diff --git a/Makefile b/Makefile
index 7ce8111..58dfed1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,12 @@
+TARGET := langc
+
+
+AFLAGS = -felf64 -F dwarf -g
+
+ifdef DEBUG
+	AFLAGS += -DDEBUG_BUILD
+endif
+
 SRCDIR := src
 COREDIR := $(SRCDIR)/core
 MATHDIR := $(COREDIR)/math
@@ -43,7 +52,8 @@ EXPRSRC := $(addprefix $(EXPRDIR)/, $(addsuffix .s, \
             create_expressions debug_expression \
             ))
 LEXSRC := $(addprefix $(LEXDIR)/, $(addsuffix .s, \
-            lexer lex_err lex_load lex_func \
+            lexer lex_err lex_load lex_func program_prologue \
+			func_boiler_plate \
             ))
 VARSRC := $(addprefix $(VARDIR)/, $(addsuffix .s, \
             get_vars insert_var \
@@ -59,26 +69,35 @@ SRC := $(SRCDIR)/start.s $(MATHSRC) $(STRSRC) $(PRINTSRC) $(FILESRC) $(VARSRC) $
 OBJDIR := obj
 OBJ := $(patsubst $(SRCDIR)/%.s,$(OBJDIR)/%.o,$(SRC))
 
-all: debug
+LIBOBJ := $(filter-out start.o, $(OBJ))
+LIBNAME := core.lang
+
+all: $(TARGET)
+
+lib: $(OBJ)
+	ar rcs $(LIBNAME) $(LIBOBJ)
 
 # Create output directories
 $(OBJDIR)/core/math $(OBJDIR)/core/string $(OBJDIR)/core/print $(OBJDIR)/core/mem $(OBJDIR)/core/syscall $(OBJDIR)/core/file $(OBJDIR)/parse/expression $(OBJDIR)/parse/token $(OBJDIR)/lexer $(OBJDIR)/lexer/vars $(OBJDIR)/global:
 	mkdir -p $@
 
 # Main target
-debug: $(OBJDIR) $(OBJDIR)/core/math $(OBJDIR)/core/string $(OBJDIR)/core/print $(OBJDIR)/core/mem $(OBJDIR)/core/syscall $(OBJDIR)/core/file $(OBJDIR)/parse/expression $(OBJDIR)/parse/token $(OBJDIR)/lexer $(OBJDIR)/lexer/vars $(OBJDIR)/global $(OBJ)
+$(TARGET): $(OBJDIR) $(OBJDIR)/core/math $(OBJDIR)/core/string $(OBJDIR)/core/print $(OBJDIR)/core/mem $(OBJDIR)/core/syscall $(OBJDIR)/core/file $(OBJDIR)/parse/expression $(OBJDIR)/parse/token $(OBJDIR)/lexer $(OBJDIR)/lexer/vars $(OBJDIR)/global $(OBJ)
 	ld -g -o $@ $(OBJ) -nostdlib -static
 
 # Fix: Use a more specific pattern rule that preserves paths
 $(OBJDIR)/%.o: $(SRCDIR)/%.s
 	mkdir -p $(dir $@)
-	nasm -felf64 -F dwarf -g $< -o $@
+	nasm $(AFLAGS) $< -o $@
 
 $(OBJDIR):
 	mkdir -p $@
 
 clean:
-	rm -rf $(OBJDIR) debug
+	rm -rf $(OBJDIR)
+
+fclean: clean
+	rm -rf $(TARGET)
 
 re: clean all
 
diff --git a/core.lang b/core.lang
new file mode 100644
index 0000000..1d30553
Binary files /dev/null and b/core.lang differ
diff --git a/src/core/mem/malloc.s b/src/core/mem/malloc.s
index 3688f44..736c6d0 100644
--- a/src/core/mem/malloc.s
+++ b/src/core/mem/malloc.s
@@ -50,6 +50,7 @@ malloc:                     ; RAX: long basic_malloc(RDI: size_t n)
     mov r8, rdi
     push rdi
 
+%ifdef DEBUG_BUILD
     mov rdi, success
     call putstr
     mov rdi, r8
@@ -63,6 +64,7 @@ malloc:                     ; RAX: long basic_malloc(RDI: size_t n)
     mov rdi, str_bytecnt
     call putendl
 
+%endif
     pop rax
     sub rax, rbx
     pop rbx
diff --git a/src/core/string/atoi.s b/src/core/string/atoi.s
new file mode 100644
index 0000000..2924bbd
--- /dev/null
+++ b/src/core/string/atoi.s
@@ -0,0 +1,15 @@
+section .text
+    extern strlen
+
+atoi:       ; rax: int (rdi: str*)
+    push rbp
+    mov rbp, rsp
+    sub rsp, 16
+    xor rax, rax
+    xor rcx, rcx
+    push rdi
+    call strlen
+    mov [rbp - 8], rax
+.loop:
+    
+.done:
diff --git a/src/global/function_table.s b/src/global/function_table.s
index 31d416e..3794311 100644
--- a/src/global/function_table.s
+++ b/src/global/function_table.s
@@ -1,16 +1,17 @@
 section .data
-    func_syms: db \
-        "putnumber", 0 \
+    putnumber_func: db "putnumber", 0
+    exit_func: db "exit", 0
 
     global ftable
-    ftable: dq 1,        \
-            func_syms
-    global func_prologue
-    func_prologue:  db "push rdi", 0
+    ftable: dq 2,        \
+        putnumber_func, \
+        exit_func
+
+    global func_call_prologue
+    func_call_prologue:  db "    push rdi", 0
 
     global func_call
-    func_call:      db "call ", 0
-
-    global func_epilogue
-    func_epilogue:  db "pop rdi", 0
+    func_call:      db "    call ", 0
 
+    global func_call_epilogue
+    func_call_epilogue:  db "    pop rdi", 0
diff --git a/src/inc/expression.s b/src/inc/expression.s
index 0fc591a..6129ba3 100644
--- a/src/inc/expression.s
+++ b/src/inc/expression.s
@@ -4,8 +4,8 @@
 %define EXPR_TOK_CNT 8
 %define EXPR_TOK 16
 
-
 ; struct expression size = 32
 ;   .type
 ;   .tok_count + 8
 ;   .tokens + 16
+
diff --git a/src/inc/function_table.s b/src/inc/function_table.s
index 531853a..1f58460 100644
--- a/src/inc/function_table.s
+++ b/src/inc/function_table.s
@@ -1,5 +1,5 @@
 %define FTABLE_SIZE     16
-%define FTABLE_COUNT    0
+%define FTABLE_COUNT    2
 %define FTABLE_SYM      8
 
 ; struct func_table
diff --git a/src/lexer/func_boiler_plate.s b/src/lexer/func_boiler_plate.s
new file mode 100644
index 0000000..bf74706
--- /dev/null
+++ b/src/lexer/func_boiler_plate.s
@@ -0,0 +1,26 @@
+section .text
+    extern putstr
+    extern putnumberendl
+
+    func_stack_alloc: db "    push rbp", 0xa, "    mov rbp, rsp", 0xa, "    sub rsp, ", 0
+    func_stack_dealloc: db "    mov rsp, rbp", 0xa, "    pop rbp", 0xa, 0
+    ret_inst:   db "    ret", 0xa, 0
+
+global func_prologue
+func_prologue:  ; (rdi: var_count)
+    mov rax, 8
+    imul rax, rdi
+    push rax
+    mov rdi, func_stack_alloc
+    call putstr
+    pop rdi
+    call putnumberendl
+    ret
+
+global func_epilogue
+func_epilogue:      ;
+    mov rdi, func_stack_dealloc
+    call putstr
+    mov rdi, ret_inst
+    call putstr
+    ret
diff --git a/src/lexer/lex_func.s b/src/lexer/lex_func.s
index 8ae5dcc..0a8d581 100644
--- a/src/lexer/lex_func.s
+++ b/src/lexer/lex_func.s
@@ -8,8 +8,8 @@
 section .data
     err_func_args_message: db FUNC_ERR, "invalid argument", 0
     extern func_call
-    extern func_prologue
-    extern func_epilogue
+    extern func_call_prologue
+    extern func_call_epilogue
     extern REG_RDI
 
 section .text
@@ -19,12 +19,14 @@ section .text
     extern lex_eundefined
     extern putstr
     extern putendl
+    extern putnumberendl
     extern exit
     extern look_up_var
     extern insert_mov
     extern load_var_reg
+    extern load_const_reg
 
-insert_func:    ; (rdi: name*, rsi: arg*)
+insert_func_with_const:    ; (rdi: name*, rsi: arg*)
     push rbp
     mov rbp, rsp
     sub rsp, 16
@@ -32,7 +34,32 @@ insert_func:    ; (rdi: name*, rsi: arg*)
     mov [rbp - 8], rdi  ; store name
     mov [rbp - 16], rsi ; store arg
 
-    mov rdi, func_prologue
+    mov rdi, func_call_prologue
+    call putendl
+
+    mov rdi, [rbp - 16]
+    mov rsi, REG_RDI
+    call load_const_reg
+    mov rdi, func_call
+    call putstr
+    mov rdi, [rbp - 8]
+    call putendl
+    mov rdi, func_call_epilogue
+    call putendl
+
+    mov rsp, rbp
+    pop rbp
+    ret
+
+insert_func_with_var:    ; (rdi: name*, rsi: arg*)
+    push rbp
+    mov rbp, rsp
+    sub rsp, 16
+
+    mov [rbp - 8], rdi  ; store name
+    mov [rbp - 16], rsi ; store arg
+
+    mov rdi, func_call_prologue
     call putendl
 
     mov rdi, [rbp - 16]
@@ -42,7 +69,7 @@ insert_func:    ; (rdi: name*, rsi: arg*)
     call putstr
     mov rdi, [rbp - 8]
     call putendl
-    mov rdi, func_epilogue
+    mov rdi, func_call_epilogue
     call putendl
 
     mov rsp, rbp
@@ -59,8 +86,7 @@ err_func_args:
 global look_up_func
 look_up_func:           ; (rdi: name*)
     push rbx
-    lea rdx, [ftable]
-    mov rbx, [rdx + FTABLE_COUNT]
+    mov rbx, FTABLE_COUNT
     xor rcx, rcx
 
 .search_func:
@@ -68,9 +94,14 @@ look_up_func:           ; (rdi: name*)
     je .done_false
 
     ; rdi still contains name
-    mov rsi, [rdx + FTABLE_SYM]
+    push rcx
+    mov rax, FTABLE_SYM
+    inc rcx
+    imul rax, rcx
+    mov rsi, [ftable + rax]
     call strcmp
     test rax, rax
+    pop rcx
     jz .done_true
 
     inc rcx
@@ -132,6 +163,10 @@ lex_func_call:           ;   rax: bool (rdi :lex *)
     call err_func_args
 
 .arg_const:
+    mov rdi, [rbp - 24]
+    mov rsi, [rsi + TOK_VALUE]
+    call insert_func_with_const
+    jmp .done
 
 .arg_var:
     mov rdi, [rbp - 8]
@@ -139,7 +174,7 @@ lex_func_call:           ;   rax: bool (rdi :lex *)
     call look_up_var
     mov rsi, rax
     mov rdi, [rbp - 24]
-    call insert_func
+    call insert_func_with_var
 
 
 .done:
diff --git a/src/lexer/lexer.s b/src/lexer/lexer.s
index 19f92ac..465c1d2 100644
--- a/src/lexer/lexer.s
+++ b/src/lexer/lexer.s
@@ -8,15 +8,19 @@ section .text
     extern err_malloc
     extern exit
     extern putstr
+    extern putendl
 
     extern create_expressions
     extern strcmp
     extern get_vars
     extern lex_load
     extern lex_func_call
-
     extern lex_eundefined
 
+    extern func_prologue
+    extern func_epilogue
+
+    extern program_prologue
 
 global lex
 lex:            ; rax: lex* (rdi: char *file_content)
@@ -42,11 +46,19 @@ lex:            ; rax: lex* (rdi: char *file_content)
 
     mov rdi, [rbp - 24]
     mov [rdi + LEX_EXPR], rax
-    mov rax, [rbp - 16]
-    mov [rdi + LEX_EXPR_CNT], rax
+    mov eax, dword [rbp - 16]
+    mov dword [rdi + LEX_EXPR_CNT], eax
 
     call get_vars
 
+    mov rdi, [rbp - 24]
+    call program_prologue
+
+    mov rdi, [rbp - 24]
+    mov edi, dword [rdi + LEX_VAR_CNT]
+
+    call func_prologue
+
     mov rax, [rbp - 24]
     lea rcx, [rax + LEX_EXPR_IDX]
 
@@ -71,6 +83,7 @@ lex:            ; rax: lex* (rdi: char *file_content)
 
     jmp .process_expressions
 .done:
+    call func_epilogue
     pop rbx
     mov rsp, rbp
     pop rbp
diff --git a/src/lexer/program_prologue.s b/src/lexer/program_prologue.s
new file mode 100644
index 0000000..e56e3bb
--- /dev/null
+++ b/src/lexer/program_prologue.s
@@ -0,0 +1,96 @@
+%include "./src/inc/lexer.s"
+%include "./src/inc/token.s"
+%include "./src/inc/expression.s"
+
+section .data
+    section_text: db "section .text", 0xa, 0
+    program_start: db "global _start", 0xa, "_start:", 0xa, 0
+    extern_str: db "extern ", 0
+
+
+section .text
+    extern putendl
+    extern putstr
+
+    global program_prologue
+
+print_section_text:
+    mov rdi, section_text
+    call putstr
+    ret
+
+print_program_start:
+    mov rdi, program_start
+    call putendl
+    ret
+
+declare_extern:         ; (rdi: func_name*)
+    push rdi
+    mov rdi, extern_str
+    call putstr
+    pop rdi
+    call putendl
+    ret
+
+declare_extern_func:    ;(rdi: lex*)
+    push rbp
+    mov rbp, rsp
+
+    sub rsp, 16
+
+    push rbx
+    xor rcx, rcx
+
+    mov rax, [rdi + LEX_EXPR]
+    mov [rbp - 8], rax
+    mov eax, dword [rdi + LEX_EXPR_CNT]
+    mov [rbp - 12], eax
+.loop:
+    cmp ecx, [rbp - 12]
+    je .loop_end
+    mov rbx, [rbp - 8]
+    mov rax, EXPR_SIZE
+    imul rax, rcx
+    lea rbx, [rbx + rax]
+    mov r8, [rbx + EXPR_TOK_CNT]
+    mov rbx, [rbx + EXPR_TOK]
+    push rcx
+    xor rcx, rcx
+.loop_tokens:
+    cmp rcx, r8
+    je .loop_tokens_end
+    mov rax, SIZE_TOK
+    imul rax, rcx
+    lea rax, [rbx + rax]
+    mov rdx, TOK_FUNC
+    cmp rdx, qword [rax + TOK_TYPE]
+    jne .dont_print
+    mov rdi, [rax + TOK_VALUE]
+    push rcx
+    push r8
+    call declare_extern
+    pop r8
+    pop rcx
+.dont_print:
+    inc rcx
+    jmp .loop_tokens
+.loop_tokens_end:
+    pop rcx
+    inc rcx
+    jmp .loop
+
+.loop_end:
+    pop rbx
+
+    mov rsp, rbp
+    pop rbp
+    ret
+
+program_prologue:   ;(rdi: lex*)
+    push rdi
+    mov rdi, section_text
+    call putendl
+    pop rdi
+    call declare_extern_func
+    call print_program_start
+    ret
diff --git a/src/lexer/vars/get_vars.s b/src/lexer/vars/get_vars.s
index 8d93305..d71c1ff 100644
--- a/src/lexer/vars/get_vars.s
+++ b/src/lexer/vars/get_vars.s
@@ -124,7 +124,8 @@ get_vars:           ; (rdi: lex*)
     push rcx
 .loop_expr:
     pop rcx
-    cmp ecx, dword [rdi + LEX_EXPR_CNT]
+    mov ebx, dword [rbp - 8]
+    cmp ecx, ebx
     je .done
     mov rax, EXPR_SIZE
     mul rcx
@@ -156,7 +157,9 @@ get_vars:           ; (rdi: lex*)
     pop rcx
     pop rdi
     cmp rax, 1
+    pop rax
     je .skip_alloc
+    push rax
     mov rax, VAR_SIZE
     mul r9
     lea rbx, [rbx + rax]
diff --git a/src/lexer/vars/insert_var.s b/src/lexer/vars/insert_var.s
index 1dd99c4..4762477 100644
--- a/src/lexer/vars/insert_var.s
+++ b/src/lexer/vars/insert_var.s
@@ -2,10 +2,10 @@
 
 section .data
 
-    INST_MOV: db "mov ", 0
-    INST_ADD: db "add ", 0
-    INST_SUB: db "sub ", 0
-    INST_XOR: db "xor ", 0
+    INST_MOV: db "    mov ", 0
+    INST_ADD: db "    add ", 0
+    INST_SUB: db "    sub ", 0
+    INST_XOR: db "    xor ", 0
 
     OPEN_STACK_VAR: db "[rbp-", 0
     CLOSE_STACK_VAR: db "]", 0
@@ -14,6 +14,7 @@ section .data
 section .text
     extern putstr
     extern putnumber
+    extern putnumberendl
     extern putchar
     extern putendl
     extern VAL_CONST
@@ -25,7 +26,6 @@ section .text
     extern REG_RAX
     extern REG_RDI
 
-
 global insert_xor
 insert_xor:
     mov rdi, INST_XOR
@@ -86,6 +86,24 @@ load_reg_var:           ; (rdi: OFF_S, rsi: REG*)
 
     ret
 
+global load_const_reg
+load_const_reg:           ; (rdi: const*, rsi: REG*)
+    push rdi
+    push rsi
+
+    call insert_mov
+
+    pop rdi
+    call putstr
+
+    mov rdi, SEP_INST
+    call putstr
+
+    pop rdi
+    call insert_const_endl
+
+    ret
+
 global load_var_reg
 load_var_reg:           ; (rdi: OFF_S, rsi: REG*)
     push rdi
@@ -237,7 +255,13 @@ sub_rax_var:            ; (rdi: OFF_S)
 
     ret
 
-global insert_var
+insert_const_endl:             ; (rdi: const*)
+    push rdi
+    call putendl
+    pop rdi
+
+    ret
+
 insert_var_endl:             ; (rdi: OFF_S)
     push rdi
     mov rdi, OPEN_STACK_VAR
diff --git a/src/parse/expression/create_expressions.s b/src/parse/expression/create_expressions.s
index 07541d9..ab6f36b 100644
--- a/src/parse/expression/create_expressions.s
+++ b/src/parse/expression/create_expressions.s
@@ -107,9 +107,11 @@ create_expressions:         ; rax: exp* (rdi: char *filecontent, rsi: *cnt)
     mov rax, EXPR_SIZE
     mul rcx
     lea rdi, [rbx + rax]
+%ifdef DEBUG_BUILD
     push rcx
     call print_expression
     pop rcx
+%endif
     inc rcx
     jmp .expr_loop_print
 
diff --git a/src/parse/tokenizer.s b/src/parse/tokenizer.s
index 2f9e2ee..b87dfd2 100644
--- a/src/parse/tokenizer.s
+++ b/src/parse/tokenizer.s
@@ -1,9 +1,9 @@
 section .text
 
 is_space:           ; rax: bool (rdi: c)
-    cmp c, 8
+    cmp rdi, 8
     jl .false
-    cmp c, 13
+    cmp rdi, 13
     je .false
 .true:
     mov rax, 1
diff --git a/src/start.s b/src/start.s
index 5a1d8e5..6e20e0f 100644
--- a/src/start.s
+++ b/src/start.s
@@ -19,68 +19,24 @@ print_usage:
     call putstr
 
 _start:
+    pop rdi
+    cmp rdi, 2
+    jne err_args
+    mov rdi, [rsp + 8]          ; argv[1]
     push rbp
     mov rbp, rsp
+
     sub rsp, 16
 
-    mov rdi, 1
-    call vec_create
+    call get_file_content
     mov rdi, rax
+    mov [rbp - 8], rax
 
-    xor rcx, rcx
-    mov rbx, 90
-    mov r8, ' '
+    mov rdi, rax
+    call lex
 
-.loop:
-    cmp rcx, rbx
-    je .done
-    push rcx
-    push r8
-    mov byte [rbp - 4], r8b
-    lea rsi, [rbp - 4]
-    push rdi
-    call vec_push
-    pop rdi
-    pop r8
-    pop rcx
-    inc r8
-    inc rcx
-    jmp .loop
-.done:
-    push rdi
-    call vec_pop
-    pop rdi
-    push rdi
-    mov rdi, [rdi + 16]
-    call putstr
-    pop rdi
-    lea rsi, [rbp - 1]
-    mov rdx, 88
-    call vec_get
-    test rax, rax
-    jz done
-
-    mov dil, byte [rbp - 1]
-    call putchar
-
-;    pop rdi
-;    cmp rdi, 2
-;    jne err_args
-;    mov rdi, [rsp + 8]          ; argv[1]
-;    push rbp
-;    mov rbp, rsp
-;
-;    sub rsp, 16
-;
-;    call get_file_content
-;    mov rdi, rax
-;    mov [rbp - 8], rax
-;
-;    mov rdi, rax
-;    call lex
-;
-;    mov rsp, rbp
-;    pop rbp
+    mov rsp, rbp
+    pop rbp
 
 done:
     xor rdi, rdi
diff --git a/test.c b/test.c
deleted file mode 100644
index 50090b9..0000000
--- a/test.c
+++ /dev/null
@@ -1,24 +0,0 @@
-#include <stdio.h>
-
-int main(int argc, char **argv) {
-
-    int a = 17;
-
-    switch (a) {
-        case 1:
-            break ;
-        case 2:
-            break ;
-        case 3:
-            break ;
-        case 4:
-            break ;
-        case 5:
-            break ;
-        case 6:
-            break ;
-        case 17:
-            a = 0xfffaaaaf;
-            break ;
-    }
-}
diff --git a/test.lang b/test.lang
index fe95113..352d7b3 100644
--- a/test.lang
+++ b/test.lang
@@ -1,3 +1,7 @@
 a = 6
 b = 5 - 2 + 6 + a
 putnumber b
+c = b + a
+putnumber c
+a = 0
+exit 1