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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
// String manipulation functions.
//
// Copyright (C) 2008-2013 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "stacks.h" // yield
#include "string.h" // memcpy
#include "farptr.h" // SET_SEG
/****************************************************************
* String ops
****************************************************************/
// Sum the bytes in the specified area.
u8
checksum_far(u16 buf_seg, void *buf_far, u32 len)
{
SET_SEG(ES, buf_seg);
u32 i;
u8 sum = 0;
for (i=0; i<len; i++)
sum += GET_VAR(ES, ((u8*)buf_far)[i]);
return sum;
}
u8
checksum(void *buf, u32 len)
{
return checksum_far(GET_SEG(SS), buf, len);
}
size_t
strlen(const char *s)
{
if (__builtin_constant_p(s))
return __builtin_strlen(s);
const char *p = s;
while (*p)
p++;
return p-s;
}
int
memcmp_far(u16 s1seg, const void *s1, u16 s2seg, const void *s2, size_t n)
{
while (n--) {
int d = GET_FARVAR(s1seg, *(u8*)s1) - GET_FARVAR(s2seg, *(u8*)s2);
if (d)
return d < 0 ? -1 : 1;
s1++;
s2++;
}
return 0;
}
// Compare two areas of memory.
int
memcmp(const void *s1, const void *s2, size_t n)
{
while (n) {
if (*(u8*)s1 != *(u8*)s2)
return *(u8*)s1 < *(u8*)s2 ? -1 : 1;
s1++;
s2++;
n--;
}
return 0;
}
// Compare two strings.
int
strcmp(const char *s1, const char *s2)
{
for (;;) {
if (*s1 != *s2)
return *s1 < *s2 ? -1 : 1;
if (! *s1)
return 0;
s1++;
s2++;
}
}
inline void
memset_far(u16 d_seg, void *d_far, u8 c, size_t len)
{
SET_SEG(ES, d_seg);
asm volatile(
"rep stosb %%es:(%%di)"
: "+c"(len), "+D"(d_far)
: "a"(c), "m" (__segment_ES)
: "cc", "memory");
}
inline void
memset16_far(u16 d_seg, void *d_far, u16 c, size_t len)
{
len /= 2;
SET_SEG(ES, d_seg);
asm volatile(
"rep stosw %%es:(%%di)"
: "+c"(len), "+D"(d_far)
: "a"(c), "m" (__segment_ES)
: "cc", "memory");
}
void *
memset(void *s, int c, size_t n)
{
while (n)
((char *)s)[--n] = c;
return s;
}
void memset_fl(void *ptr, u8 val, size_t size)
{
if (MODESEGMENT)
memset_far(FLATPTR_TO_SEG(ptr), (void*)(FLATPTR_TO_OFFSET(ptr)),
val, size);
else
memset(ptr, val, size);
}
inline void
memcpy_far(u16 d_seg, void *d_far, u16 s_seg, const void *s_far, size_t len)
{
SET_SEG(ES, d_seg);
u16 bkup_ds;
asm volatile(
"movw %%ds, %w0\n"
"movw %w4, %%ds\n"
"rep movsb (%%si),%%es:(%%di)\n"
"movw %w0, %%ds"
: "=&r"(bkup_ds), "+c"(len), "+S"(s_far), "+D"(d_far)
: "r"(s_seg), "m" (__segment_ES)
: "cc", "memory");
}
inline void
memcpy_fl(void *d_fl, const void *s_fl, size_t len)
{
if (MODESEGMENT)
memcpy_far(FLATPTR_TO_SEG(d_fl), (void*)FLATPTR_TO_OFFSET(d_fl)
, FLATPTR_TO_SEG(s_fl), (void*)FLATPTR_TO_OFFSET(s_fl)
, len);
else
memcpy(d_fl, s_fl, len);
}
void *
#undef memcpy
memcpy(void *d1, const void *s1, size_t len)
#if MODESEGMENT == 0
#define memcpy __builtin_memcpy
#endif
{
SET_SEG(ES, GET_SEG(SS));
void *d = d1;
if (((u32)d1 | (u32)s1 | len) & 3) {
// non-aligned memcpy
asm volatile(
"rep movsb (%%esi),%%es:(%%edi)"
: "+c"(len), "+S"(s1), "+D"(d)
: "m" (__segment_ES) : "cc", "memory");
return d1;
}
// Common case - use 4-byte copy
len /= 4;
asm volatile(
"rep movsl (%%esi),%%es:(%%edi)"
: "+c"(len), "+S"(s1), "+D"(d)
: "m" (__segment_ES) : "cc", "memory");
return d1;
}
// Copy to/from memory mapped IO. IO mem is very slow, so yield
// periodically.
void
iomemcpy(void *d, const void *s, u32 len)
{
ASSERT32FLAT();
yield();
while (len > 3) {
u32 copylen = len;
if (copylen > 2048)
copylen = 2048;
copylen /= 4;
len -= copylen * 4;
asm volatile(
"rep movsl (%%esi),%%es:(%%edi)"
: "+c"(copylen), "+S"(s), "+D"(d)
: : "cc", "memory");
yield();
}
if (len)
// Copy any remaining bytes.
memcpy(d, s, len);
}
void *
memmove(void *d, const void *s, size_t len)
{
if (s >= d)
return memcpy(d, s, len);
d += len-1;
s += len-1;
while (len--) {
*(char*)d = *(char*)s;
d--;
s--;
}
return d;
}
// Copy a string - truncating it if necessary.
char *
strtcpy(char *dest, const char *src, size_t len)
{
char *d = dest;
while (--len && *src != '\0')
*d++ = *src++;
*d = '\0';
return dest;
}
// locate first occurrence of character c in the string s
char *
strchr(const char *s, int c)
{
for (; *s; s++)
if (*s == c)
return (char*)s;
return NULL;
}
// Remove any trailing blank characters (spaces, new lines, carriage returns)
char *
nullTrailingSpace(char *buf)
{
int len = strlen(buf);
char *end = &buf[len-1];
while (end >= buf && *end <= ' ')
*(end--) = '\0';
while (*buf && *buf <= ' ')
buf++;
return buf;
}
|
