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fix(cpu): force align thumb and arm block data transfers

This commit is contained in:
Rekai Nyangadzayi Musuka 2022-02-06 17:08:12 -04:00
parent 225c0f7d55
commit bbd4447734
2 changed files with 40 additions and 42 deletions
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18
src/cpu/arm/block_data_transfer.zig
View File

@ -48,17 +48,17 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
var address = start; var address = start;
if (rlist == 0) { if (rlist == 0) {
var pc_addr = cpu.r[rn]; var und_addr = cpu.r[rn];
if (U) { if (U) {
pc_addr += if (P) 4 else 0; und_addr += if (P) 4 else 0;
} else { } else {
pc_addr -= 0x40 - if (!P) 4 else 0; und_addr -= 0x40 - if (!P) 4 else 0;
} }
if (L) { if (L) {
cpu.r[15] = bus.read32(pc_addr); cpu.r[15] = bus.read32(und_addr & 0xFFFF_FFFC);
} else { } else {
bus.write32(pc_addr, cpu.r[15] + 8); bus.write32(und_addr & 0xFFFF_FFFC, cpu.r[15] + 8);
} }
cpu.r[rn] = if (U) cpu.r[rn] + 0x40 else cpu.r[rn] - 0x40; cpu.r[rn] = if (U) cpu.r[rn] + 0x40 else cpu.r[rn] - 0x40;
@ -85,9 +85,9 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
if (L) { if (L) {
if (S and !r15_present) { if (S and !r15_present) {
// Always Transfer User mode Registers // Always Transfer User mode Registers
cpu.setUserModeRegister(i, bus.read32(address)); cpu.setUserModeRegister(i, bus.read32(address & 0xFFFF_FFFC));
} else { } else {
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[i] = if (i == 0xF) value & 0xFFFF_FFFC else value; cpu.r[i] = if (i == 0xF) value & 0xFFFF_FFFC else value;
if (S and i == 0xF) cpu.setCpsr(cpu.spsr.raw); if (S and i == 0xF) cpu.setCpsr(cpu.spsr.raw);
} }
@ -96,9 +96,9 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
// Always Transfer User mode Registers // Always Transfer User mode Registers
// This happens regardless if r15 is in the list // This happens regardless if r15 is in the list
const value = cpu.getUserModeRegister(i); const value = cpu.getUserModeRegister(i);
bus.write32(address, value + if (i == 0xF) 8 else @as(u32, 0)); // PC is already 4 ahead to make 12 bus.write32(address & 0xFFFF_FFFC, value + if (i == 0xF) 8 else @as(u32, 0)); // PC is already 4 ahead to make 12
} else { } else {
bus.write32(address, cpu.r[i] + if (i == 0xF) 8 else @as(u32, 0)); bus.write32(address & 0xFFFF_FFFC, cpu.r[i] + if (i == 0xF) 8 else @as(u32, 0));
} }
} }
} }

60
src/cpu/thumb/block_data_transfer.zig
View File

@ -5,44 +5,42 @@ const InstrFn = @import("../../cpu.zig").ThumbInstrFn;
pub fn format14(comptime L: bool, comptime R: bool) InstrFn { pub fn format14(comptime L: bool, comptime R: bool) InstrFn {
return struct { return struct {
fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u16) void { fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u16) void {
var address: u32 = undefined; const count = countRlist(opcode);
const start = cpu.r[13] - if (!L) 4 * (@boolToInt(R) + count) else 0;
var end = cpu.r[13];
if (L) { if (L) {
// POP end += 4 * (@boolToInt(R) + count);
address = cpu.r[13]; } else {
end -= 4;
}
var address = start;
var i: u4 = 0; var i: u4 = 0;
while (i < 8) : (i += 1) { while (i < 8) : (i += 1) {
if ((opcode >> i) & 1 == 1) { if (opcode >> i & 1 == 1) {
cpu.r[i] = bus.read32(address); if (L) {
address += 4; cpu.r[i] = bus.read32(address & 0xFFFF_FFFC);
}
}
if (R) {
const value = bus.read32(address);
cpu.r[15] = value & 0xFFFF_FFFE;
address += 4;
}
} else { } else {
address = cpu.r[13] - 4; bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
if (R) {
bus.write32(address, cpu.r[14]);
address -= 4;
} }
var i: u4 = 8; address += 4;
while (i > 0) : (i -= 1) {
const j = i - 1;
if ((opcode >> j) & 1 == 1) {
bus.write32(address, cpu.r[j]);
address -= 4;
}
} }
} }
cpu.r[13] = address + if (!L) 4 else 0; if (R) {
if (L) {
const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[15] = value & 0xFFFF_FFFE;
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[14]);
}
address += 4;
}
cpu.r[13] = if (L) end else cpu.r[13] - 4 * (@boolToInt(R) + count);
} }
}.inner; }.inner;
} }
@ -54,7 +52,7 @@ pub fn format15(comptime L: bool, comptime rb: u3) InstrFn {
const end_address = cpu.r[rb] + 4 * countRlist(opcode); const end_address = cpu.r[rb] + 4 * countRlist(opcode);
if (opcode & 0xFF == 0) { if (opcode & 0xFF == 0) {
if (L) cpu.r[15] = bus.read32(address) else bus.write32(address, cpu.r[15] + 4); if (L) cpu.r[15] = bus.read32(address & 0xFFFF_FFFC) else bus.write32(address & 0xFFFF_FFFC, cpu.r[15] + 4);
cpu.r[rb] += 0x40; cpu.r[rb] += 0x40;
return; return;
} }
@ -65,9 +63,9 @@ pub fn format15(comptime L: bool, comptime rb: u3) InstrFn {
while (i < 8) : (i += 1) { while (i < 8) : (i += 1) {
if (opcode >> i & 1 == 1) { if (opcode >> i & 1 == 1) {
if (L) { if (L) {
cpu.r[i] = bus.read32(address); cpu.r[i] = bus.read32(address & 0xFFFF_FFFC);
} else { } else {
bus.write32(address, cpu.r[i]); bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
} }
if (!L and first_write) { if (!L and first_write) {