diff --git a/src/bus/io.zig b/src/bus/io.zig index 8e38187..8950aea 100644 --- a/src/bus/io.zig +++ b/src/bus/io.zig @@ -30,7 +30,7 @@ pub const Io = struct { pub fn write16(self: *@This(), addr: u32, halfword: u16) void { switch (addr) { 0x0400_000 => self.dispcnt.val = halfword, - else => std.debug.panic("[I/O:16] tried to write {X:} to {X:}", .{ halfword, addr }), + else => std.debug.panic("[I/O:16] tried to write 0x{X:} to 0x{X:}", .{ halfword, addr }), } } diff --git a/src/cpu.zig b/src/cpu.zig index 18b995c..b2c6cfe 100644 --- a/src/cpu.zig +++ b/src/cpu.zig @@ -29,6 +29,19 @@ pub const Arm7tdmi = struct { }; } + pub fn skipBios(self: *@This()) void { + self.r[0] = 0x08000000; + self.r[1] = 0x000000EA; + // GPRs 2 -> 12 *should* already be 0 initialized + self.r[13] = 0x0300_7F00; + self.r[14] = 0x0000_0000; + self.r[15] = 0x0800_0000; + + // TODO: Set sp_irq = 0x0300_7FA0, sp_svc = 0x0300_7FE0 + + self.cpsr.val = 0x6000001F; + } + pub inline fn step(self: *@This()) u64 { std.debug.print("PC: 0x{X:} ", .{self.r[15]}); const opcode = self.fetch(); diff --git a/src/main.zig b/src/main.zig index a75db88..a21849e 100644 --- a/src/main.zig +++ b/src/main.zig @@ -27,6 +27,8 @@ pub fn main() anyerror!void { var scheduler = Scheduler.init(alloc); var cpu = Arm7tdmi.init(&scheduler, &bus); + cpu.skipBios(); + while (true) { emu.runFrame(&scheduler, &cpu, &bus); }