First draft of a kernel side library, string.h & string.c implementing itoa

lib/string.c

@@ -0,0 +1,39 @@
+char *itoa(int value, char *str, int base) {
+    char *p = str;
+    char *p1, *p2;
+    unsigned int uvalue = value;
+    int negative = 0;
+
+    if (base < 2 || base > 36) {
+        *str = '\0';
+        return str;
+    }
+
+    if (value < 0 && base == 10) {
+        negative = 1;
+        uvalue = -value;
+    }
+
+    // Convert to string
+    do {
+        int digit = uvalue % base;
+        *p++ = (digit < 10) ? '0' + digit : 'a' + (digit - 10);
+        uvalue /= base;
+    } while (uvalue);
+
+    if (negative)
+        *p++ = '-';
+
+    *p = '\0';
+
+    // Reverse string
+    p1 = str;
+    p2 = p - 1;
+    while (p1 < p2) {
+        char tmp = *p1;
+        *p1++ = *p2;
+        *p2-- = tmp;
+    }
+
+    return str;
+}

lib/string.h

@@ -0,0 +1,7 @@
+#ifndef KERNEL_STRING_H
+#define KERNEL_STRING_H
+
+/** Integer to ascii */
+char *itoa(int value, char *str, int base);
+
+#endif