1 // String manipulation functions.
3 // Copyright (C) 2008-2013 Kevin O'Connor <kevin@koconnor.net>
5 // This file may be distributed under the terms of the GNU LGPLv3 license.
7 #include "stacks.h" // yield
8 #include "string.h" // memcpy
9 #include "farptr.h" // SET_SEG
12 /****************************************************************
14 ****************************************************************/
16 // Sum the bytes in the specified area.
18 checksum_far(u16 buf_seg, void *buf_far, u32 len)
24 sum += GET_VAR(ES, ((u8*)buf_far)[i]);
29 checksum(void *buf, u32 len)
31 return checksum_far(GET_SEG(SS), buf, len);
37 if (__builtin_constant_p(s))
38 return __builtin_strlen(s);
46 memcmp_far(u16 s1seg, const void *s1, u16 s2seg, const void *s2, size_t n)
49 int d = GET_FARVAR(s1seg, *(u8*)s1) - GET_FARVAR(s2seg, *(u8*)s2);
51 return d < 0 ? -1 : 1;
58 // Compare two areas of memory.
60 memcmp(const void *s1, const void *s2, size_t n)
63 if (*(u8*)s1 != *(u8*)s2)
64 return *(u8*)s1 < *(u8*)s2 ? -1 : 1;
72 // Compare two strings.
74 strcmp(const char *s1, const char *s2)
78 return *s1 < *s2 ? -1 : 1;
87 memset_far(u16 d_seg, void *d_far, u8 c, size_t len)
91 "rep stosb %%es:(%%di)"
92 : "+c"(len), "+D"(d_far)
93 : "a"(c), "m" (__segment_ES)
98 memset16_far(u16 d_seg, void *d_far, u16 c, size_t len)
103 "rep stosw %%es:(%%di)"
104 : "+c"(len), "+D"(d_far)
105 : "a"(c), "m" (__segment_ES)
110 memset(void *s, int c, size_t n)
113 ((char *)s)[--n] = c;
117 void memset_fl(void *ptr, u8 val, size_t size)
120 memset_far(FLATPTR_TO_SEG(ptr), (void*)(FLATPTR_TO_OFFSET(ptr)),
123 memset(ptr, val, size);
127 memcpy_far(u16 d_seg, void *d_far, u16 s_seg, const void *s_far, size_t len)
134 "rep movsb (%%si),%%es:(%%di)\n"
136 : "=&r"(bkup_ds), "+c"(len), "+S"(s_far), "+D"(d_far)
137 : "r"(s_seg), "m" (__segment_ES)
142 memcpy_fl(void *d_fl, const void *s_fl, size_t len)
145 memcpy_far(FLATPTR_TO_SEG(d_fl), (void*)FLATPTR_TO_OFFSET(d_fl)
146 , FLATPTR_TO_SEG(s_fl), (void*)FLATPTR_TO_OFFSET(s_fl)
149 memcpy(d_fl, s_fl, len);
154 memcpy(void *d1, const void *s1, size_t len)
156 #define memcpy __builtin_memcpy
159 SET_SEG(ES, GET_SEG(SS));
161 if (((u32)d1 | (u32)s1 | len) & 3) {
162 // non-aligned memcpy
164 "rep movsb (%%esi),%%es:(%%edi)"
165 : "+c"(len), "+S"(s1), "+D"(d)
166 : "m" (__segment_ES) : "cc", "memory");
169 // Common case - use 4-byte copy
172 "rep movsl (%%esi),%%es:(%%edi)"
173 : "+c"(len), "+S"(s1), "+D"(d)
174 : "m" (__segment_ES) : "cc", "memory");
178 // Copy to/from memory mapped IO. IO mem is very slow, so yield
181 iomemcpy(void *d, const void *s, u32 len)
192 "rep movsl (%%esi),%%es:(%%edi)"
193 : "+c"(copylen), "+S"(s), "+D"(d)
198 // Copy any remaining bytes.
203 memmove(void *d, const void *s, size_t len)
206 return memcpy(d, s, len);
211 *(char*)d = *(char*)s;
219 // Copy a string - truncating it if necessary.
221 strtcpy(char *dest, const char *src, size_t len)
224 while (--len && *src != '\0')
230 // locate first occurrence of character c in the string s
232 strchr(const char *s, int c)
240 // Remove any trailing blank characters (spaces, new lines, carriage returns)
242 nullTrailingSpace(char *buf)
244 int len = strlen(buf);
245 char *end = &buf[len-1];
246 while (end >= buf && *end <= ' ')
248 while (*buf && *buf <= ' ')