utility.h revision a3454fcaa415b2c99514c44eebee7325fe0d1f9f 
1/* Copyright (c) 2010 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/* Helper functions/wrappers for memory allocations, manipulation and
7 * comparison.
8 */
9
10#ifndef VBOOT_REFERENCE_UTILITY_H_
11#define VBOOT_REFERENCE_UTILITY_H_
12
13#include "sysincludes.h"
14
15/* Debug and error output */
16#ifdef VBOOT_DEBUG
17#define VBDEBUG(params) VbExDebug params
18#else
19#define VBDEBUG(params)
20#endif
21
22#ifndef VBOOT_PERFORMANCE
23/* Define performance macros as nothing.  If you enable VBOOT_PERFORMANCE,
24 * you must define these macros in your platform's biosincludes.h.
25 *
26 * Intended usage for using a performance counter called 'foo':
27 *
28 * VBPERFSTART("foo")
29 * ...code to be tested...
30 * VBPERFEND("foo")
31 *
32 * Names should be <= 8 characters to be compatible with all platforms.
33 */
34#define VBPERFSTART(name)
35#define VBPERFEND(name)
36#endif
37
38#ifdef VBOOT_DEBUG
39#define VbAssert(expr) do { if (!(expr)) { \
40    VbExError("assert fail: %s at %s:%d\n", \
41              #expr, __FILE__, __LINE__); }} while(0)
42#else
43#define VbAssert(expr)
44#endif
45
46/* Combine [msw] and [lsw] uint16s to a uint32_t with its [msw] and
47 * [lsw] forming the most and least signficant 16-bit words.
48 */
49#define CombineUint16Pair(msw,lsw) (((msw) << 16) |     \
50                                    (((lsw)) & 0xFFFF))
51/* Return the minimum of (a) or (b). */
52#define Min(a, b) (((a) < (b)) ? (a) : (b))
53
54/* Compare [n] bytes in [src1] and [src2]
55 * Returns an integer less than, equal to, or greater than zero if the first [n]
56 * bytes of [src1] is found, respectively, to be less than, to match, or be
57 * greater than the first n bytes of [src2]. */
58int Memcmp(const void* src1, const void* src2, size_t n);
59
60/* Copy [n] bytes from [src] to [dest]. */
61void* Memcpy(void* dest, const void* src, uint64_t n);
62
63
64/* Implementations of the functions below must be built as part of the firmware
65 * and defined in lib/utility.c */
66
67/* Set [n] bytes starting at [s] to [c].  Returns dest. */
68void* Memset(void* dest, const uint8_t c, uint64_t n);
69
70/* Compare [n] bytes starting at [s1] with [s2] and return 0 if they
71 * match, 1 if they don't.  Returns 0 if n=0, since no bytes mismatched.
72 * Time taken to perform the comparison is only dependent on [n] and
73 * not on the relationship of the match between [s1] and [s2].
74 *
75 * Note that unlike Memcmp(), this only indicates inequality, not
76 * whether s1 is less than or greater than s2.
77 */
78int SafeMemcmp(const void* s1, const void* s2, size_t n);
79
80/* Buffer size required to hold the longest possible output of
81 * Uint64ToString() - that is, Uint64ToString(~0, 2). */
82#define UINT64_TO_STRING_MAX 65
83
84/* Convert a value to a string in the specified radix (2=binary, 10=decimal,
85 * 16=hex) and store it in <buf>, which is <bufsize> chars long.  If
86 * <zero_pad_width>, left-pads the string to at least that width with '0'.
87 * Returns the length of the stored string, not counting the terminating
88 * null. */
89uint32_t Uint64ToString(char *buf, uint32_t bufsize, uint64_t value,
90                        uint32_t radix, uint32_t zero_pad_width);
91
92/* Concatenate <src> onto <dest>, which has space for <destlen> characters
93 * including the terminating null.  Note that <dest> will always be
94 * null-terminated if <destlen> > 0.  Returns the number of characters
95 * used in <dest>, not counting the terminating null. */
96uint32_t Strncat(char *dest, const char *src, uint32_t destlen);
97
98/* Ensure that only our stub implementations are used, not standard C */
99#ifndef _STUB_IMPLEMENTATION_
100#define malloc _do_not_use_standard_malloc
101#define free _do_not_use_standard_free
102#define memcmp _do_not_use_standard_memcmp
103#define memcpy _do_not_use_standard_memcpy
104#define memset _do_not_use_standard_memset
105#endif
106
107#endif  /* VBOOT_REFERENCE_UTILITY_H_ */
108