From 5755ade839ceab4f788dc72fe820318e8edb9403 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20B=C3=B6ving?= <hargonix@gmail.com>
Date: Mon, 30 Nov 2020 18:28:25 +0100
Subject: [PATCH] jump indirect seems to be working as well

---
 src/asm.pest    |  2 +-
 src/asm.rs      |  1 +
 src/generate.rs |  6 ++++++
 src/parse.rs    |  5 +++++
 src/simulate.rs | 10 ++++++++++
 5 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/asm.pest b/src/asm.pest
index 00d8d99..bec746b 100644
--- a/src/asm.pest
+++ b/src/asm.pest
@@ -18,7 +18,7 @@ jump_instruction = {"JMP"}
 arg_instruction = {"LDA" | "ADD" | "SUB"}
 no_arg_instruction = { "NOP" }
 
-jump_argument = { jump_location | label }
+jump_argument = { jump_location | label | memory_location }
 argument = { memory_location | digit_literal }
 memory_location = { "(" ~ ASCII_HEX_DIGIT ~")" }
 digit_literal = {"#" ~ ASCII_HEX_DIGIT}
diff --git a/src/asm.rs b/src/asm.rs
index ecda5ce..91f9083 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -14,6 +14,7 @@ pub struct Label<'a> {
 pub enum JumpArgument<'a> {
     Location(u8),
     Label(&'a str),
+    MemoryLocation(u8),
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
diff --git a/src/generate.rs b/src/generate.rs
index cf74cd0..dd49e9f 100644
--- a/src/generate.rs
+++ b/src/generate.rs
@@ -68,6 +68,12 @@ pub fn generate_binary(instructions: Vec<Instruction>) -> Program {
                     } else {
                         panic!("Tried to JMP to label: {}, which does not exist", arg);
                     }
+                },
+                JumpArgument::MemoryLocation(address) => {
+                    BinaryInstruction {
+                        opcode: 12,
+                        argument: *address
+                    }
                 }
             },
         };
diff --git a/src/parse.rs b/src/parse.rs
index e9714fb..6fa4085 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -169,6 +169,11 @@ fn parse_jump_argument<'a>(arg: Pair<'a, Rule>) -> JumpArgument<'a> {
         Rule::label => JumpArgument::Label(arg.as_str()),
         Rule::jump_location => {
             JumpArgument::Location(u8::from_str_radix(arg.as_str(), 16).unwrap())
+        },
+        Rule::memory_location => {
+            let arg_string = arg.as_str();
+            let arg_value = u8::from_str_radix(&arg_string[1..arg_string.len() - 1], 16).unwrap();
+            JumpArgument::MemoryLocation(arg_value)
         }
         _ => unreachable!(),
     }
diff --git a/src/simulate.rs b/src/simulate.rs
index ad84688..a7a2400 100644
--- a/src/simulate.rs
+++ b/src/simulate.rs
@@ -138,6 +138,12 @@ pub fn simulate<'a>(instructions: Vec<Instruction<'a>>, max_steps: usize) -> Vec
                     } else {
                         panic!("Tried to JMP to label: {}, which does not exist", arg);
                     }
+                },
+                JumpArgument::MemoryLocation(address) => {
+                    BinaryInstruction {
+                        opcode: 12,
+                        argument: address
+                    }
                 }
             },
         };
@@ -205,6 +211,10 @@ pub fn simulate<'a>(instructions: Vec<Instruction<'a>>, max_steps: usize) -> Vec
                     next_pc = Some(location);
                     addr_bus = location;
                 },
+                JumpArgument::MemoryLocation(location) => {
+                    next_pc = Some(data_memory[location as usize]);
+                    addr_bus = data_memory[location as usize];
+                }
             },
             Instruction::MemoryLocationInstruction(arg, _) => match arg {
                 MemoryLocationInstruction::STA(arg) => {