kernel: add stdlib.[ch]

1 files changed, 33 insertions, 0 deletions

diff --git a/kernel/stdlib.c b/kernel/stdlib.c
new file mode 100644
index 0000000..92fdec2
--- /dev/null
+++ b/kernel/stdlib.c
@@ -0,0 +1,33 @@
+#include "stdlib.h"
+
+void *memset(void *s, int c, size_t n)
+{
+    char *p = (char *) s;
+
+    for (size_t i = 0; i < n; i++, p++)
+        *p = (char) c;
+
+    return s;
+}
+
+/* overlap is not handled */
+void *memcpy(void *dest, void *src, size_t n)
+{
+    char *s = (char *) src;
+    char *d = (char *) dest;
+
+    for (size_t i = 0; i < n; i++, s++, d++)
+        *d = *s;
+
+    return dest;
+}
+
+int strncmp(const char *s1, const char *s2, size_t n)
+{
+    for (size_t i = 0; i < n; i++, s1++, s2++) {
+        if (*s1 < *s2) return -1;
+        if (*s1 > *s2) return 1;
+    }
+
+    return 0;
+}