Merge pull request 'Draft: Implement Instruction Pipeline' (#3) from pipeline into main
Reviewed-on: #3
This commit is contained in:
commit
f38c840d32
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@ -2,13 +2,13 @@
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An in-progress Game Boy Advance Emulator written in Zig ⚡!
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## Tests
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- [ ] [jsmolka's GBA Test Collection](https://github.com/jsmolka/gba-tests)
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- [x] [jsmolka's GBA Test Collection](https://github.com/jsmolka/gba-tests)
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- [x] `arm.gba` and `thumb.gba`
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- [x] `flash64.gba`, `flash128.gba`, `none.gba`, and `sram.gba`
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- [x] `hello.gba`, `shades.gba`, and `stripes.gba`
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- [x] `memory.gba`
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- [x] `bios.gba`
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- [ ] `nes.gba`
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- [x] `nes.gba`
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- [ ] [DenSinH's GBA ROMs](https://github.com/DenSinH/GBARoms)
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- [x] `eeprom-test` and `flash-test`
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- [x] `midikey2freq`
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@ -46,7 +46,7 @@ iwram: Iwram,
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ewram: Ewram,
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io: Io,
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cpu: ?*Arm7tdmi,
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cpu: *Arm7tdmi,
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sched: *Scheduler,
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pub fn init(self: *Self, allocator: Allocator, sched: *Scheduler, cpu: *Arm7tdmi, paths: FilePaths) !void {
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@ -82,9 +82,9 @@ pub fn dbgRead(self: *const Self, comptime T: type, address: u32) T {
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// General Internal Memory
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0x00 => blk: {
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if (address < Bios.size)
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break :blk self.bios.dbgRead(T, self.cpu.?.r[15], aligned_addr);
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break :blk self.bios.dbgRead(T, self.cpu.r[15], aligned_addr);
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break :blk self.readOpenBus(T, address);
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break :blk self.openBus(T, address);
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},
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0x02 => self.ewram.read(T, aligned_addr),
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0x03 => self.iwram.read(T, aligned_addr),
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@ -109,48 +109,63 @@ pub fn dbgRead(self: *const Self, comptime T: type, address: u32) T {
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break :blk @as(T, value) * multiplier;
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},
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else => self.readOpenBus(T, address),
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else => self.openBus(T, address),
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};
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}
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fn readIo(self: *const Self, comptime T: type, unaligned_address: u32) T {
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const maybe_value = io.read(self, T, forceAlign(T, unaligned_address));
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return if (maybe_value) |value| value else self.readOpenBus(T, unaligned_address);
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return if (maybe_value) |value| value else self.openBus(T, unaligned_address);
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}
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fn readOpenBus(self: *const Self, comptime T: type, address: u32) T {
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const r15 = self.cpu.?.r[15];
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fn openBus(self: *const Self, comptime T: type, address: u32) T {
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const r15 = self.cpu.r[15];
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const word = blk: {
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// If u32 Open Bus, read recently fetched opcode (PC + 8)
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if (!self.cpu.?.cpsr.t.read()) break :blk self.dbgRead(u32, r15 + 4);
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// If Arm, get the most recently fetched instruction (PC + 8)
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if (!self.cpu.cpsr.t.read()) break :blk self.cpu.pipe.stage[1].?;
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const page = @truncate(u8, r15 >> 24);
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// PC + 2 = stage[0]
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// PC + 4 = stage[1]
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// PC + 6 = Need a Debug Read for this?
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switch (page) {
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// EWRAM, PALRAM, VRAM, and Game ROM (16-bit)
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0x02, 0x05, 0x06, 0x08...0x0D => {
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// (PC + 4)
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const halfword = self.dbgRead(u16, r15 + 2);
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break :blk @as(u32, halfword) << 16 | halfword;
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const halfword: u32 = @truncate(u16, self.cpu.pipe.stage[1].?);
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break :blk halfword << 16 | halfword;
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},
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// BIOS or OAM (32-bit)
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0x00, 0x07 => {
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// Aligned: (PC + 6) | (PC + 4)
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// Unaligned: (PC + 4) | (PC + 2)
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const offset: u32 = if (address & 3 == 0b00) 2 else 0;
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const aligned = address & 3 == 0b00;
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break :blk @as(u32, self.dbgRead(u16, r15 + 2 + offset)) << 16 | self.dbgRead(u16, r15 + offset);
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// TODO: What to do on PC + 6?
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const high: u32 = if (aligned) self.dbgRead(u16, r15 + 4) else @truncate(u16, self.cpu.pipe.stage[1].?);
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const low: u32 = @truncate(u16, self.cpu.pipe.stage[@boolToInt(aligned)].?);
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break :blk high << 16 | low;
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},
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// IWRAM (16-bit but special)
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0x03 => {
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// Aligned: (PC + 2) | (PC + 4)
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// Unaligned: (PC + 4) | (PC + 2)
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const offset: u32 = if (address & 3 == 0b00) 2 else 0;
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const aligned = address & 3 == 0b00;
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break :blk @as(u32, self.dbgRead(u16, r15 + 2 - offset)) << 16 | self.dbgRead(u16, r15 + offset);
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const high: u32 = @truncate(u16, self.cpu.pipe.stage[1 - @boolToInt(aligned)].?);
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const low: u32 = @truncate(u16, self.cpu.pipe.stage[@boolToInt(aligned)].?);
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break :blk high << 16 | low;
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},
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else => {
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log.err("THUMB open bus read from 0x{X:0>2} page @0x{X:0>8}", .{ page, address });
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@panic("invariant most-likely broken");
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},
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else => unreachable,
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}
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};
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@ -167,9 +182,9 @@ pub fn read(self: *Self, comptime T: type, address: u32) T {
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// General Internal Memory
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0x00 => blk: {
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if (address < Bios.size)
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break :blk self.bios.read(T, self.cpu.?.r[15], aligned_addr);
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break :blk self.bios.read(T, self.cpu.r[15], aligned_addr);
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break :blk self.readOpenBus(T, address);
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break :blk self.openBus(T, address);
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},
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0x02 => self.ewram.read(T, aligned_addr),
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0x03 => self.iwram.read(T, aligned_addr),
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@ -194,7 +209,7 @@ pub fn read(self: *Self, comptime T: type, address: u32) T {
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break :blk @as(T, value) * multiplier;
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},
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else => self.readOpenBus(T, address),
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else => self.openBus(T, address),
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};
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}
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126
src/core/cpu.zig
126
src/core/cpu.zig
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@ -242,6 +242,7 @@ pub const Arm7tdmi = struct {
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const Self = @This();
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r: [16]u32,
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pipe: Pipeline,
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sched: *Scheduler,
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bus: *Bus,
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cpsr: PSR,
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@ -262,6 +263,7 @@ pub const Arm7tdmi = struct {
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pub fn init(sched: *Scheduler, bus: *Bus, log_file: ?std.fs.File) Self {
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return Self{
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.r = [_]u32{0x00} ** 16,
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.pipe = Pipeline.init(),
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.sched = sched,
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.bus = bus,
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.cpsr = .{ .raw = 0x0000_001F },
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@ -410,28 +412,42 @@ pub const Arm7tdmi = struct {
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self.cpsr.mode.write(@enumToInt(next));
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}
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/// Advances state so that the BIOS is skipped
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///
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/// Note: This accesses the CPU's bus ptr so it only may be called
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/// once the Bus has been properly initialized
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///
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/// TODO: Make above notice impossible to do in code
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pub fn fastBoot(self: *Self) void {
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self.r = std.mem.zeroes([16]u32);
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self.r[0] = 0x08000000;
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self.r[1] = 0x000000EA;
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// self.r[0] = 0x08000000;
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// self.r[1] = 0x000000EA;
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self.r[13] = 0x0300_7F00;
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self.r[15] = 0x0800_0000;
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self.banked_r[bankedIdx(.Irq, .R13)] = 0x0300_7FA0;
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self.banked_r[bankedIdx(.Supervisor, .R13)] = 0x0300_7FE0;
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self.cpsr.raw = 0x6000001F;
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// self.cpsr.raw = 0x6000001F;
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self.cpsr.raw = 0x0000_001F;
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self.bus.bios.addr_latch = 0x0000_00DC + 8;
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}
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pub fn step(self: *Self) void {
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defer {
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if (!self.pipe.flushed) self.r[15] += if (self.cpsr.t.read()) 2 else @as(u32, 4);
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self.pipe.flushed = false;
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}
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if (self.cpsr.t.read()) {
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const opcode = self.fetch(u16);
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const opcode = @truncate(u16, self.pipe.step(self, u16) orelse return);
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if (self.logger) |*trace| trace.mgbaLog(self, opcode);
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thumb.lut[thumb.idx(opcode)](self, self.bus, opcode);
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} else {
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const opcode = self.fetch(u32);
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const opcode = self.pipe.step(self, u32) orelse return;
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if (self.logger) |*trace| trace.mgbaLog(self, opcode);
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if (checkCond(self.cpsr, @truncate(u4, opcode >> 28))) {
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@ -472,42 +488,41 @@ pub const Arm7tdmi = struct {
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pub fn handleInterrupt(self: *Self) void {
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const should_handle = self.bus.io.ie.raw & self.bus.io.irq.raw;
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if (should_handle != 0) {
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self.bus.io.haltcnt = .Execute;
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// log.debug("An Interrupt was Fired!", .{});
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// Return if IME is disabled, CPSR I is set or there is nothing to handle
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if (!self.bus.io.ime or self.cpsr.i.read() or should_handle == 0) return;
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// Either IME is not true or I in CPSR is true
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// Don't handle interrupts
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if (!self.bus.io.ime or self.cpsr.i.read()) return;
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// log.debug("An interrupt was Handled!", .{});
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// If Pipeline isn't full, we have a bug
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std.debug.assert(self.pipe.isFull());
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// retAddr.gba says r15 on it's own is off by -04h in both ARM and THUMB mode
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const r15 = self.r[15] + 4;
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const cpsr = self.cpsr.raw;
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// log.debug("Handling Interrupt!", .{});
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self.bus.io.haltcnt = .Execute;
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self.changeMode(.Irq);
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self.cpsr.t.write(false);
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self.cpsr.i.write(true);
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// FIXME: This seems weird, but retAddr.gba suggests I need to make these changes
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const ret_addr = self.r[15] - if (self.cpsr.t.read()) 0 else @as(u32, 4);
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const new_spsr = self.cpsr.raw;
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self.r[14] = r15;
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self.spsr.raw = cpsr;
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self.r[15] = 0x000_0018;
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}
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self.changeMode(.Irq);
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self.cpsr.t.write(false);
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self.cpsr.i.write(true);
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self.r[14] = ret_addr;
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self.spsr.raw = new_spsr;
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self.r[15] = 0x0000_0018;
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self.pipe.reload(self);
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}
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inline fn fetch(self: *Self, comptime T: type) T {
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inline fn fetch(self: *Self, comptime T: type, address: u32) T {
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comptime std.debug.assert(T == u32 or T == u16); // Opcode may be 32-bit (ARM) or 16-bit (THUMB)
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defer self.r[15] += if (T == u32) 4 else 2;
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// FIXME: You better hope this is optimized out
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// Bus.read will advance the scheduler. There are different timings for CPU fetches,
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// so we want to undo what Bus.read will apply. We can do this by caching the current tick
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// This is very dumb.
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//
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// FIXME: Please rework this
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const tick_cache = self.sched.tick;
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defer self.sched.tick = tick_cache + Bus.fetch_timings[@boolToInt(T == u32)][@truncate(u4, self.r[15] >> 24)];
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defer self.sched.tick = tick_cache + Bus.fetch_timings[@boolToInt(T == u32)][@truncate(u4, address >> 24)];
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return self.bus.read(T, self.r[15]);
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}
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pub fn fakePC(self: *const Self) u32 {
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return self.r[15] + 4;
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return self.bus.read(T, address);
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}
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pub fn panic(self: *const Self, comptime format: []const u8, args: anytype) noreturn {
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@ -524,6 +539,8 @@ pub const Arm7tdmi = struct {
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std.debug.print("spsr: 0x{X:0>8} ", .{self.spsr.raw});
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prettyPrintPsr(&self.spsr);
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std.debug.print("pipeline: {??X:0>8}\n", .{self.pipe.stage});
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if (self.cpsr.t.read()) {
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const opcode = self.bus.dbgRead(u16, self.r[15] - 4);
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const id = thumb.idx(opcode);
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@ -587,7 +604,7 @@ pub const Arm7tdmi = struct {
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const r12 = self.r[12];
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const r13 = self.r[13];
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const r14 = self.r[14];
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const r15 = self.r[15];
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const r15 = self.r[15] -| if (self.cpsr.t.read()) 2 else @as(u32, 4);
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const c_psr = self.cpsr.raw;
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@ -595,7 +612,7 @@ pub const Arm7tdmi = struct {
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if (self.cpsr.t.read()) {
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if (opcode >> 11 == 0x1E) {
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// Instruction 1 of a BL Opcode, print in ARM mode
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const other_half = self.bus.dbgRead(u16, self.r[15]);
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const other_half = self.bus.debugRead(u16, self.r[15] - 2);
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const bl_opcode = @as(u32, opcode) << 16 | other_half;
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log_str = try std.fmt.bufPrint(&buf, arm_fmt, .{ r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, c_psr, bl_opcode });
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@ -631,6 +648,49 @@ pub fn checkCond(cpsr: PSR, cond: u4) bool {
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};
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}
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const Pipeline = struct {
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const Self = @This();
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stage: [2]?u32,
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flushed: bool,
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fn init() Self {
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return .{
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.stage = [_]?u32{null} ** 2,
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.flushed = false,
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};
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}
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pub fn isFull(self: *const Self) bool {
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return self.stage[0] != null and self.stage[1] != null;
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}
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pub fn step(self: *Self, cpu: *Arm7tdmi, comptime T: type) ?u32 {
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comptime std.debug.assert(T == u32 or T == u16);
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// FIXME: https://github.com/ziglang/zig/issues/12642
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var opcode = self.stage[0];
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self.stage[0] = self.stage[1];
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self.stage[1] = cpu.fetch(T, cpu.r[15]);
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return opcode;
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}
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pub fn reload(self: *Self, cpu: *Arm7tdmi) void {
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if (cpu.cpsr.t.read()) {
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self.stage[0] = cpu.fetch(u16, cpu.r[15]);
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self.stage[1] = cpu.fetch(u16, cpu.r[15] + 2);
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cpu.r[15] += 4;
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} else {
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self.stage[0] = cpu.fetch(u32, cpu.r[15]);
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self.stage[1] = cpu.fetch(u32, cpu.r[15] + 4);
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cpu.r[15] += 8;
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}
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self.flushed = true;
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}
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};
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pub const PSR = extern union {
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mode: Bitfield(u32, 0, 5),
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t: Bit(u32, 5),
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|
|
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@ -55,8 +55,10 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
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if (L) {
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cpu.r[15] = bus.read(u32, und_addr);
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cpu.pipe.reload(cpu);
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} else {
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bus.write(u32, und_addr, cpu.r[15] + 8);
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// FIXME: Should r15 on write be +12 ahead?
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bus.write(u32, und_addr, cpu.r[15] + 4);
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}
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cpu.r[rn] = if (U) cpu.r[rn] + 0x40 else cpu.r[rn] - 0x40;
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@ -86,17 +88,23 @@ pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, c
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cpu.setUserModeRegister(i, bus.read(u32, address));
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} else {
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const value = bus.read(u32, address);
|
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cpu.r[i] = if (i == 0xF) value & 0xFFFF_FFFC else value;
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if (S and i == 0xF) cpu.setCpsr(cpu.spsr.raw);
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cpu.r[i] = value;
|
||||
if (i == 0xF) {
|
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cpu.r[i] &= ~@as(u32, 3); // Align r15
|
||||
cpu.pipe.reload(cpu);
|
||||
|
||||
if (S) cpu.setCpsr(cpu.spsr.raw);
|
||||
}
|
||||
}
|
||||
} else {
|
||||
if (S) {
|
||||
// Always Transfer User mode Registers
|
||||
// This happens regardless if r15 is in the list
|
||||
const value = cpu.getUserModeRegister(i);
|
||||
bus.write(u32, address, value + if (i == 0xF) 8 else @as(u32, 0)); // PC is already 4 ahead to make 12
|
||||
bus.write(u32, address, value + if (i == 0xF) 4 else @as(u32, 0)); // PC is already 8 ahead to make 12
|
||||
} else {
|
||||
bus.write(u32, address, cpu.r[i] + if (i == 0xF) 8 else @as(u32, 0));
|
||||
bus.write(u32, address, cpu.r[i] + if (i == 0xF) 4 else @as(u32, 0));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -9,14 +9,20 @@ const sext = @import("../../../util.zig").sext;
|
|||
pub fn branch(comptime L: bool) InstrFn {
|
||||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
|
||||
if (L) cpu.r[14] = cpu.r[15];
|
||||
cpu.r[15] = cpu.fakePC() +% (sext(u32, u24, opcode) << 2);
|
||||
if (L) cpu.r[14] = cpu.r[15] - 4;
|
||||
|
||||
cpu.r[15] +%= sext(u32, u24, opcode) << 2;
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
||||
pub fn branchAndExchange(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
|
||||
const rn = opcode & 0xF;
|
||||
cpu.cpsr.t.write(cpu.r[rn] & 1 == 1);
|
||||
cpu.r[15] = cpu.r[rn] & 0xFFFF_FFFE;
|
||||
|
||||
const thumb = cpu.r[rn] & 1 == 1;
|
||||
cpu.r[15] = cpu.r[rn] & if (thumb) ~@as(u32, 1) else ~@as(u32, 3);
|
||||
|
||||
cpu.cpsr.t.write(thumb);
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -2,10 +2,10 @@ const Bus = @import("../../Bus.zig");
|
|||
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
|
||||
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
|
||||
|
||||
const rotateRight = @import("../barrel_shifter.zig").rotateRight;
|
||||
const execute = @import("../barrel_shifter.zig").execute;
|
||||
const exec = @import("../barrel_shifter.zig").exec;
|
||||
const ror = @import("../barrel_shifter.zig").ror;
|
||||
|
||||
pub fn dataProcessing(comptime I: bool, comptime S: bool, comptime instrKind: u4) InstrFn {
|
||||
pub fn dataProcessing(comptime I: bool, comptime S: bool, comptime kind: u4) InstrFn {
|
||||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
|
||||
const rd = @truncate(u4, opcode >> 12 & 0xF);
|
||||
|
|
@ -13,269 +13,168 @@ pub fn dataProcessing(comptime I: bool, comptime S: bool, comptime instrKind: u4
|
|||
const old_carry = @boolToInt(cpu.cpsr.c.read());
|
||||
|
||||
// If certain conditions are met, PC is 12 ahead instead of 8
|
||||
// TODO: Why these conditions?
|
||||
if (!I and opcode >> 4 & 1 == 1) cpu.r[15] += 4;
|
||||
const op1 = cpu.r[rn];
|
||||
|
||||
const op1 = if (rn == 0xF) cpu.fakePC() else cpu.r[rn];
|
||||
|
||||
var op2: u32 = undefined;
|
||||
if (I) {
|
||||
const amount = @truncate(u8, (opcode >> 8 & 0xF) << 1);
|
||||
op2 = rotateRight(S, &cpu.cpsr, opcode & 0xFF, amount);
|
||||
} else {
|
||||
op2 = execute(S, cpu, opcode);
|
||||
}
|
||||
const amount = @truncate(u8, (opcode >> 8 & 0xF) << 1);
|
||||
const op2 = if (I) ror(S, &cpu.cpsr, opcode & 0xFF, amount) else exec(S, cpu, opcode);
|
||||
|
||||
// Undo special condition from above
|
||||
if (!I and opcode >> 4 & 1 == 1) cpu.r[15] -= 4;
|
||||
|
||||
switch (instrKind) {
|
||||
0x0 => {
|
||||
// AND
|
||||
const result = op1 & op2;
|
||||
cpu.r[rd] = result;
|
||||
setArmLogicOpFlags(S, cpu, rd, result);
|
||||
},
|
||||
0x1 => {
|
||||
// EOR
|
||||
const result = op1 ^ op2;
|
||||
cpu.r[rd] = result;
|
||||
setArmLogicOpFlags(S, cpu, rd, result);
|
||||
},
|
||||
0x2 => {
|
||||
// SUB
|
||||
cpu.r[rd] = armSub(S, cpu, rd, op1, op2);
|
||||
},
|
||||
0x3 => {
|
||||
// RSB
|
||||
cpu.r[rd] = armSub(S, cpu, rd, op2, op1);
|
||||
},
|
||||
0x4 => {
|
||||
// ADD
|
||||
cpu.r[rd] = armAdd(S, cpu, rd, op1, op2);
|
||||
},
|
||||
0x5 => {
|
||||
// ADC
|
||||
cpu.r[rd] = armAdc(S, cpu, rd, op1, op2, old_carry);
|
||||
},
|
||||
0x6 => {
|
||||
// SBC
|
||||
cpu.r[rd] = armSbc(S, cpu, rd, op1, op2, old_carry);
|
||||
},
|
||||
0x7 => {
|
||||
// RSC
|
||||
cpu.r[rd] = armSbc(S, cpu, rd, op2, op1, old_carry);
|
||||
},
|
||||
var result: u32 = undefined;
|
||||
var overflow: bool = undefined;
|
||||
|
||||
// Perform Data Processing Logic
|
||||
switch (kind) {
|
||||
0x0 => result = op1 & op2, // AND
|
||||
0x1 => result = op1 ^ op2, // EOR
|
||||
0x2 => result = op1 -% op2, // SUB
|
||||
0x3 => result = op2 -% op1, // RSB
|
||||
0x4 => result = add(&overflow, op1, op2), // ADD
|
||||
0x5 => result = adc(&overflow, op1, op2, old_carry), // ADC
|
||||
0x6 => result = sbc(op1, op2, old_carry), // SBC
|
||||
0x7 => result = sbc(op2, op1, old_carry), // RSC
|
||||
0x8 => {
|
||||
// TST
|
||||
if (rd == 0xF) {
|
||||
undefinedTestBehaviour(cpu);
|
||||
return;
|
||||
}
|
||||
if (rd == 0xF)
|
||||
return undefinedTestBehaviour(cpu);
|
||||
|
||||
const result = op1 & op2;
|
||||
setTestOpFlags(S, cpu, opcode, result);
|
||||
result = op1 & op2;
|
||||
},
|
||||
0x9 => {
|
||||
// TEQ
|
||||
if (rd == 0xF) {
|
||||
undefinedTestBehaviour(cpu);
|
||||
return;
|
||||
}
|
||||
if (rd == 0xF)
|
||||
return undefinedTestBehaviour(cpu);
|
||||
|
||||
const result = op1 ^ op2;
|
||||
setTestOpFlags(S, cpu, opcode, result);
|
||||
result = op1 ^ op2;
|
||||
},
|
||||
0xA => {
|
||||
// CMP
|
||||
if (rd == 0xF) {
|
||||
undefinedTestBehaviour(cpu);
|
||||
return;
|
||||
}
|
||||
if (rd == 0xF)
|
||||
return undefinedTestBehaviour(cpu);
|
||||
|
||||
cmp(cpu, op1, op2);
|
||||
result = op1 -% op2;
|
||||
},
|
||||
0xB => {
|
||||
// CMN
|
||||
if (rd == 0xF) {
|
||||
undefinedTestBehaviour(cpu);
|
||||
return;
|
||||
}
|
||||
if (rd == 0xF)
|
||||
return undefinedTestBehaviour(cpu);
|
||||
|
||||
cmn(cpu, op1, op2);
|
||||
overflow = @addWithOverflow(u32, op1, op2, &result);
|
||||
},
|
||||
0xC => {
|
||||
// ORR
|
||||
const result = op1 | op2;
|
||||
0xC => result = op1 | op2, // ORR
|
||||
0xD => result = op2, // MOV
|
||||
0xE => result = op1 & ~op2, // BIC
|
||||
0xF => result = ~op2, // MVN
|
||||
}
|
||||
|
||||
// Write to Destination Register
|
||||
switch (kind) {
|
||||
0x8, 0x9, 0xA, 0xB => {}, // Test Operations
|
||||
else => {
|
||||
cpu.r[rd] = result;
|
||||
setArmLogicOpFlags(S, cpu, rd, result);
|
||||
if (rd == 0xF) {
|
||||
if (S) cpu.setCpsr(cpu.spsr.raw);
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
},
|
||||
0xD => {
|
||||
// MOV
|
||||
cpu.r[rd] = op2;
|
||||
setArmLogicOpFlags(S, cpu, rd, op2);
|
||||
}
|
||||
|
||||
// Write Flags
|
||||
switch (kind) {
|
||||
0x0, 0x1, 0xC, 0xD, 0xE, 0xF => if (S and rd != 0xF) {
|
||||
// Logic Operation Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
// C set by Barrel Shifter, V is unaffected
|
||||
|
||||
},
|
||||
0xE => {
|
||||
// BIC
|
||||
const result = op1 & ~op2;
|
||||
cpu.r[rd] = result;
|
||||
setArmLogicOpFlags(S, cpu, rd, result);
|
||||
0x2, 0x3 => if (S and rd != 0xF) {
|
||||
// SUB, RSB Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
if (kind == 0x2) {
|
||||
// SUB specific
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
} else {
|
||||
// RSB Specific
|
||||
cpu.cpsr.c.write(op1 <= op2);
|
||||
cpu.cpsr.v.write(((op2 ^ result) & (~op1 ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
},
|
||||
0xF => {
|
||||
// MVN
|
||||
const result = ~op2;
|
||||
cpu.r[rd] = result;
|
||||
setArmLogicOpFlags(S, cpu, rd, result);
|
||||
0x4, 0x5 => if (S and rd != 0xF) {
|
||||
// ADD, ADC Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(overflow);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0x6, 0x7 => if (S and rd != 0xF) {
|
||||
// SBC, RSC Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
if (kind == 0x6) {
|
||||
// SBC specific
|
||||
const subtrahend = @as(u64, op2) -% old_carry +% 1;
|
||||
cpu.cpsr.c.write(subtrahend <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
} else {
|
||||
// RSC Specific
|
||||
const subtrahend = @as(u64, op1) -% old_carry +% 1;
|
||||
cpu.cpsr.c.write(subtrahend <= op2);
|
||||
cpu.cpsr.v.write(((op2 ^ result) & (~op1 ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
},
|
||||
0x8, 0x9, 0xA, 0xB => {
|
||||
// Test Operation Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
if (kind == 0xA) {
|
||||
// CMP specific
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
} else if (kind == 0xB) {
|
||||
// CMN specific
|
||||
cpu.cpsr.c.write(overflow);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (op2 ^ result)) >> 31 & 1 == 1);
|
||||
} else {
|
||||
// TST, TEQ specific
|
||||
// Barrel Shifter should always calc CPSR C in TST
|
||||
if (!S) _ = exec(true, cpu, opcode);
|
||||
}
|
||||
},
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
||||
fn armSbc(comptime S: bool, cpu: *Arm7tdmi, rd: u4, left: u32, right: u32, old_carry: u1) u32 {
|
||||
var result: u32 = undefined;
|
||||
if (S and rd == 0xF) {
|
||||
result = sbc(false, cpu, left, right, old_carry);
|
||||
cpu.setCpsr(cpu.spsr.raw);
|
||||
} else {
|
||||
result = sbc(S, cpu, left, right, old_carry);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
pub fn sbc(comptime S: bool, cpu: *Arm7tdmi, left: u32, right: u32, old_carry: u1) u32 {
|
||||
pub fn sbc(left: u32, right: u32, old_carry: u1) u32 {
|
||||
// TODO: Make your own version (thanks peach.bot)
|
||||
const subtrahend = @as(u64, right) -% old_carry +% 1;
|
||||
const result = @truncate(u32, left -% subtrahend);
|
||||
const ret = @truncate(u32, left -% subtrahend);
|
||||
|
||||
if (S) {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(subtrahend <= left);
|
||||
cpu.cpsr.v.write(((left ^ result) & (~right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
return result;
|
||||
return ret;
|
||||
}
|
||||
|
||||
fn armSub(comptime S: bool, cpu: *Arm7tdmi, rd: u4, left: u32, right: u32) u32 {
|
||||
var result: u32 = undefined;
|
||||
if (S and rd == 0xF) {
|
||||
result = sub(false, cpu, left, right);
|
||||
cpu.setCpsr(cpu.spsr.raw);
|
||||
} else {
|
||||
result = sub(S, cpu, left, right);
|
||||
}
|
||||
|
||||
return result;
|
||||
pub fn add(overflow: *bool, left: u32, right: u32) u32 {
|
||||
var ret: u32 = undefined;
|
||||
overflow.* = @addWithOverflow(u32, left, right, &ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
pub fn sub(comptime S: bool, cpu: *Arm7tdmi, left: u32, right: u32) u32 {
|
||||
const result = left -% right;
|
||||
pub fn adc(overflow: *bool, left: u32, right: u32, old_carry: u1) u32 {
|
||||
var ret: u32 = undefined;
|
||||
const first = @addWithOverflow(u32, left, right, &ret);
|
||||
const second = @addWithOverflow(u32, ret, old_carry, &ret);
|
||||
|
||||
if (S) {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(right <= left);
|
||||
cpu.cpsr.v.write(((left ^ result) & (~right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
fn armAdd(comptime S: bool, cpu: *Arm7tdmi, rd: u4, left: u32, right: u32) u32 {
|
||||
var result: u32 = undefined;
|
||||
if (S and rd == 0xF) {
|
||||
result = add(false, cpu, left, right);
|
||||
cpu.setCpsr(cpu.spsr.raw);
|
||||
} else {
|
||||
result = add(S, cpu, left, right);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
pub fn add(comptime S: bool, cpu: *Arm7tdmi, left: u32, right: u32) u32 {
|
||||
var result: u32 = undefined;
|
||||
const didOverflow = @addWithOverflow(u32, left, right, &result);
|
||||
|
||||
if (S) {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(didOverflow);
|
||||
cpu.cpsr.v.write(((left ^ result) & (right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
fn armAdc(comptime S: bool, cpu: *Arm7tdmi, rd: u4, left: u32, right: u32, old_carry: u1) u32 {
|
||||
var result: u32 = undefined;
|
||||
if (S and rd == 0xF) {
|
||||
result = adc(false, cpu, left, right, old_carry);
|
||||
cpu.setCpsr(cpu.spsr.raw);
|
||||
} else {
|
||||
result = adc(S, cpu, left, right, old_carry);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
pub fn adc(comptime S: bool, cpu: *Arm7tdmi, left: u32, right: u32, old_carry: u1) u32 {
|
||||
var result: u32 = undefined;
|
||||
const did = @addWithOverflow(u32, left, right, &result);
|
||||
const overflow = @addWithOverflow(u32, result, old_carry, &result);
|
||||
|
||||
if (S) {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(did or overflow);
|
||||
cpu.cpsr.v.write(((left ^ result) & (right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
pub fn cmp(cpu: *Arm7tdmi, left: u32, right: u32) void {
|
||||
const result = left -% right;
|
||||
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(right <= left);
|
||||
cpu.cpsr.v.write(((left ^ result) & (~right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
pub fn cmn(cpu: *Arm7tdmi, left: u32, right: u32) void {
|
||||
var result: u32 = undefined;
|
||||
const didOverflow = @addWithOverflow(u32, left, right, &result);
|
||||
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(didOverflow);
|
||||
cpu.cpsr.v.write(((left ^ result) & (right ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
|
||||
fn setArmLogicOpFlags(comptime S: bool, cpu: *Arm7tdmi, rd: u4, result: u32) void {
|
||||
if (S and rd == 0xF) {
|
||||
cpu.setCpsr(cpu.spsr.raw);
|
||||
} else {
|
||||
setLogicOpFlags(S, cpu, result);
|
||||
}
|
||||
}
|
||||
|
||||
pub fn setLogicOpFlags(comptime S: bool, cpu: *Arm7tdmi, result: u32) void {
|
||||
if (S) {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
// C set by Barrel Shifter, V is unaffected
|
||||
}
|
||||
}
|
||||
|
||||
fn setTestOpFlags(comptime S: bool, cpu: *Arm7tdmi, opcode: u32, result: u32) void {
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
// Barrel Shifter should always calc CPSR C in TST
|
||||
if (!S) _ = execute(true, cpu, opcode);
|
||||
overflow.* = first or second;
|
||||
return ret;
|
||||
}
|
||||
|
||||
fn undefinedTestBehaviour(cpu: *Arm7tdmi) void {
|
||||
|
|
|
|||
|
|
@ -15,20 +15,8 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
|
|||
const rm = opcode & 0xF;
|
||||
const imm_offset_high = opcode >> 8 & 0xF;
|
||||
|
||||
var base: u32 = undefined;
|
||||
if (rn == 0xF) {
|
||||
base = cpu.fakePC();
|
||||
if (!L) base += 4;
|
||||
} else {
|
||||
base = cpu.r[rn];
|
||||
}
|
||||
|
||||
var offset: u32 = undefined;
|
||||
if (I) {
|
||||
offset = imm_offset_high << 4 | rm;
|
||||
} else {
|
||||
offset = cpu.r[rm];
|
||||
}
|
||||
const base = cpu.r[rn] + if (!L and rn == 0xF) 4 else @as(u32, 0);
|
||||
const offset = if (I) imm_offset_high << 4 | rm else cpu.r[rm];
|
||||
|
||||
const modified_base = if (U) base +% offset else base -% offset;
|
||||
var address = if (P) modified_base else base;
|
||||
|
|
|
|||
|
|
@ -14,15 +14,10 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
|
|||
const rn = opcode >> 16 & 0xF;
|
||||
const rd = opcode >> 12 & 0xF;
|
||||
|
||||
var base: u32 = undefined;
|
||||
if (rn == 0xF) {
|
||||
base = cpu.fakePC();
|
||||
if (!L) base += 4; // Offset of 12
|
||||
} else {
|
||||
base = cpu.r[rn];
|
||||
}
|
||||
// rn is r15 and L is not set, the PC is 12 ahead
|
||||
const base = cpu.r[rn] + if (!L and rn == 0xF) 4 else @as(u32, 0);
|
||||
|
||||
const offset = if (I) shifter.immShift(false, cpu, opcode) else opcode & 0xFFF;
|
||||
const offset = if (I) shifter.immediate(false, cpu, opcode) else opcode & 0xFFF;
|
||||
|
||||
const modified_base = if (U) base +% offset else base -% offset;
|
||||
var address = if (P) modified_base else base;
|
||||
|
|
@ -40,18 +35,26 @@ pub fn singleDataTransfer(comptime I: bool, comptime P: bool, comptime U: bool,
|
|||
} else {
|
||||
if (B) {
|
||||
// STRB
|
||||
const value = if (rd == 0xF) cpu.r[rd] + 8 else cpu.r[rd];
|
||||
const value = cpu.r[rd] + if (rd == 0xF) 4 else @as(u32, 0); // PC is 12 ahead
|
||||
bus.write(u8, address, @truncate(u8, value));
|
||||
} else {
|
||||
// STR
|
||||
const value = if (rd == 0xF) cpu.r[rd] + 8 else cpu.r[rd];
|
||||
const value = cpu.r[rd] + if (rd == 0xF) 4 else @as(u32, 0);
|
||||
bus.write(u32, address, value);
|
||||
}
|
||||
}
|
||||
|
||||
address = modified_base;
|
||||
if (W and P or !P) cpu.r[rn] = address;
|
||||
if (L) cpu.r[rd] = result; // This emulates the LDR rd == rn behaviour
|
||||
if (W and P or !P) {
|
||||
cpu.r[rn] = address;
|
||||
if (rn == 0xF) cpu.pipe.reload(cpu);
|
||||
}
|
||||
|
||||
if (L) {
|
||||
// This emulates the LDR rd == rn behaviour
|
||||
cpu.r[rd] = result;
|
||||
if (rd == 0xF) cpu.pipe.reload(cpu);
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -6,7 +6,7 @@ pub fn armSoftwareInterrupt() InstrFn {
|
|||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, _: u32) void {
|
||||
// Copy Values from Current Mode
|
||||
const r15 = cpu.r[15];
|
||||
const ret_addr = cpu.r[15] - 4;
|
||||
const cpsr = cpu.cpsr.raw;
|
||||
|
||||
// Switch Mode
|
||||
|
|
@ -14,9 +14,10 @@ pub fn armSoftwareInterrupt() InstrFn {
|
|||
cpu.cpsr.t.write(false); // Force ARM Mode
|
||||
cpu.cpsr.i.write(true); // Disable normal interrupts
|
||||
|
||||
cpu.r[14] = r15; // Resume Execution
|
||||
cpu.r[14] = ret_addr; // Resume Execution
|
||||
cpu.spsr.raw = cpsr; // Previous mode CPSR
|
||||
cpu.r[15] = 0x0000_0008;
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,37 +5,33 @@ const CPSR = @import("../cpu.zig").PSR;
|
|||
|
||||
const rotr = @import("../../util.zig").rotr;
|
||||
|
||||
pub fn execute(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
pub fn exec(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
var result: u32 = undefined;
|
||||
if (opcode >> 4 & 1 == 1) {
|
||||
result = registerShift(S, cpu, opcode);
|
||||
result = register(S, cpu, opcode);
|
||||
} else {
|
||||
result = immShift(S, cpu, opcode);
|
||||
result = immediate(S, cpu, opcode);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
fn registerShift(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
fn register(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
const rs_idx = opcode >> 8 & 0xF;
|
||||
const rm = cpu.r[opcode & 0xF];
|
||||
const rs = @truncate(u8, cpu.r[rs_idx]);
|
||||
|
||||
const rm_idx = opcode & 0xF;
|
||||
const rm = if (rm_idx == 0xF) cpu.fakePC() else cpu.r[rm_idx];
|
||||
|
||||
return switch (@truncate(u2, opcode >> 5)) {
|
||||
0b00 => logicalLeft(S, &cpu.cpsr, rm, rs),
|
||||
0b01 => logicalRight(S, &cpu.cpsr, rm, rs),
|
||||
0b10 => arithmeticRight(S, &cpu.cpsr, rm, rs),
|
||||
0b11 => rotateRight(S, &cpu.cpsr, rm, rs),
|
||||
0b00 => lsl(S, &cpu.cpsr, rm, rs),
|
||||
0b01 => lsr(S, &cpu.cpsr, rm, rs),
|
||||
0b10 => asr(S, &cpu.cpsr, rm, rs),
|
||||
0b11 => ror(S, &cpu.cpsr, rm, rs),
|
||||
};
|
||||
}
|
||||
|
||||
pub fn immShift(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
pub fn immediate(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
||||
const amount = @truncate(u8, opcode >> 7 & 0x1F);
|
||||
|
||||
const rm_idx = opcode & 0xF;
|
||||
const rm = if (rm_idx == 0xF) cpu.fakePC() else cpu.r[rm_idx];
|
||||
const rm = cpu.r[opcode & 0xF];
|
||||
|
||||
var result: u32 = undefined;
|
||||
if (amount == 0) {
|
||||
|
|
@ -64,17 +60,17 @@ pub fn immShift(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
|
|||
}
|
||||
} else {
|
||||
switch (@truncate(u2, opcode >> 5)) {
|
||||
0b00 => result = logicalLeft(S, &cpu.cpsr, rm, amount),
|
||||
0b01 => result = logicalRight(S, &cpu.cpsr, rm, amount),
|
||||
0b10 => result = arithmeticRight(S, &cpu.cpsr, rm, amount),
|
||||
0b11 => result = rotateRight(S, &cpu.cpsr, rm, amount),
|
||||
0b00 => result = lsl(S, &cpu.cpsr, rm, amount),
|
||||
0b01 => result = lsr(S, &cpu.cpsr, rm, amount),
|
||||
0b10 => result = asr(S, &cpu.cpsr, rm, amount),
|
||||
0b11 => result = ror(S, &cpu.cpsr, rm, amount),
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
pub fn logicalLeft(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
pub fn lsl(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
const amount = @truncate(u5, total_amount);
|
||||
const bit_count: u8 = @typeInfo(u32).Int.bits;
|
||||
|
||||
|
|
@ -101,7 +97,7 @@ pub fn logicalLeft(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32
|
|||
return result;
|
||||
}
|
||||
|
||||
pub fn logicalRight(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u32) u32 {
|
||||
pub fn lsr(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u32) u32 {
|
||||
const amount = @truncate(u5, total_amount);
|
||||
const bit_count: u8 = @typeInfo(u32).Int.bits;
|
||||
|
||||
|
|
@ -125,7 +121,7 @@ pub fn logicalRight(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u32) u
|
|||
return result;
|
||||
}
|
||||
|
||||
pub fn arithmeticRight(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
pub fn asr(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
const amount = @truncate(u5, total_amount);
|
||||
const bit_count: u8 = @typeInfo(u32).Int.bits;
|
||||
|
||||
|
|
@ -142,7 +138,7 @@ pub fn arithmeticRight(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8)
|
|||
return result;
|
||||
}
|
||||
|
||||
pub fn rotateRight(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
pub fn ror(comptime S: bool, cpsr: *CPSR, rm: u32, total_amount: u8) u32 {
|
||||
const result = rotr(u32, rm, total_amount);
|
||||
|
||||
if (S and total_amount != 0) {
|
||||
|
|
|
|||
|
|
@ -4,16 +4,11 @@ const InstrFn = @import("../../cpu.zig").thumb.InstrFn;
|
|||
|
||||
const adc = @import("../arm/data_processing.zig").adc;
|
||||
const sbc = @import("../arm/data_processing.zig").sbc;
|
||||
const sub = @import("../arm/data_processing.zig").sub;
|
||||
const cmp = @import("../arm/data_processing.zig").cmp;
|
||||
const cmn = @import("../arm/data_processing.zig").cmn;
|
||||
const setTestOpFlags = @import("../arm/data_processing.zig").setTestOpFlags;
|
||||
const setLogicOpFlags = @import("../arm/data_processing.zig").setLogicOpFlags;
|
||||
|
||||
const logicalLeft = @import("../barrel_shifter.zig").logicalLeft;
|
||||
const logicalRight = @import("../barrel_shifter.zig").logicalRight;
|
||||
const arithmeticRight = @import("../barrel_shifter.zig").arithmeticRight;
|
||||
const rotateRight = @import("../barrel_shifter.zig").rotateRight;
|
||||
const lsl = @import("../barrel_shifter.zig").lsl;
|
||||
const lsr = @import("../barrel_shifter.zig").lsr;
|
||||
const asr = @import("../barrel_shifter.zig").asr;
|
||||
const ror = @import("../barrel_shifter.zig").ror;
|
||||
|
||||
pub fn fmt4(comptime op: u4) InstrFn {
|
||||
return struct {
|
||||
|
|
@ -22,96 +17,85 @@ pub fn fmt4(comptime op: u4) InstrFn {
|
|||
const rd = opcode & 0x7;
|
||||
const carry = @boolToInt(cpu.cpsr.c.read());
|
||||
|
||||
const op1 = cpu.r[rd];
|
||||
const op2 = cpu.r[rs];
|
||||
|
||||
var result: u32 = undefined;
|
||||
var overflow: bool = undefined;
|
||||
switch (op) {
|
||||
0x0 => {
|
||||
// AND
|
||||
const result = cpu.r[rd] & cpu.r[rs];
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
0x0 => result = op1 & op2, // AND
|
||||
0x1 => result = op1 ^ op2, // EOR
|
||||
0x2 => result = lsl(true, &cpu.cpsr, op1, @truncate(u8, op2)), // LSL
|
||||
0x3 => result = lsr(true, &cpu.cpsr, op1, @truncate(u8, op2)), // LSR
|
||||
0x4 => result = asr(true, &cpu.cpsr, op1, @truncate(u8, op2)), // ASR
|
||||
0x5 => result = adc(&overflow, op1, op2, carry), // ADC
|
||||
0x6 => result = sbc(op1, op2, carry), // SBC
|
||||
0x7 => result = ror(true, &cpu.cpsr, op1, @truncate(u8, op2)), // ROR
|
||||
0x8 => result = op1 & op2, // TST
|
||||
0x9 => result = 0 -% op2, // NEG
|
||||
0xA => result = op1 -% op2, // CMP
|
||||
0xB => overflow = @addWithOverflow(u32, op1, op2, &result), // CMN
|
||||
0xC => result = op1 | op2, // ORR
|
||||
0xD => result = @truncate(u32, @as(u64, op2) * @as(u64, op1)),
|
||||
0xE => result = op1 & ~op2,
|
||||
0xF => result = ~op2,
|
||||
}
|
||||
|
||||
// Write to Destination Register
|
||||
switch (op) {
|
||||
0x8, 0xA, 0xB => {},
|
||||
else => cpu.r[rd] = result,
|
||||
}
|
||||
|
||||
// Write Flags
|
||||
switch (op) {
|
||||
0x0, 0x1, 0x2, 0x3, 0x4, 0x7, 0xC, 0xE, 0xF => {
|
||||
// Logic Operations
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
// C set by Barrel Shifter, V is unaffected
|
||||
},
|
||||
0x1 => {
|
||||
// EOR
|
||||
const result = cpu.r[rd] ^ cpu.r[rs];
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
0x8, 0xA => {
|
||||
// Test Flags
|
||||
// CMN (0xB) is handled with ADC
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
if (op == 0xA) {
|
||||
// CMP specific
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
},
|
||||
0x2 => {
|
||||
// LSL
|
||||
const result = logicalLeft(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs]));
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
0x3 => {
|
||||
// LSR
|
||||
const result = logicalRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs]));
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
0x4 => {
|
||||
// ASR
|
||||
const result = arithmeticRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs]));
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
0x5 => {
|
||||
// ADC
|
||||
cpu.r[rd] = adc(true, cpu, cpu.r[rd], cpu.r[rs], carry);
|
||||
0x5, 0xB => {
|
||||
// ADC, CMN
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(overflow);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0x6 => {
|
||||
// SBC
|
||||
cpu.r[rd] = sbc(true, cpu, cpu.r[rd], cpu.r[rs], carry);
|
||||
},
|
||||
0x7 => {
|
||||
// ROR
|
||||
const result = rotateRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs]));
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
0x8 => {
|
||||
// TST
|
||||
const result = cpu.r[rd] & cpu.r[rs];
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
const subtrahend = @as(u64, op2) -% carry +% 1;
|
||||
cpu.cpsr.c.write(subtrahend <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0x9 => {
|
||||
// NEG
|
||||
cpu.r[rd] = sub(true, cpu, 0, cpu.r[rs]);
|
||||
},
|
||||
0xA => {
|
||||
// CMP
|
||||
cmp(cpu, cpu.r[rd], cpu.r[rs]);
|
||||
},
|
||||
0xB => {
|
||||
// CMN
|
||||
cmn(cpu, cpu.r[rd], cpu.r[rs]);
|
||||
},
|
||||
0xC => {
|
||||
// ORR
|
||||
const result = cpu.r[rd] | cpu.r[rs];
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(op2 <= 0);
|
||||
cpu.cpsr.v.write(((0 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0xD => {
|
||||
// MUL
|
||||
const temp = @as(u64, cpu.r[rs]) * @as(u64, cpu.r[rd]);
|
||||
const result = @truncate(u32, temp);
|
||||
cpu.r[rd] = result;
|
||||
|
||||
// Multiplication
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
// V is unaffected, assuming similar behaviour to ARMv4 MUL C is undefined
|
||||
},
|
||||
0xE => {
|
||||
// BIC
|
||||
const result = cpu.r[rd] & ~cpu.r[rs];
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
0xF => {
|
||||
// MVN
|
||||
const result = ~cpu.r[rs];
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
},
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
|
|
|
|||
|
|
@ -33,7 +33,8 @@ pub fn fmt14(comptime L: bool, comptime R: bool) InstrFn {
|
|||
if (R) {
|
||||
if (L) {
|
||||
const value = bus.read(u32, address);
|
||||
cpu.r[15] = value & 0xFFFF_FFFE;
|
||||
cpu.r[15] = value & ~@as(u32, 1);
|
||||
cpu.pipe.reload(cpu);
|
||||
} else {
|
||||
bus.write(u32, address, cpu.r[14]);
|
||||
}
|
||||
|
|
@ -52,7 +53,13 @@ pub fn fmt15(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.read(u32, address) else bus.write(u32, address, cpu.r[15] + 4);
|
||||
if (L) {
|
||||
cpu.r[15] = bus.read(u32, address);
|
||||
cpu.pipe.reload(cpu);
|
||||
} else {
|
||||
bus.write(u32, address, cpu.r[15] + 2);
|
||||
}
|
||||
|
||||
cpu.r[rb] += 0x40;
|
||||
return;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -9,16 +9,13 @@ pub fn fmt16(comptime cond: u4) InstrFn {
|
|||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
// B
|
||||
const offset = sext(u32, u8, opcode & 0xFF) << 1;
|
||||
if (cond == 0xE or cond == 0xF)
|
||||
cpu.panic("[CPU/THUMB.16] Undefined conditional branch with condition {}", .{cond});
|
||||
|
||||
const should_execute = switch (cond) {
|
||||
0xE, 0xF => cpu.panic("[CPU/THUMB.16] Undefined conditional branch with condition {}", .{cond}),
|
||||
else => checkCond(cpu.cpsr, cond),
|
||||
};
|
||||
if (!checkCond(cpu.cpsr, cond)) return;
|
||||
|
||||
if (should_execute) {
|
||||
cpu.r[15] = (cpu.r[15] + 2) +% offset;
|
||||
}
|
||||
cpu.r[15] +%= sext(u32, u8, opcode & 0xFF) << 1;
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
@ -27,8 +24,8 @@ pub fn fmt18() InstrFn {
|
|||
return struct {
|
||||
// B but conditional
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
const offset = sext(u32, u11, opcode & 0x7FF) << 1;
|
||||
cpu.r[15] = (cpu.r[15] + 2) +% offset;
|
||||
cpu.r[15] +%= sext(u32, u11, opcode & 0x7FF) << 1;
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
@ -41,13 +38,16 @@ pub fn fmt19(comptime is_low: bool) InstrFn {
|
|||
|
||||
if (is_low) {
|
||||
// Instruction 2
|
||||
const old_pc = cpu.r[15];
|
||||
const next_opcode = cpu.r[15] - 2;
|
||||
|
||||
cpu.r[15] = cpu.r[14] +% (offset << 1);
|
||||
cpu.r[14] = old_pc | 1;
|
||||
cpu.r[14] = next_opcode | 1;
|
||||
|
||||
cpu.pipe.reload(cpu);
|
||||
} else {
|
||||
// Instruction 1
|
||||
cpu.r[14] = (cpu.r[15] + 2) +% (sext(u32, u11, offset) << 12);
|
||||
const lr_offset = sext(u32, u11, offset) << 12;
|
||||
cpu.r[14] = (cpu.r[15] +% lr_offset) & ~@as(u32, 1);
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
|
|
|
|||
|
|
@ -3,14 +3,12 @@ const std = @import("std");
|
|||
const Bus = @import("../../Bus.zig");
|
||||
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
|
||||
const InstrFn = @import("../../cpu.zig").thumb.InstrFn;
|
||||
const shifter = @import("../barrel_shifter.zig");
|
||||
|
||||
const add = @import("../arm/data_processing.zig").add;
|
||||
const sub = @import("../arm/data_processing.zig").sub;
|
||||
const cmp = @import("../arm/data_processing.zig").cmp;
|
||||
const setLogicOpFlags = @import("../arm/data_processing.zig").setLogicOpFlags;
|
||||
|
||||
const log = std.log.scoped(.Thumb1);
|
||||
const lsl = @import("../barrel_shifter.zig").lsl;
|
||||
const lsr = @import("../barrel_shifter.zig").lsr;
|
||||
const asr = @import("../barrel_shifter.zig").asr;
|
||||
|
||||
pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
||||
return struct {
|
||||
|
|
@ -24,7 +22,7 @@ pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
|||
if (offset == 0) {
|
||||
break :blk cpu.r[rs];
|
||||
} else {
|
||||
break :blk shifter.logicalLeft(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
break :blk lsl(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
}
|
||||
},
|
||||
0b01 => blk: {
|
||||
|
|
@ -33,7 +31,7 @@ pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
|||
cpu.cpsr.c.write(cpu.r[rs] >> 31 & 1 == 1);
|
||||
break :blk @as(u32, 0);
|
||||
} else {
|
||||
break :blk shifter.logicalRight(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
break :blk lsr(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
}
|
||||
},
|
||||
0b10 => blk: {
|
||||
|
|
@ -42,7 +40,7 @@ pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
|||
cpu.cpsr.c.write(cpu.r[rs] >> 31 & 1 == 1);
|
||||
break :blk @bitCast(u32, @bitCast(i32, cpu.r[rs]) >> 31);
|
||||
} else {
|
||||
break :blk shifter.arithmeticRight(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
break :blk asr(true, &cpu.cpsr, cpu.r[rs], offset);
|
||||
}
|
||||
},
|
||||
else => cpu.panic("[CPU/THUMB.1] 0b{b:0>2} is not a valid op", .{op}),
|
||||
|
|
@ -50,7 +48,10 @@ pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
|||
|
||||
// Equivalent to an ARM MOVS
|
||||
cpu.r[rd] = result;
|
||||
setLogicOpFlags(true, cpu, result);
|
||||
|
||||
// Write Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
@ -58,28 +59,51 @@ pub fn fmt1(comptime op: u2, comptime offset: u5) InstrFn {
|
|||
pub fn fmt5(comptime op: u2, comptime h1: u1, comptime h2: u1) InstrFn {
|
||||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
const src_idx = @as(u4, h2) << 3 | (opcode >> 3 & 0x7);
|
||||
const dst_idx = @as(u4, h1) << 3 | (opcode & 0x7);
|
||||
const rs = @as(u4, h2) << 3 | (opcode >> 3 & 0x7);
|
||||
const rd = @as(u4, h1) << 3 | (opcode & 0x7);
|
||||
|
||||
const src = if (src_idx == 0xF) (cpu.r[src_idx] + 2) & 0xFFFF_FFFE else cpu.r[src_idx];
|
||||
const dst = if (dst_idx == 0xF) (cpu.r[dst_idx] + 2) & 0xFFFF_FFFE else cpu.r[dst_idx];
|
||||
const op1 = cpu.r[rd];
|
||||
const op2 = cpu.r[rs];
|
||||
|
||||
var result: u32 = undefined;
|
||||
var overflow: bool = undefined;
|
||||
switch (op) {
|
||||
0b00 => {
|
||||
// ADD
|
||||
const sum = add(false, cpu, dst, src);
|
||||
cpu.r[dst_idx] = if (dst_idx == 0xF) sum & 0xFFFF_FFFE else sum;
|
||||
},
|
||||
0b01 => cmp(cpu, dst, src), // CMP
|
||||
0b10 => {
|
||||
// MOV
|
||||
cpu.r[dst_idx] = if (dst_idx == 0xF) src & 0xFFFF_FFFE else src;
|
||||
},
|
||||
0b00 => result = add(&overflow, op1, op2), // ADD
|
||||
0b01 => result = op1 -% op2, // CMP
|
||||
0b10 => result = op2, // MOV
|
||||
0b11 => {},
|
||||
}
|
||||
|
||||
// Write to Destination Register
|
||||
switch (op) {
|
||||
0b01 => {}, // Test Instruction
|
||||
0b11 => {
|
||||
// BX
|
||||
cpu.cpsr.t.write(src & 1 == 1);
|
||||
cpu.r[15] = src & 0xFFFF_FFFE;
|
||||
const is_thumb = op2 & 1 == 1;
|
||||
cpu.r[15] = op2 & ~@as(u32, 1);
|
||||
|
||||
cpu.cpsr.t.write(is_thumb);
|
||||
cpu.pipe.reload(cpu);
|
||||
},
|
||||
else => {
|
||||
cpu.r[rd] = result;
|
||||
if (rd == 0xF) {
|
||||
cpu.r[15] &= ~@as(u32, 1);
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
},
|
||||
}
|
||||
|
||||
// Write Flags
|
||||
switch (op) {
|
||||
0b01 => {
|
||||
// CMP
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0b00, 0b10, 0b11 => {}, // MOV and Branch Instruction
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
|
|
@ -90,21 +114,28 @@ pub fn fmt2(comptime I: bool, is_sub: bool, rn: u3) InstrFn {
|
|||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
const rs = opcode >> 3 & 0x7;
|
||||
const rd = @truncate(u3, opcode);
|
||||
const op1 = cpu.r[rs];
|
||||
const op2: u32 = if (I) rn else cpu.r[rn];
|
||||
|
||||
if (is_sub) {
|
||||
// SUB
|
||||
cpu.r[rd] = if (I) blk: {
|
||||
break :blk sub(true, cpu, cpu.r[rs], rn);
|
||||
} else blk: {
|
||||
break :blk sub(true, cpu, cpu.r[rs], cpu.r[rn]);
|
||||
};
|
||||
const result = op1 -% op2;
|
||||
cpu.r[rd] = result;
|
||||
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
} else {
|
||||
// ADD
|
||||
cpu.r[rd] = if (I) blk: {
|
||||
break :blk add(true, cpu, cpu.r[rs], rn);
|
||||
} else blk: {
|
||||
break :blk add(true, cpu, cpu.r[rs], cpu.r[rn]);
|
||||
};
|
||||
var overflow: bool = undefined;
|
||||
const result = add(&overflow, op1, op2);
|
||||
cpu.r[rd] = result;
|
||||
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
cpu.cpsr.c.write(overflow);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (op2 ^ result)) >> 31 & 1 == 1);
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
|
|
@ -113,17 +144,36 @@ pub fn fmt2(comptime I: bool, is_sub: bool, rn: u3) InstrFn {
|
|||
pub fn fmt3(comptime op: u2, comptime rd: u3) InstrFn {
|
||||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
const offset = @truncate(u8, opcode);
|
||||
const op1 = cpu.r[rd];
|
||||
const op2: u32 = opcode & 0xFF; // Offset
|
||||
|
||||
var overflow: bool = undefined;
|
||||
const result: u32 = switch (op) {
|
||||
0b00 => op2, // MOV
|
||||
0b01 => op1 -% op2, // CMP
|
||||
0b10 => add(&overflow, op1, op2), // ADD
|
||||
0b11 => op1 -% op2, // SUB
|
||||
};
|
||||
|
||||
// Write to Register
|
||||
if (op != 0b01) cpu.r[rd] = result;
|
||||
|
||||
// Write Flags
|
||||
cpu.cpsr.n.write(result >> 31 & 1 == 1);
|
||||
cpu.cpsr.z.write(result == 0);
|
||||
|
||||
switch (op) {
|
||||
0b00 => {
|
||||
// MOV
|
||||
cpu.r[rd] = offset;
|
||||
setLogicOpFlags(true, cpu, offset);
|
||||
0b00 => {}, // MOV | C set by Barrel Shifter, V is unaffected
|
||||
0b01, 0b11 => {
|
||||
// SUB, CMP
|
||||
cpu.cpsr.c.write(op2 <= op1);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (~op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0b10 => {
|
||||
// ADD
|
||||
cpu.cpsr.c.write(overflow);
|
||||
cpu.cpsr.v.write(((op1 ^ result) & (op2 ^ result)) >> 31 & 1 == 1);
|
||||
},
|
||||
0b01 => cmp(cpu, cpu.r[rd], offset), // CMP
|
||||
0b10 => cpu.r[rd] = add(true, cpu, cpu.r[rd], offset), // ADD
|
||||
0b11 => cpu.r[rd] = sub(true, cpu, cpu.r[rd], offset), // SUB
|
||||
}
|
||||
}
|
||||
}.inner;
|
||||
|
|
@ -133,10 +183,9 @@ pub fn fmt12(comptime isSP: bool, comptime rd: u3) InstrFn {
|
|||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
|
||||
// ADD
|
||||
const left = if (isSP) cpu.r[13] else (cpu.r[15] + 2) & 0xFFFF_FFFD;
|
||||
const left = if (isSP) cpu.r[13] else cpu.r[15] & ~@as(u32, 2);
|
||||
const right = (opcode & 0xFF) << 2;
|
||||
const result = left + right;
|
||||
cpu.r[rd] = result;
|
||||
cpu.r[rd] = left + right;
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -12,7 +12,9 @@ pub fn fmt6(comptime rd: u3) InstrFn {
|
|||
fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u16) void {
|
||||
// LDR
|
||||
const offset = (opcode & 0xFF) << 2;
|
||||
cpu.r[rd] = bus.read(u32, (cpu.r[15] + 2 & 0xFFFF_FFFD) + offset);
|
||||
|
||||
// Bit 1 of the PC intentionally ignored
|
||||
cpu.r[rd] = bus.read(u32, (cpu.r[15] & ~@as(u32, 2)) + offset);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -6,7 +6,7 @@ pub fn fmt17() InstrFn {
|
|||
return struct {
|
||||
fn inner(cpu: *Arm7tdmi, _: *Bus, _: u16) void {
|
||||
// Copy Values from Current Mode
|
||||
const r15 = cpu.r[15];
|
||||
const ret_addr = cpu.r[15] - 2;
|
||||
const cpsr = cpu.cpsr.raw;
|
||||
|
||||
// Switch Mode
|
||||
|
|
@ -14,9 +14,10 @@ pub fn fmt17() InstrFn {
|
|||
cpu.cpsr.t.write(false); // Force ARM Mode
|
||||
cpu.cpsr.i.write(true); // Disable normal interrupts
|
||||
|
||||
cpu.r[14] = r15; // Resume Execution
|
||||
cpu.r[14] = ret_addr; // Resume Execution
|
||||
cpu.spsr.raw = cpsr; // Previous mode CPSR
|
||||
cpu.r[15] = 0x0000_0008;
|
||||
cpu.pipe.reload(cpu);
|
||||
}
|
||||
}.inner;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -60,11 +60,12 @@ pub fn main() anyerror!void {
|
|||
|
||||
var bus: Bus = undefined;
|
||||
var cpu = Arm7tdmi.init(&scheduler, &bus, log_file);
|
||||
if (paths.bios == null) cpu.fastBoot();
|
||||
|
||||
try bus.init(allocator, &scheduler, &cpu, paths);
|
||||
defer bus.deinit();
|
||||
|
||||
if (paths.bios == null) cpu.fastBoot();
|
||||
|
||||
var gui = Gui.init(&bus.pak.title, &bus.apu, width, height);
|
||||
defer gui.deinit();
|
||||
|
||||
|
|
|
|||
|
|
@ -176,6 +176,7 @@ pub const Logger = struct {
|
|||
|
||||
pub fn print(self: *Self, comptime format: []const u8, args: anytype) !void {
|
||||
try self.buf.writer().print(format, args);
|
||||
try self.buf.flush(); // FIXME: On panics, whatever is in the buffer isn't written to file
|
||||
}
|
||||
|
||||
pub fn mgbaLog(self: *Self, cpu: *const Arm7tdmi, opcode: u32) void {
|
||||
|
|
@ -215,7 +216,7 @@ pub const Logger = struct {
|
|||
cpu.r[12],
|
||||
cpu.r[13],
|
||||
cpu.r[14],
|
||||
cpu.r[15],
|
||||
cpu.r[15] - if (cpu.cpsr.t.read()) 2 else @as(u32, 4),
|
||||
cpu.cpsr.raw,
|
||||
opcode,
|
||||
};
|
||||
|
|
|
|||
Loading…
Reference in New Issue