d0f7acf9eb
An x86-64 operating system built from xv6, now largely rewritten: SMP, a copy-on-write root filesystem (SchFS), PCI/USB/virtio drivers, a TTF rasteriser, and a Linux-numbered syscall ABI. No history before this point -- the tree was never under version control. This commit exists so the rename that follows has something to undo to.
113 lines
1.6 KiB
C
113 lines
1.6 KiB
C
#include "types.h"
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#include "x86.h"
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void*
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memset(void *dst, int c, uint64 n)
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{
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uint64 c64;
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if ((addr_t)dst % 8 == 0 && n % 8 == 0) {
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c &= 0xFF;
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c64 = (uint64)c;
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c64 = (c64 << 56) | (c64 << 48) | (c64 << 40) | (c64 << 32) |
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(c64 << 24) | (c64 << 16) | (c64 << 8) | c64;
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stosq(dst, c64, n / 8);
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} else {
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stosb(dst, c, n);
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}
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return dst;
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}
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int
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memcmp(const void *v1, const void *v2, uint n)
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{
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const uchar *s1, *s2;
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s1 = v1;
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s2 = v2;
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while(n-- > 0){
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if(*s1 != *s2)
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return *s1 - *s2;
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s1++, s2++;
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}
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return 0;
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}
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void*
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memmove(void *dst, const void *src, uint n)
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{
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const char *s;
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char *d;
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s = src;
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d = dst;
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if(s < d && s + n > d){
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s += n;
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d += n;
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while(n-- > 0)
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*--d = *--s;
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} else
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while(n-- > 0)
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*d++ = *s++;
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return dst;
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}
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void*
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memcpy(void *dst, const void *src, uint n)
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{
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return memmove(dst, src, n);
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}
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int
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strncmp(const char *p, const char *q, uint n)
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{
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while(n > 0 && *p && *p == *q)
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n--, p++, q++;
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if(n == 0)
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return 0;
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return (uchar)*p - (uchar)*q;
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}
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char*
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strncpy(char *s, const char *t, int n)
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{
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char *os = s;
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while(n-- > 0 && (*s++ = *t++) != 0)
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;
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while(n-- > 0)
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*s++ = 0;
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return os;
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}
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char*
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safestrcpy(char *s, const char *t, int n)
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{
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char *os = s;
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if(n <= 0)
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return os;
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while(--n > 0 && (*s++ = *t++) != 0)
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;
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*s = 0;
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return os;
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}
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int
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strlen(const char *s)
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{
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int n;
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for(n = 0; s[n]; n++)
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;
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return n;
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}
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int
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strnlen(const char *s, int max)
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{
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int n;
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for(n = 0; n < max && s[n]; n++)
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;
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return n;
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}
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