From e46697c9c757597c7abfb130fdf3973e3307f15e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Wed, 29 Jun 2022 10:43:01 +0100
Subject: [PATCH] feat: more opcodes
---
examples/sdl/src/main.rs | 4 ++--
src/cpu.rs | 21 ++++++++++++++++++---
2 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/examples/sdl/src/main.rs b/examples/sdl/src/main.rs
index bd1aa0c5..93bf270e 100644
--- a/examples/sdl/src/main.rs
+++ b/examples/sdl/src/main.rs
@@ -4,9 +4,9 @@ fn main() {
let mut game_boy = GameBoy::new();
game_boy.load_boot_default();
- for i in 0..24700 {
+ for i in 0..37000 {
game_boy.clock();
- if game_boy.cpu().pc() >= 0x3032 {
+ if game_boy.cpu().pc() >= 0x6032 {
println!("{}", i);
break;
}
diff --git a/src/cpu.rs b/src/cpu.rs
index 84ea6bdc..02f7d692 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -35,7 +35,7 @@ pub const INSTRUCTIONS: [(fn(&mut Cpu), u8, &'static str); 256] = [
(nop, 4, "! UNIMP !"),
(nop, 4, "! UNIMP !"),
(nop, 4, "! UNIMP !"),
- (nop, 4, "! UNIMP !"),
+ (ld_e_u8, 8, "LD E, u8"),
(nop, 4, "! UNIMP !"),
// 0x2 opcodes
(jr_nz_i8, 8, "JR NZ, i8"),
@@ -68,7 +68,7 @@ pub const INSTRUCTIONS: [(fn(&mut Cpu), u8, &'static str); 256] = [
(nop, 4, "! UNIMP !"),
(nop, 4, "! UNIMP !"),
(nop, 4, "! UNIMP !"),
- (nop, 4, "! UNIMP !"),
+ (dec_a, 4, "DEC A"),
(ld_a_u8, 8, "LD A, u8"),
(nop, 4, "! UNIMP !"),
// 0x4 opcodes
@@ -786,6 +786,11 @@ fn ld_a_mde(cpu: &mut Cpu) {
cpu.a = byte;
}
+fn ld_e_u8(cpu: &mut Cpu) {
+ let byte = cpu.read_u8();
+ cpu.e = byte;
+}
+
fn jr_nz_i8(cpu: &mut Cpu) {
let byte = cpu.read_u8() as i8;
@@ -820,6 +825,16 @@ fn ld_mhld_a(cpu: &mut Cpu) {
cpu.set_hl(cpu.hl().wrapping_sub(1));
}
+fn dec_a(cpu: &mut Cpu) {
+ let value = cpu.a.wrapping_sub(1);
+
+ cpu.set_sub(true);
+ cpu.set_zero(value == 0);
+ cpu.set_half_carry((value & 0xf) == 0xf);
+
+ cpu.a = value;
+}
+
fn ld_a_u8(cpu: &mut Cpu) {
let byte = cpu.read_u8();
cpu.a = byte;
@@ -934,7 +949,7 @@ fn sub_set_flags(cpu: &mut Cpu, x: u8, y: u8) -> u8 {
cpu.set_carry(value & 0x100 == 0x100);
cpu.set_zero(value_b == 0);
cpu.set_half_carry((x ^ y ^ value) & 0x10 == 0x10);
-
+
value_b
}
--
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