add memset

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/src/common.c b/lib/src/common.c
new file mode 100644
index 0000000..2d122f5
--- /dev/null
+++ b/lib/src/common.c
@@ -0,0 +1,18 @@
+// Copyright (c) 2021 Johannes Stoelp
+
+#include <common.h>
+
+#if !defined(__linux__) || !defined(__x86_64__)
+#    error "Only supported on linux(x86_64)!"
+#endif
+
+void* memset(void* s, int c, size_t n) {
+    asm volatile(
+        "cld"
+        "\n"
+        "rep stosb"
+        : "+D"(s), "+c"(n)
+        : "a"(c)
+        : "memory");
+    return s;
+}