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/*
Copyright 2021-2023 Gabriel Jensen.
This file is part of Luma.
Luma is free software: you can redistribute it
and/or modify it under the terms of the GNU
Affero General Public License as published by
the Free Software Foundation, either version 3
of the License, or (at your option) any later
version.
Luma is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU
Affero General Public License along with Luma.
If not, see <https://www.gnu.org/licenses/>.
*/
use crate::{Error, log};
use crate::cpu::{Cpu, take_state};
use crate::instruction::Instruction;
use crate::predicate::Predicate;
impl Cpu {
pub(super) fn fetch_thumb(&mut self) -> (Instruction, Predicate, u32) {
take_state!(state, self);
let address = state.read_register(0xF).wrapping_sub(0x4);
let opcode = state.read_halfword(address);
let cpsr = state.read_cpsr();
drop(state);
log!();
log!(" \u{1B}[1m{opcode:016b}\u{1B}[0m @ \u{1B}[1m{address:08X}\u{1B}[0m - ({})", self.cycle);
let (instruction, predicate) = Instruction::decode_thumb(opcode);
match (instruction, predicate) {
| (Instruction::Undefined, _)
| (_, Predicate::Nv)
=> Error::InvalidThumbOpcode(address, opcode).trap(),
_ => {},
};
return (instruction, predicate, cpsr);
}
}
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