natto1784/matar
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cpu: align PC every step

Browse Source 
Signed-off-by: Amneesh Singh <natto@weirdnatto.in>
This commit is contained in:
Amneesh Singh
2024-06-13 03:54:46 +05:30
parent 0029e302b2
commit c4a9c5ee5e
1 changed files with 6 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/cpu/cpu.cc
View File

@@ -1,6 +1,7 @@
#include "cpu/cpu.hh" #include "cpu/cpu.hh"
#include "cpu/arm/instruction.hh" #include "cpu/arm/instruction.hh"
#include "cpu/thumb/instruction.hh" #include "cpu/thumb/instruction.hh"
#include "util/bits.hh"
#include "util/log.hh" #include "util/log.hh"
#include <algorithm> #include <algorithm>
#include <cstdio> #include <cstdio>
@@ -131,8 +132,12 @@ Cpu::chg_mode(const Mode to) {
void void
Cpu::step() { Cpu::step() {
// Current instruction is two instructions behind PC // halfword align
rst_bit(pc, 0);
if (cpsr.state() == State::Arm) { if (cpsr.state() == State::Arm) {
// word align
rst_bit(pc, 1);
// Current instruction is two instructions behind PC
uint32_t cur_pc = pc - 2 * arm::INSTRUCTION_SIZE; uint32_t cur_pc = pc - 2 * arm::INSTRUCTION_SIZE;
arm::Instruction instruction(bus->read_word(cur_pc)); arm::Instruction instruction(bus->read_word(cur_pc));