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fix: force align reads/writes in memory bus rather than in CPU

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This commit is contained in:
Rekai Nyangadzayi Musuka
2022-04-08 15:15:44 -03:00
parent a976a5769e
commit 37a360ec07
7 changed files with 108 additions and 104 deletions
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20
src/cpu/thumb/data_transfer.zig
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@@ -32,7 +32,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
switch (op) {
0b00 => {
// STRH
bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
bus.write16(address, @truncate(u16, cpu.r[rd]));
},
0b01 => {
// LDSB
@@ -40,7 +40,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
},
0b10 => {
// LDRH
const value = bus.read16(address & 0xFFFF_FFFE);
const value = bus.read16(address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
},
0b11 => {
@@ -59,7 +59,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
switch (op) {
0b00 => {
// STR
bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
bus.write32(address, cpu.r[rd]);
},
0b01 => {
// STRB
@@ -67,7 +67,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
},
0b10 => {
// LDR
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
},
0b11 => {
@@ -94,7 +94,7 @@ pub fn format9(comptime B: bool, comptime L: bool, comptime offset: u5) InstrFn
} else {
// LDR
const address = cpu.r[rb] + (@as(u32, offset) << 2);
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
}
} else {
@@ -105,7 +105,7 @@ pub fn format9(comptime B: bool, comptime L: bool, comptime offset: u5) InstrFn
} else {
// STR
const address = cpu.r[rb] + (@as(u32, offset) << 2);
bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
bus.write32(address, cpu.r[rd]);
}
}
}
@@ -122,11 +122,11 @@ pub fn format10(comptime L: bool, comptime offset: u5) InstrFn {
if (L) {
// LDRH
const value = bus.read16(address & 0xFFFF_FFFE);
const value = bus.read16(address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
} else {
// STRH
bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
bus.write16(address, @truncate(u16, cpu.r[rd]));
}
}
}.inner;
@@ -140,11 +140,11 @@ pub fn format11(comptime L: bool, comptime rd: u3) InstrFn {
if (L) {
// LDR
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
} else {
// STR
bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
bus.write32(address, cpu.r[rd]);
}
}
}.inner;