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base: paoda:37a360ec07c43ab61911809c4765d316168111e3
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paoda:main
paoda:april-fools
paoda:window
paoda:apu-things
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compare: paoda:6df55c2d86b6a2feaf7443c884fc563652159ae1
Branches Tags
paoda:main
paoda:april-fools
paoda:window
paoda:apu-things

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9 changed files with 101 additions and 124 deletions
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152
src/Bus.zig
View File

@ -14,9 +14,6 @@ const Scheduler = @import("scheduler.zig").Scheduler;
const io = @import("bus/io.zig"); const io = @import("bus/io.zig");
const Allocator = std.mem.Allocator; const Allocator = std.mem.Allocator;
const log = std.log.scoped(.Bus); const log = std.log.scoped(.Bus);
const rotr = @import("util.zig").rotr;
const Self = @This(); const Self = @This();
const panic_on_und_bus: bool = false; const panic_on_und_bus: bool = false;
@ -54,133 +51,120 @@ pub fn deinit(self: Self) void {
self.ppu.deinit(); self.ppu.deinit();
} }
pub fn read32(self: *const Self, address: u32) u32 { pub fn read32(self: *const Self, addr: u32) u32 {
const align_addr = address & 0xFFFF_FFFC; // Force Aligned return switch (addr) {
return switch (address) {
// General Internal Memory // General Internal Memory
0x0000_0000...0x0000_3FFF => self.bios.read(u32, align_addr), 0x0000_0000...0x0000_3FFF => self.bios.read(u32, addr),
0x0200_0000...0x02FF_FFFF => self.ewram.read(u32, align_addr), 0x0200_0000...0x02FF_FFFF => self.ewram.read(u32, addr),
0x0300_0000...0x03FF_FFFF => self.iwram.read(u32, align_addr), 0x0300_0000...0x03FF_FFFF => self.iwram.read(u32, addr),
0x0400_0000...0x0400_03FE => io.read32(self, align_addr), 0x0400_0000...0x0400_03FE => io.read32(self, addr),
// Internal Display Memory // Internal Display Memory
0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u32, align_addr), 0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u32, addr),
0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u32, align_addr), 0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u32, addr),
0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u32, align_addr), 0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u32, addr),
// External Memory (Game Pak) // External Memory (Game Pak)
0x0800_0000...0x09FF_FFFF => self.pak.read(u32, align_addr), 0x0800_0000...0x09FF_FFFF => self.pak.read(u32, addr),
0x0A00_0000...0x0BFF_FFFF => self.pak.read(u32, align_addr), 0x0A00_0000...0x0BFF_FFFF => self.pak.read(u32, addr),
0x0C00_0000...0x0DFF_FFFF => self.pak.read(u32, align_addr), 0x0C00_0000...0x0DFF_FFFF => self.pak.read(u32, addr),
0x0E00_0000...0x0FFF_FFFF => @as(u32, self.pak.backup.read(address)) * 0x01010101,
else => undRead("Tried to read from 0x{X:0>8}", .{address}), else => undRead("Tried to read from 0x{X:0>8}", .{addr}),
}; };
} }
pub fn write32(self: *Self, address: u32, word: u32) void { pub fn write32(self: *Self, addr: u32, word: u32) void {
const align_addr = address & 0xFFFF_FFFC; // Force Aligned // TODO: write32 can write to GamePak Flash
switch (address) { switch (addr) {
// General Internal Memory // General Internal Memory
0x0200_0000...0x02FF_FFFF => self.ewram.write(u32, align_addr, word), 0x0200_0000...0x02FF_FFFF => self.ewram.write(u32, addr, word),
0x0300_0000...0x03FF_FFFF => self.iwram.write(u32, align_addr, word), 0x0300_0000...0x03FF_FFFF => self.iwram.write(u32, addr, word),
0x0400_0000...0x0400_03FE => io.write32(self, align_addr, word), 0x0400_0000...0x0400_03FE => io.write32(self, addr, word),
// Internal Display Memory // Internal Display Memory
0x0500_0000...0x05FF_FFFF => self.ppu.palette.write(u32, align_addr, word), 0x0500_0000...0x05FF_FFFF => self.ppu.palette.write(u32, addr, word),
0x0600_0000...0x06FF_FFFF => self.ppu.vram.write(u32, align_addr, word), 0x0600_0000...0x06FF_FFFF => self.ppu.vram.write(u32, addr, word),
0x0700_0000...0x07FF_FFFF => self.ppu.oam.write(u32, align_addr, word), 0x0700_0000...0x07FF_FFFF => self.ppu.oam.write(u32, addr, word),
0x0E00_0000...0x0FFF_FFFF => self.pak.backup.write(address, @truncate(u8, rotr(u32, word, 8 * (address & 3)))),
else => undWrite("Tried to write 0x{X:0>8} to 0x{X:0>8}", .{ word, address }), else => undWrite("Tried to write 0x{X:0>8} to 0x{X:0>8}", .{ word, addr }),
} }
} }
pub fn read16(self: *const Self, address: u32) u16 { pub fn read16(self: *const Self, addr: u32) u16 {
const align_addr = address & 0xFFFF_FFFE; // Force Aligned return switch (addr) {
return switch (address) {
// General Internal Memory // General Internal Memory
0x0000_0000...0x0000_3FFF => self.bios.read(u16, align_addr), 0x0000_0000...0x0000_3FFF => self.bios.read(u16, addr),
0x0200_0000...0x02FF_FFFF => self.ewram.read(u16, align_addr), 0x0200_0000...0x02FF_FFFF => self.ewram.read(u16, addr),
0x0300_0000...0x03FF_FFFF => self.iwram.read(u16, align_addr), 0x0300_0000...0x03FF_FFFF => self.iwram.read(u16, addr),
0x0400_0000...0x0400_03FE => io.read16(self, align_addr), 0x0400_0000...0x0400_03FE => io.read16(self, addr),
// Internal Display Memory // Internal Display Memory
0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u16, align_addr), 0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u16, addr),
0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u16, align_addr), 0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u16, addr),
0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u16, align_addr), 0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u16, addr),
// External Memory (Game Pak) // External Memory (Game Pak)
0x0800_0000...0x09FF_FFFF => self.pak.read(u16, align_addr), 0x0800_0000...0x09FF_FFFF => self.pak.read(u16, addr),
0x0A00_0000...0x0BFF_FFFF => self.pak.read(u16, align_addr), 0x0A00_0000...0x0BFF_FFFF => self.pak.read(u16, addr),
0x0C00_0000...0x0DFF_FFFF => self.pak.read(u16, align_addr), 0x0C00_0000...0x0DFF_FFFF => self.pak.read(u16, addr),
0x0E00_0000...0x0FFF_FFFF => @as(u16, self.pak.backup.read(address)) * 0x0101,
else => undRead("Tried to read from 0x{X:0>8}", .{address}), else => undRead("Tried to read from 0x{X:0>8}", .{addr}),
}; };
} }
pub fn write16(self: *Self, address: u32, halfword: u16) void { pub fn write16(self: *Self, addr: u32, halfword: u16) void {
const align_addr = address & 0xFFFF_FFFE; // TODO: write16 can write to GamePak Flash
switch (addr) {
switch (address) {
// General Internal Memory // General Internal Memory
0x0200_0000...0x02FF_FFFF => self.ewram.write(u16, align_addr, halfword), 0x0200_0000...0x02FF_FFFF => self.ewram.write(u16, addr, halfword),
0x0300_0000...0x03FF_FFFF => self.iwram.write(u16, align_addr, halfword), 0x0300_0000...0x03FF_FFFF => self.iwram.write(u16, addr, halfword),
0x0400_0000...0x0400_03FE => io.write16(self, align_addr, halfword), 0x0400_0000...0x0400_03FE => io.write16(self, addr, halfword),
// Internal Display Memory // Internal Display Memory
0x0500_0000...0x05FF_FFFF => self.ppu.palette.write(u16, align_addr, halfword), 0x0500_0000...0x05FF_FFFF => self.ppu.palette.write(u16, addr, halfword),
0x0600_0000...0x06FF_FFFF => self.ppu.vram.write(u16, align_addr, halfword), 0x0600_0000...0x06FF_FFFF => self.ppu.vram.write(u16, addr, halfword),
0x0700_0000...0x07FF_FFFF => self.ppu.oam.write(u16, align_addr, halfword), 0x0700_0000...0x07FF_FFFF => self.ppu.oam.write(u16, addr, halfword),
0x0800_00C4, 0x0800_00C6, 0x0800_00C8 => log.warn("Tried to write 0x{X:0>4} to GPIO", .{halfword}), 0x0800_00C4, 0x0800_00C6, 0x0800_00C8 => log.warn("Tried to write 0x{X:0>4} to GPIO", .{halfword}),
// External Memory (Game Pak) else => undWrite("Tried to write 0x{X:0>4} to 0x{X:0>8}", .{ halfword, addr }),
0x0E00_0000...0x0FFF_FFFF => {
self.pak.backup.write(address, @truncate(u8, rotr(u16, halfword, 8 * (address & 1))));
},
else => undWrite("Tried to write 0x{X:0>4} to 0x{X:0>8}", .{ halfword, address }),
} }
} }
pub fn read8(self: *const Self, address: u32) u8 { pub fn read8(self: *const Self, addr: u32) u8 {
return switch (address) { return switch (addr) {
// General Internal Memory // General Internal Memory
0x0000_0000...0x0000_3FFF => self.bios.read(u8, address), 0x0000_0000...0x0000_3FFF => self.bios.read(u8, addr),
0x0200_0000...0x02FF_FFFF => self.ewram.read(u8, address), 0x0200_0000...0x02FF_FFFF => self.ewram.read(u8, addr),
0x0300_0000...0x03FF_FFFF => self.iwram.read(u8, address), 0x0300_0000...0x03FF_FFFF => self.iwram.read(u8, addr),
0x0400_0000...0x0400_03FE => io.read8(self, address), 0x0400_0000...0x0400_03FE => io.read8(self, addr),
// Internal Display Memory // Internal Display Memory
0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u8, address), 0x0500_0000...0x05FF_FFFF => self.ppu.palette.read(u8, addr),
0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u8, address), 0x0600_0000...0x06FF_FFFF => self.ppu.vram.read(u8, addr),
0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u8, address), 0x0700_0000...0x07FF_FFFF => self.ppu.oam.read(u8, addr),
// External Memory (Game Pak) // External Memory (Game Pak)
0x0800_0000...0x09FF_FFFF => self.pak.read(u8, address), 0x0800_0000...0x09FF_FFFF => self.pak.read(u8, addr),
0x0A00_0000...0x0BFF_FFFF => self.pak.read(u8, address), 0x0A00_0000...0x0BFF_FFFF => self.pak.read(u8, addr),
0x0C00_0000...0x0DFF_FFFF => self.pak.read(u8, address), 0x0C00_0000...0x0DFF_FFFF => self.pak.read(u8, addr),
0x0E00_0000...0x0FFF_FFFF => self.pak.backup.read(address), 0x0E00_0000...0x0E00_FFFF => self.pak.backup.read(addr),
else => undRead("Tried to read from 0x{X:0>2}", .{address}), else => undRead("Tried to read from 0x{X:0>2}", .{addr}),
}; };
} }
pub fn write8(self: *Self, address: u32, byte: u8) void { pub fn write8(self: *Self, addr: u32, byte: u8) void {
switch (address) { switch (addr) {
// General Internal Memory // General Internal Memory
0x0200_0000...0x02FF_FFFF => self.ewram.write(u8, address, byte), 0x0200_0000...0x02FF_FFFF => self.ewram.write(u8, addr, byte),
0x0300_0000...0x03FF_FFFF => self.iwram.write(u8, address, byte), 0x0300_0000...0x03FF_FFFF => self.iwram.write(u8, addr, byte),
0x0400_0000...0x0400_03FE => io.write8(self, address, byte), 0x0400_0000...0x0400_03FE => io.write8(self, addr, byte),
0x0400_0410 => log.info("Ignored write of 0x{X:0>2} to 0x{X:0>8}", .{ byte, address }), 0x0400_0410 => log.info("Ignored write of 0x{X:0>2} to 0x{X:0>8}", .{ byte, addr }),
// External Memory (Game Pak) // External Memory (Game Pak)
0x0E00_0000...0x0FFF_FFFF => self.pak.backup.write(address, byte), 0x0E00_0000...0x0E00_FFFF => self.pak.backup.write(addr, byte),
else => undWrite("Tried to write 0x{X:0>2} to 0x{X:0>8}", .{ byte, address }), else => undWrite("Tried to write 0x{X:0>2} to 0x{X:0>8}", .{ byte, addr }),
} }
} }

3
src/bus/GamePak.zig
View File

@ -21,7 +21,7 @@ pub fn init(alloc: Allocator, rom_path: []const u8, save_path: ?[]const u8) !Sel
defer alloc.free(file_buf); defer alloc.free(file_buf);
const title = parseTitle(file_buf); const title = parseTitle(file_buf);
const kind = Backup.guessKind(file_buf) orelse .None; const kind = Backup.guessKind(file_buf) orelse .Sram;
const buf = try alloc.alloc(u8, 0x200_0000); // 32MiB const buf = try alloc.alloc(u8, 0x200_0000); // 32MiB
@ -40,7 +40,6 @@ pub fn init(alloc: Allocator, rom_path: []const u8, save_path: ?[]const u8) !Sel
.backup = try Backup.init(alloc, kind, title, save_path), .backup = try Backup.init(alloc, kind, title, save_path),
}; };
pak.parseHeader(); pak.parseHeader();
log.info("Backup: {}", .{kind});
return pak; return pak;
} }

12
src/bus/backup.zig
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@ -32,11 +32,10 @@ pub const Backup = struct {
.Flash => 0x10000, // 64K .Flash => 0x10000, // 64K
.Flash1M => 0x20000, // 128K .Flash1M => 0x20000, // 128K
.Eeprom => 0x2000, // FIXME: We assume 8K here .Eeprom => 0x2000, // FIXME: We assume 8K here
.None => 0,
}; };
const buf = try alloc.alloc(u8, buf_len); const buf = try alloc.alloc(u8, buf_len);
std.mem.set(u8, buf, 0xFF); std.mem.set(u8, buf, 0);
var backup = Self{ var backup = Self{
.buf = buf, .buf = buf,
@ -81,10 +80,8 @@ pub const Backup = struct {
switch (self.kind) { switch (self.kind) {
.Sram, .Flash, .Flash1M => { .Sram, .Flash, .Flash1M => {
if (self.buf.len == file_buf.len) { std.mem.copy(u8, self.buf, file_buf);
std.mem.copy(u8, self.buf, file_buf); log.info("Loaded Save from {s}", .{file_path});
log.info("Loaded Save from {s}", .{file_path});
}
}, },
else => return SaveError.UnsupportedBackupKind, else => return SaveError.UnsupportedBackupKind,
} }
@ -142,7 +139,6 @@ pub const Backup = struct {
}, },
.Eeprom => return self.buf[addr], .Eeprom => return self.buf[addr],
.Sram => return self.buf[addr & 0x7FFF], // 32K SRAM chip is mirrored .Sram => return self.buf[addr & 0x7FFF], // 32K SRAM chip is mirrored
.None => return 0xFF,
} }
} }
@ -175,7 +171,6 @@ pub const Backup = struct {
}, },
.Eeprom => self.buf[addr] = byte, .Eeprom => self.buf[addr] = byte,
.Sram => self.buf[addr & 0x7FFF] = byte, .Sram => self.buf[addr & 0x7FFF] = byte,
.None => {},
} }
} }
}; };
@ -185,7 +180,6 @@ const BackupKind = enum {
Sram, Sram,
Flash, Flash,
Flash1M, Flash1M,
None,
}; };
const Needle = struct { const Needle = struct {

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) { if (L) {
cpu.r[15] = bus.read32(und_addr); cpu.r[15] = bus.read32(und_addr & 0xFFFF_FFFC);
} else { } else {
bus.write32(und_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;
@ -83,9 +83,9 @@ 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);
} }
@ -94,9 +94,9 @@ 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));
} }
} }
} }

4
src/cpu/arm/half_signed_data_transfer.zig
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@ -38,7 +38,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
switch (@truncate(u2, opcode >> 5)) { switch (@truncate(u2, opcode >> 5)) {
0b01 => { 0b01 => {
// LDRH // LDRH
const value = bus.read16(address); const value = bus.read16(address & 0xFFFF_FFFE);
result = rotr(u32, value, 8 * (address & 1)); result = rotr(u32, value, 8 * (address & 1));
}, },
0b10 => { 0b10 => {
@ -60,7 +60,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
} else { } else {
if (opcode >> 5 & 0x01 == 0x01) { if (opcode >> 5 & 0x01 == 0x01) {
// STRH // STRH
bus.write16(address, @truncate(u16, cpu.r[rd])); bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
} else unreachable; // SWP } 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; cpu.r[rd] = value;
} else { } else {
// SWP // SWP
const value = rotr(u32, bus.read32(address), 8 * (address & 0x3)); const value = rotr(u32, bus.read32(address & 0xFFFF_FFFC), 8 * (address & 0x3));
bus.write32(address, cpu.r[rm]); bus.write32(address & 0xFFFF_FFFC, cpu.r[rm]);
cpu.r[rd] = value; cpu.r[rd] = value;
} }
} }

4
src/cpu/arm/single_data_transfer.zig
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@ -34,7 +34,7 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
result = bus.read8(address); result = bus.read8(address);
} else { } else {
// LDR // LDR
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
result = rotr(u32, value, 8 * (address & 0x3)); result = rotr(u32, value, 8 * (address & 0x3));
} }
} else { } else {
@ -45,7 +45,7 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
} else { } else {
// STR // STR
const value = if (rd == 0xF) cpu.r[rd] + 8 else cpu.r[rd]; const value = if (rd == 0xF) cpu.r[rd] + 8 else cpu.r[rd];
bus.write32(address, value); bus.write32(address & 0xFFFF_FFFC, 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) { 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]);
} }
address += 4; address += 4;
@ -32,10 +32,10 @@ pub fn format14(comptime L: bool, comptime R: bool) InstrFn {
if (R) { if (R) {
if (L) { if (L) {
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[15] = value & 0xFFFF_FFFE; cpu.r[15] = value & 0xFFFF_FFFE;
} else { } else {
bus.write32(address, cpu.r[14]); bus.write32(address & 0xFFFF_FFFC, cpu.r[14]);
} }
address += 4; 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); 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;
} }
@ -63,9 +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) {

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) { switch (op) {
0b00 => { 0b00 => {
// STRH // STRH
bus.write16(address, @truncate(u16, cpu.r[rd])); bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
}, },
0b01 => { 0b01 => {
// LDSB // LDSB
@ -40,7 +40,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
}, },
0b10 => { 0b10 => {
// LDRH // LDRH
const value = bus.read16(address); const value = bus.read16(address & 0xFFFF_FFFE);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1)); cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
}, },
0b11 => { 0b11 => {
@ -59,7 +59,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
switch (op) { switch (op) {
0b00 => { 0b00 => {
// STR // STR
bus.write32(address, cpu.r[rd]); bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
}, },
0b01 => { 0b01 => {
// STRB // STRB
@ -67,7 +67,7 @@ pub fn format78(comptime op: u2, comptime T: bool) InstrFn {
}, },
0b10 => { 0b10 => {
// LDR // LDR
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3)); cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
}, },
0b11 => { 0b11 => {
@ -94,7 +94,7 @@ pub fn format9(comptime B: bool, comptime L: bool, comptime offset: u5) InstrFn
} else { } else {
// LDR // LDR
const address = cpu.r[rb] + (@as(u32, offset) << 2); const address = cpu.r[rb] + (@as(u32, offset) << 2);
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3)); cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
} }
} else { } else {
@ -105,7 +105,7 @@ pub fn format9(comptime B: bool, comptime L: bool, comptime offset: u5) InstrFn
} else { } else {
// STR // STR
const address = cpu.r[rb] + (@as(u32, offset) << 2); const address = cpu.r[rb] + (@as(u32, offset) << 2);
bus.write32(address, cpu.r[rd]); bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
} }
} }
} }
@ -122,11 +122,11 @@ pub fn format10(comptime L: bool, comptime offset: u5) InstrFn {
if (L) { if (L) {
// LDRH // LDRH
const value = bus.read16(address); const value = bus.read16(address & 0xFFFF_FFFE);
cpu.r[rd] = rotr(u32, value, 8 * (address & 1)); cpu.r[rd] = rotr(u32, value, 8 * (address & 1));
} else { } else {
// STRH // STRH
bus.write16(address, @truncate(u16, cpu.r[rd])); bus.write16(address & 0xFFFF_FFFE, @truncate(u16, cpu.r[rd]));
} }
} }
}.inner; }.inner;
@ -140,11 +140,11 @@ pub fn format11(comptime L: bool, comptime rd: u3) InstrFn {
if (L) { if (L) {
// LDR // LDR
const value = bus.read32(address); const value = bus.read32(address & 0xFFFF_FFFC);
cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3)); cpu.r[rd] = rotr(u32, value, 8 * (address & 0x3));
} else { } else {
// STR // STR
bus.write32(address, cpu.r[rd]); bus.write32(address & 0xFFFF_FFFC, cpu.r[rd]);
} }
} }
}.inner; }.inner;