paoda/zba
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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

Browse Source
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
Download Patch File Download Diff File Expand all files Collapse all files

12
src/cpu/arm/block_data_transfer.zig
View File

@@ -54,9 +54,9 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
}
if (L) {
cpu.r[15] = bus.read32(und_addr & 0xFFFF_FFFC);
cpu.r[15] = bus.read32(und_addr);
} else {
bus.write32(und_addr & 0xFFFF_FFFC, cpu.r[15] + 8);
bus.write32(und_addr, cpu.r[15] + 8);
}
cpu.r[rn] = if (U) cpu.r[rn] + 0x40 else cpu.r[rn] - 0x40;
@@ -83,9 +83,9 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
if (L) {
if (S and !r15_present) {
// Always Transfer User mode Registers
cpu.setUserModeRegister(i, bus.read32(address & 0xFFFF_FFFC));
cpu.setUserModeRegister(i, bus.read32(address));
} else {
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
cpu.r[i] = if (i == 0xF) value & 0xFFFF_FFFC else value;
if (S and i == 0xF) cpu.setCpsr(cpu.spsr.raw);
}
@@ -94,9 +94,9 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
// Always Transfer User mode Registers
// This happens regardless if r15 is in the list
const value = cpu.getUserModeRegister(i);
bus.write32(address & 0xFFFF_FFFC, value + if (i == 0xF) 8 else @as(u32, 0)); // PC is already 4 ahead to make 12
bus.write32(address, value + if (i == 0xF) 8 else @as(u32, 0)); // PC is already 4 ahead to make 12
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[i] + if (i == 0xF) 8 else @as(u32, 0));
bus.write32(address, cpu.r[i] + if (i == 0xF) 8 else @as(u32, 0));
}
}
}

4
src/cpu/arm/half_signed_data_transfer.zig
View File

@@ -38,7 +38,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
switch (@truncate(u2, opcode >> 5)) {
0b01 => {
// LDRH
const value = bus.read16(address & 0xFFFF_FFFE);
const value = bus.read16(address);
result = rotr(u32, value, 8 * (address & 1));
},
0b10 => {
@@ -60,7 +60,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
} else {
if (opcode >> 5 & 0x01 == 0x01) {
// STRH
bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
bus.write16(address, @truncate(u16, cpu.r[rd]));
} else unreachable; // SWP
}

4
src/cpu/arm/single_data_swap.zig
View File

@@ -22,8 +22,8 @@ pub fn singleDataSwap(comptime B: bool) InstrFn {
cpu.r[rd] = value;
} else {
// SWP
const value = rotr(u32, bus.read32(address & 0xFFFF_FFFC), 8 * (address & 0x3));
bus.write32(address & 0xFFFF_FFFC, cpu.r[rm]);
const value = rotr(u32, bus.read32(address), 8 * (address & 0x3));
bus.write32(address, cpu.r[rm]);
cpu.r[rd] = value;
}
}

4
src/cpu/arm/single_data_transfer.zig
View File

@@ -34,7 +34,7 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
result = bus.read8(address);
} else {
// LDR
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
result = rotr(u32, value, 8 * (address & 0x3));
}
} else {
@@ -45,7 +45,7 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
} else {
// STR
const value = if (rd == 0xF) cpu.r[rd] + 8 else cpu.r[rd];
bus.write32(address & 0xFFFF_FFFC, value);
bus.write32(address, value);
}
}

14
src/cpu/thumb/block_data_transfer.zig
View File

@@ -21,9 +21,9 @@ pub fn format14(comptime L: bool, comptime R: bool) InstrFn {
while (i < 8) : (i += 1) {
if (opcode >> i & 1 == 1) {
if (L) {
cpu.r[i] = bus.read32(address & 0xFFFF_FFFC);
cpu.r[i] = bus.read32(address);
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
bus.write32(address, cpu.r[i]);
}
address += 4;
@@ -32,10 +32,10 @@ pub fn format14(comptime L: bool, comptime R: bool) InstrFn {
if (R) {
if (L) {
const value = bus.read32(address & 0xFFFF_FFFC);
const value = bus.read32(address);
cpu.r[15] = value & 0xFFFF_FFFE;
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[14]);
bus.write32(address, cpu.r[14]);
}
address += 4;
}
@@ -52,7 +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 & 0xFFFF_FFFC) else bus.write32(address & 0xFFFF_FFFC, cpu.r[15] + 4);
if (L) cpu.r[15] = bus.read32(address) else bus.write32(address, cpu.r[15] + 4);
cpu.r[rb] += 0x40;
return;
}
@@ -63,9 +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 & 0xFFFF_FFFC);
cpu.r[i] = bus.read32(address);
} else {
bus.write32(address & 0xFFFF_FFFC, cpu.r[i]);
bus.write32(address, cpu.r[i]);
}
if (!L and first_write) {

20
src/cpu/thumb/data_transfer.zig
View File

@@ -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;