[Add] laos base boot

laos/src/util/string.c

@@ -0,0 +1,93 @@
+#include "string.h"
+#include "latype.h"
+
+// mem ops could be more better
+// use loop unrolling
+
+void *memset(void *dst, int c, uint n) {
+    char *cdst = (char *) dst;
+    for (uint i = 0; i < n; ++i) {
+        cdst[i] = c;
+    }
+    return dst;
+}
+
+int memcmp(const void *m1, const void *m2, uint n) {
+    const uchar *s1, *s2;
+
+    s1 = m1;
+    s2 = m2;
+
+    while (n --> 0) {
+        if(*s1 != *s2)
+            return *s1 - *s2;
+        s1++;
+        s2++;
+    }
+
+    return 0;
+}
+
+void *memmove(void *dst, const void *src, uint n) {
+    const char *s;
+    char *d;
+
+    if(n == 0)
+        return dst;
+    
+    s = src;
+    d = dst;
+    if(s < d && s + n > d){
+        s += n;
+        d += n;
+        while(n-- > 0)
+            *--d = *--s;
+    } else
+        while(n-- > 0)
+            *d++ = *s++;
+
+    return dst;
+}
+
+void *memcpy(void *dst, const void *src, uint n) {
+    return memmove(dst, src, n);
+}
+
+int strncmp(const char *p, const char *q, uint n) {
+    while(n > 0 && *p && *p == *q)
+        n--, p++, q++;
+    if(n == 0)
+        return 0;
+    return (uchar)*p - (uchar)*q;
+}
+
+char *strncpy(char *s, const char *t, int n) {
+    char *os;
+
+    os = s;
+    while(n-- > 0 && (*s++ = *t++) != 0)
+        ;
+    while(n-- > 0)
+        *s++ = 0;
+    return os;
+}
+
+char *strcpy_s(char *s, const char *t, int n) {
+    char *os;
+
+    os = s;
+    if(n <= 0)
+        return os;
+    while(--n > 0 && (*s++ = *t++) != 0)
+        ;
+    *s = 0;
+    return os;
+}
+
+int strlen(const char *s) {
+    int n;
+
+    for(n = 0; s[n]; n++)
+        ;
+    return n;
+}