arm: Implement MRS

Former-commit-id: 8c1528b2bcd08096f929c4ee940f1a1f5eac2911
This commit is contained in:
Michel Heily 2019-07-10 23:54:45 +03:00
parent 5f625b2209
commit 5bc4c79d6e

View file

@ -5,7 +5,7 @@ use crate::arm7tdmi::bus::Bus;
use crate::arm7tdmi::cpu::{Core, CpuExecResult, CpuPipelineAction};
use crate::arm7tdmi::exception::Exception;
use crate::arm7tdmi::psr::RegPSR;
use crate::arm7tdmi::{Addr, CpuError, CpuResult, CpuState, DecodedInstruction, REG_PC};
use crate::arm7tdmi::{Addr, CpuError, CpuMode, CpuResult, CpuState, DecodedInstruction, REG_PC};
use super::*;
@ -23,6 +23,7 @@ impl Core {
ArmFormat::LDR_STR_HS_IMM => self.exec_ldr_str_hs(bus, insn),
ArmFormat::LDR_STR_HS_REG => self.exec_ldr_str_hs(bus, insn),
ArmFormat::LDM_STM => self.exec_ldm_stm(bus, insn),
ArmFormat::MRS => self.exec_mrs(bus, insn),
ArmFormat::MSR_REG => self.exec_msr_reg(bus, insn),
ArmFormat::MSR_FLAGS => self.exec_msr_flags(bus, insn),
ArmFormat::MUL_MLA => self.exec_mul_mla(bus, insn),
@ -69,6 +70,21 @@ impl Core {
Ok(CpuPipelineAction::Flush)
}
fn exec_mrs(&mut self, _bus: &mut Bus, insn: ArmInstruction) -> CpuExecResult {
let mode = self.cpsr.mode();
let result = if insn.spsr_flag() {
if let Some(index) = mode.spsr_index() {
self.spsr[index].get()
} else {
panic!("tried to get spsr from invalid mode {}", mode)
}
} else {
self.cpsr.get()
};
self.set_reg(insn.rd(), result);
Ok(CpuPipelineAction::IncPC)
}
fn exec_msr_reg(&mut self, _bus: &mut Bus, insn: ArmInstruction) -> CpuExecResult {
self.exec_msr(insn, self.get_reg(insn.rm()))
}