diff --git a/src/assembler/AST.rs b/src/assembler/AST.rs
index 57e4efc..8d1e15c 100644
--- a/src/assembler/AST.rs
+++ b/src/assembler/AST.rs
@@ -31,5 +31,5 @@ pub enum Operation {
     CALL(RegisterMem, Const),
 
     // J Type
-    JAL(RegisterMem, RegisterMem, Word),
+    JAL(RegisterMem, RegisterMem, Const),
 }
diff --git a/src/assembler/encoder.rs b/src/assembler/encoder.rs
index 02108fd..7b949e8 100644
--- a/src/assembler/encoder.rs
+++ b/src/assembler/encoder.rs
@@ -1,17 +1,18 @@
-use super::{SymbolTable, AST::*};
+use super::{AST::*};
 use crate::cpu::{get_num, OP::*, get_memo};
 
 pub trait CodeFormat {
-    fn encode_op(op: &Operation, sy: &SymbolTable) -> Option<Self>
+    fn encode_op(op: &Operation, sy: &SymbolTable, current_pc: u16) -> Option<Self>
     where
         Self: Sized;
 }
 
-struct SyWrap<'a>(&'a SymbolTable);
+#[derive(Debug)]
+pub struct SymbolTable(pub Vec<(String, u16)>);
 
-impl SyWrap<'_> {
+impl SymbolTable {
     pub fn lookup(&self, query: &str) -> u16 {
-        let SyWrap(sy) = self;
+        let SymbolTable(sy) = self;
 
         for (name, loc) in sy.into_iter() {
             if query == (*name) {
@@ -26,8 +27,8 @@ impl SyWrap<'_> {
 }
 
 impl CodeFormat for u16 {
-    fn encode_op(op: &Operation, sy: &SymbolTable) -> Option<Self> {
-        let sy = SyWrap(sy);
+    fn encode_op(op: &Operation, sy: &SymbolTable, current_pc: u16) -> Option<Self> {
+        println!("encoding {:?}", op);
         match op {
             Operation::NOP => Some(0b0000000000000000),
             Operation::HALT => Some(0b1111111111111111),
@@ -131,7 +132,10 @@ impl CodeFormat for u16 {
             Operation::JAL(r1, r2, c) => {
                 let r1b = get_num(&r1)? as u16;
                 let r2b = get_num(&r2)? as u16;
-                let cb = (*c) as u16;
+                let cb = match c {
+                    Const::CS(label) => current_pc - sy.lookup(&label),
+                    Const::C(n) => (*n) as u16,
+                };
                 return Some((0b1010 << 12) + (r1b << 8) + (r2b << 4) + cb);
             },
         }
diff --git a/src/assembler/mod.rs b/src/assembler/mod.rs
index df8d06c..535d247 100644
--- a/src/assembler/mod.rs
+++ b/src/assembler/mod.rs
@@ -4,6 +4,7 @@ pub mod parser;
 mod tests;
 
 
+use encoder::{SymbolTable};
 use encoder::CodeFormat;
 
 use parser::Section;
@@ -13,7 +14,6 @@ use crate::loader::unloader::make_string;
 
 use self::parser::SectionContent;
 
-type SymbolTable = Vec<(String, u16)>;
 
 impl Section {
     fn get_size(&self) -> usize {
@@ -30,11 +30,15 @@ impl Section {
     }
 
     fn to_binary(&self, sy: &SymbolTable) -> Option<Vec<u16>> {
+        let own_address = sy.lookup(&self.name);
         match &self.content {
             SectionContent::Code(c) => {
                 let mut res = vec![];
+                let mut pc = own_address;
                 for op in c.iter() {
-                    res.push(CodeFormat::encode_op(op, sy)?);
+                    println!("converting {:?}", op);
+                    res.push(CodeFormat::encode_op(op, sy, pc)?);
+                    pc += 1;
                 }
                 return Some(res);
 
@@ -75,7 +79,7 @@ fn sort_sections(sections: Vec<Section>) -> Option<Vec<Section>> {
     return Some(res);
 }
 
-fn make_symbol_table(sections: &Vec<Section>) -> Option<SymbolTable> {
+fn make_symbol_table<'a>(sections: &'a Vec<Section>) -> Option<SymbolTable> {
    
     let mut res = vec![];
     let mut pos : u16 = 0;
@@ -86,7 +90,7 @@ fn make_symbol_table(sections: &Vec<Section>) -> Option<SymbolTable> {
     }
     
 
-    return Some(res);
+    return Some(SymbolTable(res));
    
 }
 
diff --git a/src/assembler/parser.rs b/src/assembler/parser.rs
index 28a27bb..86a885e 100644
--- a/src/assembler/parser.rs
+++ b/src/assembler/parser.rs
@@ -191,7 +191,7 @@ fn parse_code_line(i: &str) -> Result<Operation, ParseError> {
     // every operation has at most 3 arguments
     let mut bits = i.split_whitespace();
     println!("current parse code line: {}", i);
-    let Some(op) = bits.next() else {return Err(ParseError::BadSectionContent)};
+    let Some(op) = bits.next() else {return Err(ParseError::BadInstruction)};
 
     // no type
     match op {
@@ -205,8 +205,8 @@ fn parse_code_line(i: &str) -> Result<Operation, ParseError> {
     };
 
     // I-type
-    let Some(r1) = bits.next() else {return Err(ParseError::BadSectionHeader)};
-    let Some(r2) = bits.next() else {return Err(ParseError::BadSectionHeader)};
+    let Some(r1) = bits.next() else {return Err(ParseError::BadInstruction)};
+    let Some(r2) = bits.next() else {return Err(ParseError::BadInstruction)};
 
     match op {
         "addi" => {
@@ -218,8 +218,43 @@ fn parse_code_line(i: &str) -> Result<Operation, ParseError> {
         "call" => {
             return Ok(CALL(r1.to_owned(), parse_const(r2)?));
         }
-        "halt" => {
-            return Ok(HALT);
+        _ => {}
+    }
+
+    let Some(r3) = bits.next() else {return Err(ParseError::BadInstruction)};
+
+    // R-type
+    match op {
+        "add" => {
+            return Ok(ADD(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+
+        "sub" => {
+            return Ok(SUB(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        "and" => {
+            return Ok(AND(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        "xor" => {
+            return Ok(XOR(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        "sll" => {
+            return Ok(SLL(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        "beq" => {
+            return Ok(BEQ(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        "bgt" => {
+            return Ok(BGT(r1.to_owned(), r2.to_owned(), r3.to_owned()));
+        }
+        _ => {}
+    }
+
+    // J-type
+    match op {
+
+        "jal" => {
+            return Ok(JAL(r1.to_owned(), r2.to_owned(), parse_const(&r3)?));
         }
         _ => {}
     }
diff --git a/src/cpu/decoder.rs b/src/cpu/decoder.rs
index e7269e9..9ce7741 100644
--- a/src/cpu/decoder.rs
+++ b/src/cpu/decoder.rs
@@ -35,7 +35,7 @@ pub fn decode(op: u16) -> OP {
     let c = Constant::from_be_bytes([(op & 0x00FF) as u8]);
     let c4 = Constant::from_be_bytes([(op & 0x000F) as u8]);
 
-    println!("opcode: {}", opcode);
+    // println!("opcode: {}", opcode);
 
     return match opcode {
         // todo: write a macro for every type (I-type, R-type)
diff --git a/src/cpu/mod.rs b/src/cpu/mod.rs
index 61d76ac..368bc6f 100644
--- a/src/cpu/mod.rs
+++ b/src/cpu/mod.rs
@@ -102,15 +102,23 @@ where
                 self.regs.pc += 1;
             }
             OP::BEQ(d, x0, x1) => {
-                if x0 == x1 {
+                let v0 = self.regs.get(x0).ok_or(InvalidRegister)?;
+                let v1 = self.regs.get(x1).ok_or(InvalidRegister)?;
+                if v0 == v1 {
                     let v = self.regs.get(d).ok_or(InvalidRegister)?;
                     self.regs.pc = v;
+                } else {
+                    self.regs.pc += 1;
                 }
             }
             OP::BGT(d, x0, x1) => {
-                if x0 > x1 {
+                let v0 = self.regs.get(x0).ok_or(InvalidRegister)?;
+                let v1 = self.regs.get(x1).ok_or(InvalidRegister)?;
+                if v0 > v1 {
                     let v = self.regs.get(d).ok_or(InvalidRegister)?;
                     self.regs.pc = v;
+                } else {
+                    self.regs.pc += 1;
                 }
             }
             OP::JAL(s0, s1, c) => {
diff --git a/src/main.rs b/src/main.rs
index 4b20198..37fd70e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,6 @@
+use std::env::Args;
+use std::env::args;
+
 use dekejit::assembler::parser;
 use dekejit::assembler::to_binary;
 use dekejit::cpu::IOBuffer;
@@ -7,8 +10,18 @@ use dekejit::loader::unloader::*;
 
 fn main() {
 
+        let args : Vec<String> = args().collect();
 
-        let code = std::fs::read_to_string("./tests/assembly/hello_world.grasm").unwrap();
+        if args.len() < 2 {
+            println!("Scialla");
+            return;
+        }
+
+        // let code = std::fs::read_to_string("./tests/assembly/hello_world.grasm").unwrap();
+        let code = match std::fs::read_to_string(&args[1]) {
+            Ok(p) => p,
+            Err(_) => {println!("Could not open file '{}'", &args[1]); return;}
+        };
 
         let mut parser = parser::Parser::new(code);
 
diff --git a/tests/assembly/loop.grasm b/tests/assembly/loop.grasm
new file mode 100644
index 0000000..6cd8ebb
--- /dev/null
+++ b/tests/assembly/loop.grasm
@@ -0,0 +1,16 @@
+
+.text main
+  addi t1 10
+  sub t0 t0 t0 ; set t0 = 0
+  addi t2 loop ; set t2 to loop's addr.
+  addi t3 end  ; set t3 to end's addr  
+
+.text loop
+  call t0 0    ; print t0
+  addi t0 1    ; t0 = t0 + 1;
+  beq t3 t1 t0
+  beq t2 zero zero
+
+.text end 
+  halt
+