/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-23 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
/** @file Handling of low-level PPC exceptions. */
#include
#include "ppcemu.h"
#include "ppcmmu.h"
#include
#include
#include
jmp_buf exc_env; /* Global exception environment. */
void ppc_exception_handler(Except_Type exception_type, uint32_t srr1_bits) {
#ifdef CPU_PROFILING
exceptions_processed++;
#endif
switch (exception_type) {
case Except_Type::EXC_SYSTEM_RESET:
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0100;
break;
case Except_Type::EXC_MACHINE_CHECK:
if (!(ppc_state.msr & MSR::ME)) {
/* TODO: handle internal checkstop */
}
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0200;
break;
case Except_Type::EXC_DSI:
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0300;
break;
case Except_Type::EXC_ISI:
if (exec_flags) {
ppc_state.spr[SPR::SRR0] = ppc_next_instruction_address;
} else {
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFCUL;
}
ppc_next_instruction_address = 0x0400;
break;
case Except_Type::EXC_EXT_INT:
if (exec_flags) {
ppc_state.spr[SPR::SRR0] = ppc_next_instruction_address;
} else {
ppc_state.spr[SPR::SRR0] = (ppc_state.pc & 0xFFFFFFFCUL) + 4;
}
ppc_next_instruction_address = 0x0500;
break;
case Except_Type::EXC_ALIGNMENT:
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0600;
break;
case Except_Type::EXC_PROGRAM:
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0700;
break;
case Except_Type::EXC_NO_FPU:
ppc_state.spr[SPR::SRR0] = ppc_state.pc & 0xFFFFFFFC;
ppc_next_instruction_address = 0x0800;
break;
case Except_Type::EXC_DECR:
if (exec_flags) {
ppc_state.spr[SPR::SRR0] = ppc_next_instruction_address;
} else {
ppc_state.spr[SPR::SRR0] = (ppc_state.pc & 0xFFFFFFFCUL) + 4;
}
ppc_next_instruction_address = 0x0900;
break;
case Except_Type::EXC_SYSCALL:
ppc_state.spr[SPR::SRR0] = (ppc_state.pc & 0xFFFFFFFC) + 4;
ppc_next_instruction_address = 0x0C00;
break;
case Except_Type::EXC_TRACE:
ppc_state.spr[SPR::SRR0] = (ppc_state.pc & 0xFFFFFFFC) + 4;
ppc_next_instruction_address = 0x0D00;
break;
default:
ABORT_F("Unknown exception occurred: %X\n", (unsigned)exception_type);
break;
}
ppc_state.spr[SPR::SRR1] = (ppc_state.msr & 0x0000FF73) | srr1_bits;
ppc_state.msr &= 0xFFFB1041;
/* copy MSR[ILE] to MSR[LE] */
ppc_state.msr = (ppc_state.msr & ~MSR::LE) | !!(ppc_state.msr & MSR::ILE);
if (ppc_state.msr & MSR::IP) {
ppc_next_instruction_address |= 0xFFF00000;
}
exec_flags = EXEF_EXCEPTION;
// perform context synchronization for recoverable exceptions
if (exception_type != Except_Type::EXC_MACHINE_CHECK &&
exception_type != Except_Type::EXC_SYSTEM_RESET) {
do_ctx_sync();
}
mmu_change_mode();
if (exception_type != Except_Type::EXC_EXT_INT && exception_type != Except_Type::EXC_DECR) {
longjmp(exc_env, 2); /* return to the main execution loop. */
}
}
[[noreturn]] void dbg_exception_handler(Except_Type exception_type, uint32_t srr1_bits) {
std::string exc_descriptor;
switch (exception_type) {
case Except_Type::EXC_SYSTEM_RESET:
exc_descriptor = "System reset exception occurred";
break;
case Except_Type::EXC_MACHINE_CHECK:
exc_descriptor = "Machine check exception occurred";
break;
case Except_Type::EXC_DSI:
case Except_Type::EXC_ISI:
if (ppc_state.spr[SPR::DSISR] & 0x40000000)
exc_descriptor = "DSI/ISI exception: unmapped memory access";
else if (ppc_state.spr[SPR::DSISR] & 0x08000000)
exc_descriptor = "DSI/ISI exception: access protection violation";
else {
if (exception_type == Except_Type::EXC_DSI)
exc_descriptor = "DSI exception";
else
exc_descriptor = "ISI exception";
}
break;
case Except_Type::EXC_EXT_INT:
exc_descriptor = "External interrupt exception occurred";
break;
case Except_Type::EXC_ALIGNMENT:
exc_descriptor = "Alignment exception occurred";
break;
case Except_Type::EXC_PROGRAM:
exc_descriptor = "Program exception occurred";
break;
case Except_Type::EXC_NO_FPU:
exc_descriptor = "Floating-Point unavailable exception occurred";
break;
case Except_Type::EXC_DECR:
exc_descriptor = "Decrementer exception occurred";
break;
case Except_Type::EXC_SYSCALL:
exc_descriptor = "Syscall exception occurred";
break;
case Except_Type::EXC_TRACE:
exc_descriptor = "Trace exception occurred";
break;
}
throw std::invalid_argument(exc_descriptor);
}
void ppc_floating_point_exception() {
LOG_F(ERROR, "Floating point exception at 0x%08x for instruction 0x%08x",
ppc_state.pc, ppc_cur_instruction);
// mmu_exception_handler(Except_Type::EXC_PROGRAM, Exc_Cause::FPU_EXCEPTION);
}
void ppc_alignment_exception(uint32_t ea)
{
uint32_t dsisr;
switch (ppc_cur_instruction & 0xfc000000) {
case 0x80000000: // lwz
case 0x90000000: // stw
case 0xa0000000: // lhz
case 0xa8000000: // lha
case 0xb0000000: // sth
case 0xb8000000: // lmw
case 0xc0000000: // lfs
case 0xc8000000: // lfd
case 0xd0000000: // stfs
case 0xd8000000: // stfd
case 0x84000000: // lwzu
case 0x94000000: // stwu
case 0xa4000000: // lhzu
case 0xac000000: // lhau
case 0xb4000000: // sthu
case 0xbc000000: // stmw
case 0xc4000000: // lfsu
case 0xcc000000: // lfdu
case 0xd4000000: // stfsu
case 0xdc000000: // stfdu
indirect_with_immediate_index:
dsisr = ((ppc_cur_instruction >> 12) & 0x00004000) // bit 17 — Set to bit 5 of the instruction.
| ((ppc_cur_instruction >> 17) & 0x00003c00); // bits 18–21 - set to bits 1–4 of the instruction.
break;
case 0x7c000000:
switch (ppc_cur_instruction & 0xfc0007ff) {
case 0x7c000028: // lwarx (invalid form - bits 15-21 of DSISR are identical to those of lwz)
case 0x7c0002aa: // lwax (64-bit only)
case 0x7c00042a: // lswx
case 0x7c0004aa: // lswi
case 0x7c00052a: // stswx
case 0x7c0005aa: // stswi
case 0x7c0002ea: // lwaux (64 bit only)
case 0x7c00012c: // stwcx
case 0x7c00042c: // lwbrx
case 0x7c00052c: // stwbrx
case 0x7c00062c: // lhbrx
case 0x7c00072c: // sthbrx
case 0x7c00026c: // eciwx // MPC7451
case 0x7c00036c: // ecowx // MPC7451
case 0x7c00002e: // lwzx
case 0x7c00012e: // stwx
case 0x7c00022e: // lhzx
case 0x7c0002ae: // lhax
case 0x7c00032e: // sthx
case 0x7c00042e: // lfsx
case 0x7c0004ae: // lfdx
case 0x7c00052e: // stfsx
case 0x7c0005ae: // stfdx
case 0x7c00006e: // lwzux
case 0x7c00016e: // stwux
case 0x7c00026e: // lhzux
case 0x7c0002ee: // lhaux
case 0x7c00036e: // sthux
case 0x7c00046e: // lfsux
case 0x7c0004ee: // lfdux
case 0x7c00056e: // stfsux
case 0x7c0005ee: // stfdux
indirect_with_index:
dsisr = ((ppc_cur_instruction << 14) & 0x00018000) // bits 15–16 - set to bits 29–30 of the instruction.
| ((ppc_cur_instruction << 8) & 0x00004000) // bit 17 - set to bit 25 of the instruction.
| ((ppc_cur_instruction << 3) & 0x00003c00); // bits 18–21 - set to bits 21–24 of the instruction.
break;
case 0x7c0007ec:
if ((ppc_cur_instruction & 0xffe007ff) == 0x7c0007ec) // dcbz
goto indirect_with_index;
/* fallthrough */
default:
goto unexpected_instruction;
}
break;
default:
unexpected_instruction:
dsisr = 0;
LOG_F(ERROR, "Alignment exception from unexpected instruction 0x%08x",
ppc_cur_instruction);
}
// bits 22–26 - Set to bits 6–10 (source or destination) of the instruction.
// Undefined for dcbz.
dsisr |= ((ppc_cur_instruction >> 16) & 0x000003e0);
if ((ppc_cur_instruction & 0xfc000000) == 0xb8000000) { // lmw
LOG_F(ERROR, "Alignment exception from instruction 0x%08x (lmw). "
"What to set DSISR bits 27-31?", ppc_cur_instruction);
// dsisr |= ((ppc_cur_instruction >> ?) & 0x0000001f); // bits 27–31
}
else if ((ppc_cur_instruction & 0xfc0007ff) == 0x7c0004aa) { // lswi
LOG_F(ERROR, "Alignment exception from instruction 0x%08x (lswi). "
"What to set DSISR bits 27-31?", ppc_cur_instruction);
// dsisr |= ((ppc_cur_instruction >> ?) & 0x0000001f); // bits 27–31
}
else if ((ppc_cur_instruction & 0xfc0007ff) == 0x7c00042a) { // lswx
LOG_F(ERROR, "Alignment exception from instruction 0x%08x (lswx). "
"What to set DSISR bits 27-31?", ppc_cur_instruction);
// dsisr |= ((ppc_cur_instruction >> ?) & 0x0000001f); // bits 27–31
}
else {
// bits 27–31 - Set to bits 11–15 of the instruction (rA)
dsisr |= ((ppc_cur_instruction >> 16) & 0x0000001f);
}
ppc_state.spr[SPR::DSISR] = dsisr;
ppc_state.spr[SPR::DAR] = ea;
ppc_exception_handler(Except_Type::EXC_ALIGNMENT, 0x0);
}