * @param region	Firmware region to read
+ * @param offset	Start offset within region
+ * @param size		Number of bytes to read
+ * @param buf		Place to put data
+ * @return VBERROR_... error, VBERROR_SUCCESS on success,
+ */
+VbError_t VbExRegionRead(VbCommonParams *cparams,
+			 enum vb_firmware_region region, uint32_t offset,
+			 uint32_t size, void *buf);
+
 #endif  /* VBOOT_REFERENCE_VBOOT_API_H_ */