Pridana verze v0.1

kernel/string.c

@@ -0,0 +1,65 @@
+/*
+ * AsterOS Kernel
+ * Autor: Pavel Kalaš
+ * Rok: 2026
+ *
+ */
+
+/*
+ * Tento soubor obsahuje vlastni implementace zakladnich utility funkci.
+ * Kernel je pouziva misto standardni knihovny pro strlen, strcmp,
+ * memcpy a memset, aby zustal freestanding a plne pod kontrolou jadra.
+ */
+
+#include "string.h"
+
+usize aster_strlen(const char *s) {
+    usize n = 0;
+    while (s && s[n]) {
+        ++n;
+    }
+    return n;
+}
+
+int aster_strcmp(const char *a, const char *b) {
+    while (*a && (*a == *b)) {
+        ++a;
+        ++b;
+    }
+    return (unsigned char)*a - (unsigned char)*b;
+}
+
+int aster_strncmp(const char *a, const char *b, usize n) {
+    usize i;
+
+    for (i = 0; i < n; ++i) {
+        if (a[i] != b[i] || a[i] == '\0' || b[i] == '\0') {
+            return (unsigned char)a[i] - (unsigned char)b[i];
+        }
+    }
+
+    return 0;
+}
+
+void *aster_memcpy(void *dst, const void *src, usize n) {
+    usize i;
+    u8 *d = (u8 *)dst;
+    const u8 *s = (const u8 *)src;
+
+    for (i = 0; i < n; ++i) {
+        d[i] = s[i];
+    }
+
+    return dst;
+}
+
+void *aster_memset(void *dst, int v, usize n) {
+    usize i;
+    u8 *d = (u8 *)dst;
+
+    for (i = 0; i < n; ++i) {
+        d[i] = (u8)v;
+    }
+
+    return dst;
+}