1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/* Copyright 2021 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.
*/
/* Utility functions for Chrome EC within the FIPS boundary */
#include "common.h"
#include "console.h"
#include "util.h"
__stdlib_compat size_t strlen(const char *s)
{
int len = 0;
while (*s++)
len++;
return len;
}
__stdlib_compat int memcmp(const void *s1, const void *s2, size_t len)
{
const char *sa = s1;
const char *sb = s2;
int diff = 0;
while (len-- > 0) {
diff = *(sa++) - *(sb++);
if (diff)
return diff;
}
return 0;
}
__stdlib_compat void *memcpy(void *dest, const void *src, size_t len)
{
char *d = (char *)dest;
const char *s = (const char *)src;
uint32_t *dw;
const uint32_t *sw;
char *head;
char * const tail = (char *)dest + len;
/* Set 'body' to the last word boundary */
uint32_t * const body = (uint32_t *)((uintptr_t)tail & ~3);
if (((uintptr_t)dest & 3) != ((uintptr_t)src & 3)) {
/* Misaligned. no body, no tail. */
head = tail;
} else {
/* Aligned */
if ((uintptr_t)tail < (((uintptr_t)d + 3) & ~3))
/* len is shorter than the first word boundary */
head = tail;
else
/* Set 'head' to the first word boundary */
head = (char *)(((uintptr_t)d + 3) & ~3);
}
/* Copy head */
while (d < head)
*(d++) = *(s++);
/* Copy body */
dw = (uint32_t *)d;
sw = (uint32_t *)s;
while (dw < body)
*(dw++) = *(sw++);
/* Copy tail */
d = (char *)dw;
s = (const char *)sw;
while (d < tail)
*(d++) = *(s++);
return dest;
}
__stdlib_compat __visible void *memset(void *dest, int c, size_t len)
{
char *d = (char *)dest;
uint32_t cccc;
uint32_t *dw;
char *head;
char * const tail = (char *)dest + len;
/* Set 'body' to the last word boundary */
uint32_t * const body = (uint32_t *)((uintptr_t)tail & ~3);
c &= 0xff; /* Clear upper bits before ORing below */
cccc = c | (c << 8) | (c << 16) | (c << 24);
if ((uintptr_t)tail < (((uintptr_t)d + 3) & ~3))
/* len is shorter than the first word boundary */
head = tail;
else
/* Set 'head' to the first word boundary */
head = (char *)(((uintptr_t)d + 3) & ~3);
/* Copy head */
while (d < head)
*(d++) = c;
/* Copy body */
dw = (uint32_t *)d;
while (dw < body)
*(dw++) = cccc;
/* Copy tail */
d = (char *)dw;
while (d < tail)
*(d++) = c;
return dest;
}
__stdlib_compat void *memmove(void *dest, const void *src, size_t len)
{
if ((uintptr_t)dest <= (uintptr_t)src ||
(uintptr_t)dest >= (uintptr_t)src + len) {
/*
* Start of destination doesn't overlap source, so just use
* memcpy().
*/
return memcpy(dest, src, len);
}
{
/* Need to copy from tail because there is overlap. */
char *d = (char *)dest + len;
const char *s = (const char *)src + len;
uint32_t *dw;
const uint32_t *sw;
char *head;
char * const tail = (char *)dest;
/* Set 'body' to the last word boundary */
uint32_t * const body = (uint32_t *)(((uintptr_t)tail+3) & ~3);
if (((uintptr_t)dest & 3) != ((uintptr_t)src & 3)) {
/* Misaligned. no body, no tail. */
head = tail;
} else {
/* Aligned */
if ((uintptr_t)tail > ((uintptr_t)d & ~3))
/* Shorter than the first word boundary */
head = tail;
else
/* Set 'head' to the first word boundary */
head = (char *)((uintptr_t)d & ~3);
}
/* Copy head */
while (d > head)
*(--d) = *(--s);
/* Copy body */
dw = (uint32_t *)d;
sw = (uint32_t *)s;
while (dw > body)
*(--dw) = *(--sw);
/* Copy tail */
d = (char *)dw;
s = (const char *)sw;
while (d > tail)
*(--d) = *(--s);
return dest;
}
}
void reverse(void *dest, size_t len)
{
int i;
uint8_t *start = dest;
uint8_t *end = start + len;
for (i = 0; i < len / 2; ++i) {
uint8_t tmp = *start;
*start++ = *--end;
*end = tmp;
}
}
__stdlib_compat int strncmp(const char *s1, const char *s2, size_t n)
{
while (n--) {
if (*s1 != *s2)
return *s1 - *s2;
if (!*s1)
break;
s1++;
s2++;
}
return 0;
}
static void always_memset_impl(volatile char *s, int c, size_t n)
{
while (n--)
*s++ = c;
}
void *always_memset(void *s, int c, size_t n)
{
always_memset_impl(s, c, n);
return s;
}
|
