最初コミット

main.c

@@ -0,0 +1,33 @@
+#if defined(__linux__)
+#define SYS_WRITE 1
+#define SYS_EXIT 60
+#elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
+#define SYS_WRITE 4
+#define SYS_EXIT 1
+#elif defined(__APPLE__)
+#define SYS_WRITE 0x2000004
+#define SYS_EXIT 0x2000001
+#endif
+
+char msg[] = "こんにちは、世界！\n";
+
+void _start() {
+  asm volatile(
+    ".intel_syntax noprefix\n"
+    "mov eax, %[sys_write]\n"
+    "mov edi, 1\n"
+    "mov rsi, offset msg\n"
+    "mov edx, %[len]\n"
+    "syscall\n"
+
+    "mov eax, %[sys_exit]\n"
+    "xor edi, edi\n"
+    "syscall\n"
+
+    ".att_syntax prefix\n"
+    :: [sys_write] "i" (SYS_WRITE),
+       [sys_exit] "i" (SYS_EXIT),
+       [len] "i" (sizeof(msg) - 1)
+    : "rax", "rdi", "rsi", "rdx", "rcx", "r11"
+  );
+}