feat: port lua scripting language

programs/lib/libc/crt/crt1.c

@@ -0,0 +1,81 @@
+/*
+    * crt1.c
+    * Minimal C runtime startup for MontaukOS userspace programs
+    * Copyright (c) 2026 Daniel Hammer
+    *
+    * This startup shim is intentionally small: it fetches the raw
+    * command-line buffer from the kernel, tokenizes it into argc/argv,
+    * calls main(), then exits with main()'s return code.
+*/
+
+static inline long _sys1(long nr, long a1) {
+    long ret;
+    __asm__ volatile(
+        "mov %[a1], %%rdi\n\t"
+        "syscall"
+        : "=a"(ret)
+        : "a"(nr), [a1] "r"(a1)
+        : "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
+    return ret;
+}
+
+static inline long _sys2(long nr, long a1, long a2) {
+    long ret;
+    __asm__ volatile(
+        "mov %[a1], %%rdi\n\t"
+        "mov %[a2], %%rsi\n\t"
+        "syscall"
+        : "=a"(ret)
+        : "a"(nr), [a1] "r"(a1), [a2] "r"(a2)
+        : "rcx", "r11", "rdi", "rsi", "rdx", "r8", "r9", "r10", "memory");
+    return ret;
+}
+
+#define SYS_EXIT    0
+#define SYS_GETARGS 25
+
+extern int main(int argc, char** argv);
+
+void _start(void) {
+    char argbuf[256];
+    int len = (int)_sys2(SYS_GETARGS, (long)argbuf, (long)sizeof(argbuf));
+
+    char* argv[32];
+    int argc = 0;
+
+    argv[argc++] = (char*)"prog";
+
+    if (len > 0) {
+        if (len > 255) {
+            len = 255;
+        }
+
+        argbuf[len] = '\0';
+
+        char* p = argbuf;
+        while (*p != '\0' && argc < 31) {
+            while (*p == ' ') {
+                p++;
+            }
+
+            if (*p == '\0') {
+                break;
+            }
+
+            argv[argc++] = p;
+
+            while (*p != '\0' && *p != ' ') {
+                p++;
+            }
+
+            if (*p != '\0') {
+                *p++ = '\0';
+            }
+        }
+    }
+
+    argv[argc] = 0;
+
+    _sys1(SYS_EXIT, (long)main(argc, argv));
+    __builtin_unreachable();
+}