vboot2: Add workbuf functions

We'll try breaking this up into smaller pieces.  This one's pretty
small - just the work buffer utility functions.

BUG=chromium:370082
BRANCH=none
TEST=make clean && VBOOT2=1 COV=1 make

Change-Id: I4c417438053c155d6f7f9725552066e9b059951c
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/201141

4 files changed, 304 insertions, 0 deletions

diff --git a/firmware/2lib/2common.c b/firmware/2lib/2common.c
new file mode 100644
index 00000000..9849b22b
--- /dev/null
+++ b/firmware/2lib/2common.c
@@ -0,0 +1,95 @@
+/* Copyright (c) 2014 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.
+ *
+ * Common functions between firmware and kernel verified boot.
+ * (Firmware portion)
+ */
+
+#include "2sysincludes.h"
+#include "2common.h"
+
+int vb2_align(uint8_t **ptr, uint32_t *size, uint32_t align, uint32_t want_size)
+{
+	uintptr_t p = (uintptr_t)*ptr;
+	uintptr_t offs = p & (align - 1);
+
+	if (offs) {
+		offs = align - offs;
+
+		if (*size < offs)
+			return VB2_ERROR_BUFFER_TOO_SMALL;
+
+		*ptr += offs;
+		*size -= offs;
+	}
+
+	if (*size < want_size)
+		return VB2_ERROR_BUFFER_TOO_SMALL;
+
+	return VB2_SUCCESS;
+}
+
+void vb2_workbuf_init(struct vb2_workbuf *wb, uint8_t *buf, uint32_t size)
+{
+	wb->buf = buf;
+	wb->size = size;
+
+	/* Align the buffer so allocations will be aligned */
+	if (vb2_align(&wb->buf, &wb->size, VB2_WORKBUF_ALIGN, 0))
+		wb->size = 0;
+}
+
+/**
+ * Round up a number to a multiple of VB2_WORKBUF_ALIGN
+ *
+ * @param v		Number to round up
+ * @return The number, rounded up.
+ */
+static __inline uint32_t wb_round_up(uint32_t v)
+{
+	return (v + VB2_WORKBUF_ALIGN - 1) & ~(VB2_WORKBUF_ALIGN - 1);
+}
+
+void *vb2_workbuf_alloc(struct vb2_workbuf *wb, uint32_t size)
+{
+	uint8_t *ptr = wb->buf;
+
+	/* Round up size to work buffer alignment */
+	size = wb_round_up(size);
+
+	if (size > wb->size)
+		return NULL;
+
+	wb->buf += size;
+	wb->size -= size;
+
+	return ptr;
+}
+
+void *vb2_workbuf_realloc(struct vb2_workbuf *wb,
+			  uint32_t oldsize,
+			  uint32_t newsize)
+{
+	/*
+	 * Just free and allocate to update the size.  No need to move/copy
+	 * memory, since the new pointer is guaranteed to be the same as the
+	 * old one.  The new allocation can fail, if the new size is too big.
+	 */
+	vb2_workbuf_free(wb, oldsize);
+	return vb2_workbuf_alloc(wb, newsize);
+}
+
+void vb2_workbuf_free(struct vb2_workbuf *wb, uint32_t size)
+{
+	/* Round up size to work buffer alignment */
+	size = wb_round_up(size);
+
+	wb->buf -= size;
+	wb->size += size;
+}
+
+ptrdiff_t vb2_offset_of(const void *base, const void *ptr)
+{
+	return (uintptr_t)ptr - (uintptr_t)base;
+}
diff --git a/firmware/2lib/include/2common.h b/firmware/2lib/include/2common.h
new file mode 100644
index 00000000..3724354b
--- /dev/null
+++ b/firmware/2lib/include/2common.h
@@ -0,0 +1,120 @@
+/* Copyright (c) 2014 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.
+ *
+ * Common functions between firmware and kernel verified boot.
+ */
+
+#ifndef VBOOT_REFERENCE_VBOOT_2COMMON_H_
+#define VBOOT_REFERENCE_VBOOT_2COMMON_H_
+
+#include "2return_codes.h"
+
+struct vb2_public_key;
+
+/*
+ * Return the greater of A and B.  This is used in macros which calculate the
+ * required buffer size, so can't be turned into a static inline function.
+ */
+#ifndef VB2_MAX
+#define VB2_MAX(A, B) ((A) > (B) ? (A) : (B))
+#endif
+
+/*
+ * Debug output.  Defaults to printf(), but can be overridden on a per-platform
+ * basis.
+ */
+#if defined(VBOOT_DEBUG) && !defined(VB2_DEBUG)
+#define VB2_DEBUG(format, args...) printf(format, ## args)
+#else
+#define VB2_DEBUG(format, args...)
+#endif
+
+/* Alignment for work buffer pointers/allocations */
+#define VB2_WORKBUF_ALIGN 8
+
+/* Work buffer */
+struct vb2_workbuf {
+	uint8_t *buf;
+	uint32_t size;
+};
+
+/**
+ * Initialize a work buffer.
+ *
+ * @param wb		Work buffer to init
+ * @param buf		Pointer to work buffer data
+ * @param size		Size of work buffer data in bytes
+ */
+void vb2_workbuf_init(struct vb2_workbuf *wb, uint8_t *buf, uint32_t size);
+
+/**
+ * Allocate space in a work buffer.
+ *
+ * Note that the returned buffer will always be aligned to VB2_WORKBUF_ALIGN.
+ *
+ * The work buffer acts like a stack, and detailed tracking of allocs and frees
+ * is not done.  The caller must track the size of each allocation and free via
+ * vb2_workbuf_free() in the reverse order they were allocated.
+ *
+ * @param wb		Work buffer
+ * @param size		Requested size in bytes
+ * @return A pointer to the allocated space, or NULL if error.
+ */
+void *vb2_workbuf_alloc(struct vb2_workbuf *wb, uint32_t size);
+
+/**
+ * Reallocate space in a work buffer.
+ *
+ * Note that the returned buffer will always be aligned to VB2_WORKBUF_ALIGN.
+ * The work buffer acts like a stack, so this must only be done to the most
+ * recently allocated buffer.
+ *
+ * @param wb		Work buffer
+ * @param oldsize	Old allocation size in bytes
+ * @param newsize	Requested size in bytes
+ * @return A pointer to the allocated space, or NULL if error.
+ */
+void *vb2_workbuf_realloc(struct vb2_workbuf *wb,
+			  uint32_t oldsize,
+			  uint32_t newsize);
+
+/**
+ * Free the preceding allocation.
+ *
+ * Note that the work buffer acts like a stack, and detailed tracking of
+ * allocs and frees is not done.  The caller must track the size of each
+ * allocation and free them in reverse order.
+ *
+ * @param wb		Work buffer
+ * @param size		Size of data to free
+ */
+void vb2_workbuf_free(struct vb2_workbuf *wb, uint32_t size);
+
+/* Check if a pointer is aligned on an align-byte boundary */
+#define vb_aligned(ptr, align) (!(((size_t)(ptr)) & ((align) - 1)))
+
+/**
+ * Align a buffer and check its size.
+ *
+ * @param **ptr		Pointer to pointer to align
+ * @param *size		Points to size of buffer pointed to by *ptr
+ * @param align		Required alignment (must be power of 2)
+ * @param want_size	Required size
+ * @return VB2_SUCCESS, or non-zero if error.
+ */
+int vb2_align(uint8_t **ptr,
+	      uint32_t *size,
+	      uint32_t align,
+	      uint32_t want_size);
+
+/**
+ * Return offset of ptr from base.
+ *
+ * @param base		Base pointer
+ * @param ptr		Pointer at some offset from base
+ * @return The offset of ptr from base.
+ */
+ptrdiff_t vb2_offset_of(const void *base, const void *ptr);
+
+#endif  /* VBOOT_REFERENCE_VBOOT_2COMMON_H_ */
diff --git a/firmware/2lib/include/2return_codes.h b/firmware/2lib/include/2return_codes.h
new file mode 100644
index 00000000..73a37b5e
--- /dev/null
+++ b/firmware/2lib/include/2return_codes.h
@@ -0,0 +1,62 @@
+/* Copyright (c) 2014 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.
+ */
+
+#ifndef VBOOT_2_RETURN_CODES_H_
+#define VBOOT_2_RETURN_CODES_H_
+
+/*
+ * Return codes from verified boot functions.
+ *
+ * TODO: Go through code and replace VB2_ERROR_UNKNOWN with more specific
+ * error codes, and make the existing codes more consistent and useful.
+ */
+enum vb2_return_code {
+	/* Success - no error */
+	VB2_SUCCESS = 0,
+
+	/* Unknown / unspecified error */
+	VB2_ERROR_UNKNOWN = 0x10000,
+
+	/* Work buffer too small */
+	VB2_ERROR_WORKBUF_TOO_SMALL,
+
+	/* Buffer too small (other than the work buffer) */
+	VB2_ERROR_BUFFER_TOO_SMALL,
+
+	/* Buffer unaligned */
+	VB2_ERROR_BUFFER_UNALIGNED,
+
+	/* Bad GBB header */
+	VB2_ERROR_BAD_GBB_HEADER,
+
+	/* Bad algorithm - unknown, or unsupported */
+	VB2_ERROR_BAD_ALGORITHM,
+
+	/* Signature check failed */
+	VB2_ERROR_BAD_SIGNATURE,
+
+	/* Bad secure data */
+	VB2_ERROR_BAD_SECDATA,
+
+	/* Bad key */
+	VB2_ERROR_BAD_KEY,
+
+	/* Bad keyblock */
+	VB2_ERROR_BAD_KEYBLOCK,
+
+	/* Bad preamble */
+	VB2_ERROR_BAD_PREAMBLE,
+
+	/* Bad firmware keyblock version (out of range, or rollback) */
+	VB2_ERROR_FW_KEYBLOCK_VERSION,
+
+	/* Bad firmware version (out of range, or rollback) */
+	VB2_ERROR_FW_VERSION,
+
+	/* Bad hash tag */
+	VB2_ERROR_BAD_TAG,
+};
+
+#endif  /* VBOOT_2_RETURN_CODES_H_ */
diff --git a/firmware/2lib/include/2sysincludes.h b/firmware/2lib/include/2sysincludes.h
new file mode 100644
index 00000000..4c9e66c6
--- /dev/null
+++ b/firmware/2lib/include/2sysincludes.h
@@ -0,0 +1,27 @@
+/* Copyright (c) 2014 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.
+ */
+
+/*
+ * System includes for vboot reference library.  With few exceptions, this is
+ * the ONLY place in firmware/ where system headers may be included via
+ * #include <...>, so that there's only one place that needs to be fixed up for
+ * platforms which don't have all the system includes.
+ */
+
+#ifndef VBOOT_REFERENCE_2_SYSINCLUDES_H_
+#define VBOOT_REFERENCE_2_SYSINCLUDES_H_
+
+#include <inttypes.h>  /* For PRIu64 */
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(HAVE_ENDIAN_H) && defined(HAVE_LITTLE_ENDIAN)
+#include <byteswap.h>
+#include <memory.h>
+#endif
+
+#endif  /* VBOOT_REFERENCE_2_SYSINCLUDES_H_ */