1/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6/*
7 * Helper functions/wrappers for memory allocations, manipulation and
8 * comparison.
9 */
10
11#ifndef VBOOT_REFERENCE_UTILITY_H_
12#define VBOOT_REFERENCE_UTILITY_H_
13
14#include "sysincludes.h"
15#include "vboot_api.h"
16
17/* Debug and error output */
18#ifdef VBOOT_DEBUG
19#define VBDEBUG(params) VbExDebug params
20#else
21#define VBDEBUG(params)
22#endif
23
24#ifdef VBOOT_DEBUG
25#define VbAssert(expr) do { if (!(expr)) { \
26    VbExError("assert fail: %s at %s:%d\n", \
27              #expr, __FILE__, __LINE__); }} while(0)
28#else
29#define VbAssert(expr)
30#endif
31
32/* Optional, up to the BIOS */
33#ifdef VBOOT_EASTER_EGG
34#define VBEASTEREGG VbExEasterEgg()
35#else
36#define VBEASTEREGG 0
37#endif
38
39/*
40 * Combine [msw] and [lsw] uint16s to a uint32_t with its [msw] and [lsw]
41 * forming the most and least signficant 16-bit words.
42 */
43#define CombineUint16Pair(msw,lsw) (((uint32_t)(msw) << 16) |   \
44                                    (((lsw)) & 0xFFFF))
45
46/* Return the minimum of (a) or (b). */
47#define Min(a, b) (((a) < (b)) ? (a) : (b))
48
49/**
50 * Compare [n] bytes in [src1] and [src2].
51 *
52 * Returns an integer less than, equal to, or greater than zero if the first
53 * [n] bytes of [src1] is found, respectively, to be less than, to match, or be
54 * greater than the first n bytes of [src2]. */
55int Memcmp(const void *src1, const void *src2, size_t n);
56
57/**
58 * Copy [n] bytes from [src] to [dest].
59 */
60void *Memcpy(void *dest, const void *src, uint64_t n);
61
62/*
63 * Implementations of the functions below must be built as part of the firmware
64 * and defined in lib/utility.c.
65 */
66
67/**
68 * Set [n] bytes starting at [s] to [c].  Returns dest.
69 */
70void *Memset(void *dest, const uint8_t c, uint64_t n);
71
72/**
73 * Compare [n] bytes starting at [s1] with [s2] and return 0 if they
74 * match, 1 if they don't.  Returns 0 if n=0, since no bytes mismatched.
75 *
76 * Time taken to perform the comparison is only dependent on [n] and
77 * not on the relationship of the match between [s1] and [s2].
78 *
79 * Note that unlike Memcmp(), this only indicates inequality, not
80 * whether s1 is less than or greater than s2.
81 */
82int SafeMemcmp(const void *s1, const void *s2, size_t n);
83
84/*
85 * Buffer size required to hold the longest possible output of Uint64ToString()
86 * - that is, Uint64ToString(~0, 2).
87 */
88#define UINT64_TO_STRING_MAX 65
89
90/**
91 * Convert a value to a string in the specified radix (2=binary, 10=decimal,
92 * 16=hex) and store it in <buf>, which is <bufsize> chars long.  If
93 * <zero_pad_width>, left-pads the string to at least that width with '0'.
94 * Returns the length of the stored string, not counting the terminating null.
95 */
96uint32_t Uint64ToString(char *buf, uint32_t bufsize, uint64_t value,
97                        uint32_t radix, uint32_t zero_pad_width);
98
99/**
100 * Concatenate <src> onto <dest>, which has space for <destlen> characters
101 * including the terminating null.  Note that <dest> will always be
102 * null-terminated if <destlen> > 0.  Returns the number of characters used in
103 * <dest>, not counting the terminating null.
104 */
105uint32_t StrnAppend(char *dest, const char *src, uint32_t destlen);
106
107/* Ensure that only our stub implementations are used, not standard C */
108#ifndef _STUB_IMPLEMENTATION_
109#define malloc _do_not_use_standard_malloc
110#define free _do_not_use_standard_free
111#define memcmp _do_not_use_standard_memcmp
112#define memcpy _do_not_use_standard_memcpy
113#define memset _do_not_use_standard_memset
114#endif
115
116#endif  /* VBOOT_REFERENCE_UTILITY_H_ */
117