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

chore: reimplement bus read/writes

Browse Source
This commit is contained in:
Rekai Nyangadzayi Musuka
2022-04-08 16:48:43 -03:00
parent 37a360ec07
commit 80e714e2eb
11 changed files with 130 additions and 166 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
src/cpu/thumb/data_transfer.zig
View File

@@ -11,7 +11,7 @@ pub fn format6(comptime rd: u3) InstrFn {
fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u16) void {
// LDR
const offset = (opcode & 0xFF) << 2;
cpu.r[rd] = bus.read32((cpu.r[15] + 2 & 0xFFFF_FFFD) + offset);
cpu.r[rd] = bus.read(u32, (cpu.r[15] + 2 & 0xFFFF_FFFD) + offset);
}
}.inner;
}
@@ -32,23 +32,23 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
switch (op) {
0b00 => {
// STRH
bus.write16(address, @truncate(u16, cpu.r[rd]));
bus.write(u16, address, @truncate(u16, cpu.r[rd]));
},
0b01 => {
// LDSB
cpu.r[rd] = sext(8, bus.read8(address));
cpu.r[rd] = sext(8, bus.read(u8, address));
},
0b10 => {
// LDRH
const value = bus.read16(address);
const value = bus.read(u16, address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
},
0b11 => {
// LDRSH
const value = if (address & 1 == 1) blk: {
break :blk sext(8, bus.read8(address));
break :blk sext(8, bus.read(u8, address));
} else blk: {
break :blk sext(16, bus.read16(address));
break :blk sext(16, bus.read(u16, address));
};
cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
@@ -59,20 +59,20 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
switch (op) {
0b00 => {
// STR
bus.write32(address, cpu.r[rd]);
bus.write(u32, address, cpu.r[rd]);
},
0b01 => {
// STRB
bus.write8(address, @truncate(u8, cpu.r[rd]));
bus.write(u8, address, @truncate(u8, cpu.r[rd]));
},
0b10 => {
// LDR
const value = bus.read32(address);
const value = bus.read(u32, address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
},
0b11 => {
// LDRB
cpu.r[rd] = bus.read8(address);
cpu.r[rd] = bus.read(u8, address);
},
}
}
@@ -90,22 +90,22 @@ pub fn format9(comptime B: bool, comptime L: bool, comptime offset: u5) InstrFn
if (B) {
// LDRB
const address = cpu.r[rb] + offset;
cpu.r[rd] = bus.read8(address);
cpu.r[rd] = bus.read(u8, address);
} else {
// LDR
const address = cpu.r[rb] + (@as(u32, offset) << 2);
const value = bus.read32(address);
const value = bus.read(u32, address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
}
} else {
if (B) {
// STRB
const address = cpu.r[rb] + offset;
bus.write8(address, @truncate(u8, cpu.r[rd]));
bus.write(u8, address, @truncate(u8, cpu.r[rd]));
} else {
// STR
const address = cpu.r[rb] + (@as(u32, offset) << 2);
bus.write32(address, cpu.r[rd]);
bus.write(u32, 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);
const value = bus.read(u16, address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
} else {
// STRH
bus.write16(address, @truncate(u16, cpu.r[rd]));
bus.write(u16, 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);
const value = bus.read(u32, address);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
} else {
// STR
bus.write32(address, cpu.r[rd]);
bus.write(u32, address, cpu.r[rd]);
}
}
}.inner;