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ld_immediate_word

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Alex Janka 2023-01-16 11:46:00 +11:00
parent 289acd0070
commit ba69b1070b
1 changed files with 15 additions and 12 deletions
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27
src/main.rs
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@ -116,23 +116,18 @@ struct CPU {
impl CPU { impl CPU {
fn exec_next(&mut self) -> u8 { fn exec_next(&mut self) -> u8 {
let opcode = self.next_opcode(); let opcode = self.next_opcode();
println!("opcode: {:#X}", opcode);
match opcode { match opcode {
0x0 => { 0x0 => {
// noop // noop
} }
0x01 => { 0x01 => {
self.state.bc.as_u8s.left = self.next_opcode(); self.state.bc = self.ld_immediate_word();
self.state.bc.as_u8s.right = self.next_opcode();
} }
0x11 => { 0x11 => {
self.state.de.as_u8s.left = self.next_opcode(); self.state.de = self.ld_immediate_word();
self.state.de.as_u8s.right = self.next_opcode();
} }
0x21 => { 0x21 => {
self.state.de.as_u8s.left = self.next_opcode(); self.state.hl = self.ld_immediate_word();
self.state.de.as_u8s.right = self.next_opcode();
} }
0x2C => { 0x2C => {
unsafe { unsafe {
@ -145,9 +140,7 @@ impl CPU {
}; };
} }
0xC3 => { 0xC3 => {
let (a, b) = (self.next_opcode(), self.next_opcode()); self.state.pc = self.ld_immediate_word();
self.state.pc.as_u8s.left = a;
self.state.pc.as_u8s.right = b;
} }
_ => { _ => {
panic!("unimplemented opcode: {:#X}", opcode); panic!("unimplemented opcode: {:#X}", opcode);
@ -155,6 +148,7 @@ impl CPU {
}; };
return opcode; return opcode;
} }
fn next_opcode(&mut self) -> u8 { fn next_opcode(&mut self) -> u8 {
unsafe { unsafe {
let opcode = self.memory.get(self.state.pc.as_u16); let opcode = self.memory.get(self.state.pc.as_u16);
@ -162,6 +156,15 @@ impl CPU {
return opcode; return opcode;
}; };
} }
fn ld_immediate_word(&mut self) -> Register {
Register {
as_u8s: Inner {
left: self.next_opcode(),
right: self.next_opcode(),
},
}
}
} }
fn main() { fn main() {
@ -175,10 +178,10 @@ fn main() {
}; };
loop { loop {
cpu.exec_next(); cpu.exec_next();
pause();
} }
} }
#[allow(dead_code)]
fn pause() { fn pause() {
io::stdin().read_line(&mut String::new()).unwrap(); io::stdin().read_line(&mut String::new()).unwrap();
} }