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

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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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64
src/cpu/thumb/block_data_transfer.zig
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@@ -5,44 +5,42 @@ const InstrFn = @import("../../cpu.zig").ThumbInstrFn;
pub fn format14(comptime L: bool, comptime R: bool) InstrFn {
return struct {
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) {
// POP
address = cpu.r[13];
var i: u4 = 0;
while (i < 8) : (i += 1) {
if ((opcode >> i) & 1 == 1) {
cpu.r[i] = bus.read32(address);
address += 4;
}
}
if (R) {
const value = bus.read32(address);
cpu.r[15] = value & 0xFFFF_FFFE;
address += 4;
}
end += 4 * (@boolToInt(R) + count);
} else {
address = cpu.r[13] - 4;
end -= 4;
}
if (R) {
bus.write32(address, cpu.r[14]);
address -= 4;
}
var address = start;
var i: u4 = 8;
while (i > 0) : (i -= 1) {
const j = i - 1;
if ((opcode >> j) & 1 == 1) {
bus.write32(address, cpu.r[j]);
address -= 4;
var i: u4 = 0;
while (i < 8) : (i += 1) {
if (opcode >> i & 1 == 1) {
if (L) {
cpu.r[i] = bus.read32(address & 0xFFFF_FFFC);
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
}
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;
}
@@ -54,7 +52,7 @@ pub fn format15(comptime L: bool, comptime rb: u3) InstrFn {
const end_address = cpu.r[rb] + 4 * countRlist(opcode);
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;
return;
}
@@ -65,9 +63,9 @@ pub fn format15(comptime L: bool, comptime rb: u3) InstrFn {
while (i < 8) : (i += 1) {
if (opcode >> i & 1 == 1) {
if (L) {
cpu.r[i] = bus.read32(address);
cpu.r[i] = bus.read32(address & 0xFFFF_FFFC);
} else {
bus.write32(address, cpu.r[i]);
bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
}
if (!L and first_write) {