feat: port lua scripting language

programs/lib/libc/Makefile

@@ -19,6 +19,8 @@ endif
 
 LIBC_INC := ../../include/libc
 OBJDIR   := obj
+CRTDIR   := crt
+ASM_OBJS := $(OBJDIR)/setjmp.o
 
 # ---- Compiler flags ----
 
@@ -43,20 +45,49 @@ CFLAGS := \
     -isystem $(LIBC_INC) \
     -isystem $(shell $(CC) -print-file-name=include)
 
+CRT_CFLAGS := \
+    -std=gnu11 \
+    -O2 \
+    -nostdinc \
+    -ffreestanding \
+    -fno-stack-protector \
+    -fno-stack-check \
+    -fno-PIC \
+    -m64 \
+    -march=x86-64 \
+    -mno-red-zone \
+    -fno-tree-loop-distribute-patterns \
+    -isystem $(LIBC_INC) \
+    -isystem $(shell $(CC) -print-file-name=include)
+
 # ---- Target ----
 
 TARGET := liblibc.a
+CRT_OBJS := crt1.o crti.o crtn.o
 
 .PHONY: all clean
 
-all: $(TARGET)
+all: $(TARGET) $(CRT_OBJS)
 
-$(TARGET): $(OBJDIR)/libc.o
+$(TARGET): $(OBJDIR)/libc.o $(ASM_OBJS)
 	$(AR) rcs $@ $^
 
 $(OBJDIR)/libc.o: libc.c Makefile
 	@mkdir -p $(OBJDIR)
 	$(CC) $(CFLAGS) -c $< -o $@
 
+$(OBJDIR)/setjmp.o: setjmp.S Makefile
+	@mkdir -p $(OBJDIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+crt1.o: $(CRTDIR)/crt1.c Makefile
+	$(CC) $(CRT_CFLAGS) -c $< -o $@
+
+crti.o: $(CRTDIR)/crti.c Makefile
+	$(CC) $(CRT_CFLAGS) -c $< -o $@
+
+crtn.o: $(CRTDIR)/crtn.c Makefile
+	$(CC) $(CRT_CFLAGS) -c $< -o $@
+
 clean:
-	rm -rf $(OBJDIR) $(TARGET)
+	rm -rf $(OBJDIR) $(TARGET) $(CRT_OBJS)

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();
+}

programs/lib/libc/crt/crti.c

@@ -0,0 +1,7 @@
+/*
+    * crti.c
+    * Init section prologue placeholder for MontaukOS userspace
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+/* Empty for now: generic userspace CRT does not run global constructors yet. */

programs/lib/libc/crt/crtn.c

@@ -0,0 +1,7 @@
+/*
+    * crtn.c
+    * Init section epilogue placeholder for MontaukOS userspace
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+/* Empty for now: generic userspace CRT does not run global destructors yet. */

programs/lib/libc/setjmp.S

@@ -0,0 +1,40 @@
+/*
+    * setjmp.S
+    * setjmp/longjmp for x86_64 MontaukOS userspace
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+.text
+
+.global setjmp
+.type setjmp, @function
+setjmp:
+    mov %rbx,   (%rdi)
+    mov %rbp,  8(%rdi)
+    mov %r12, 16(%rdi)
+    mov %r13, 24(%rdi)
+    mov %r14, 32(%rdi)
+    mov %r15, 40(%rdi)
+    lea 8(%rsp), %rax
+    mov %rax,  48(%rdi)
+    mov (%rsp), %rax
+    mov %rax,  56(%rdi)
+    xor %eax, %eax
+    ret
+
+.global longjmp
+.type longjmp, @function
+longjmp:
+    mov %esi, %eax
+    test %eax, %eax
+    jnz 1f
+    inc %eax
+1:
+    mov   (%rdi), %rbx
+    mov  8(%rdi), %rbp
+    mov 16(%rdi), %r12
+    mov 24(%rdi), %r13
+    mov 32(%rdi), %r14
+    mov 40(%rdi), %r15
+    mov 48(%rdi), %rsp
+    jmp *56(%rdi)