src/bus/io.zig

@@ -21,7 +21,7 @@ pub const Io = struct {
             .vcount = .{ .raw = 0x0000 },
             .ime = false,
             .ie = .{ .raw = 0x0000 },
-            .keyinput = .{ .raw = 0x03FF },
+            .keyinput = .{ .raw = 0x01FF },
         };
     }
 

src/cpu.zig

@@ -18,7 +18,6 @@ const branch = @import("cpu/arm/branch.zig").branch;
 const branchAndExchange = @import("cpu/arm/branch.zig").branchAndExchange;
 const softwareInterrupt = @import("cpu/arm/software_interrupt.zig").softwareInterrupt;
 const multiply = @import("cpu/arm/multiply.zig").multiply;
-const multiplyLong = @import("cpu/arm/multiply_long.zig").multiplyLong;
 
 // THUMB Instruction Groups
 const format1 = @import("cpu/thumb/format1.zig").format1;
@@ -534,14 +533,6 @@ fn armPopulate() [0x1000]ArmInstrFn {
                 lut[i] = multiply(A, S);
             }
 
-            if (i >> 7 & 0x1F == 0b00001 and i & 0xF == 0b1001) {
-                const U = i >> 6 & 1 == 1;
-                const A = i >> 5 & 1 == 1;
-                const S = i >> 4 & 1 == 1;
-
-                lut[i] = multiplyLong(U, A, S);
-            }
-
             if (i >> 10 & 0x3 == 0b01) {
                 const I = i >> 9 & 1 == 1;
                 const P = i >> 8 & 1 == 1;

src/cpu/arm/multiply_long.zig

@@ -1,38 +0,0 @@
-const std = @import("std");
-
-const Bus = @import("../../Bus.zig");
-const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
-const InstrFn = @import("../../cpu.zig").ArmInstrFn;
-
-pub fn multiplyLong(comptime U: bool, comptime A: bool, comptime S: bool) InstrFn {
-    return struct {
-        fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
-            const rd_hi = opcode >> 16 & 0xF;
-            const rd_lo = opcode >> 12 & 0xF;
-            const rs = opcode >> 8 & 0xF;
-            const rm = opcode & 0xF;
-
-            if (U) {
-                // Signed (WHY IS IT U THEN?)
-                var result: i64 = @as(i64, @bitCast(i32, cpu.r[rm])) * @as(i64, @bitCast(i32, cpu.r[rs]));
-                if (A) result += @bitCast(i64, @as(u64, cpu.r[rd_hi]) << 32 | @as(u64, cpu.r[rd_lo]));
-
-                cpu.r[rd_hi] = @bitCast(u32, @truncate(i32, result >> 32));
-                cpu.r[rd_lo] = @bitCast(u32, @truncate(i32, result));
-            } else {
-                // Unsigned
-                var result: u64 = @as(u64, cpu.r[rm]) * @as(u64, cpu.r[rs]);
-                if (A) result += @as(u64, cpu.r[rd_hi]) << 32 | @as(u64, cpu.r[rd_lo]);
-
-                cpu.r[rd_hi] = @truncate(u32, result >> 32);
-                cpu.r[rd_lo] = @truncate(u32, result);
-            }
-
-            if (S) {
-                cpu.cpsr.z.write(cpu.r[rd_hi] == 0 and cpu.r[rd_lo] == 0);
-                cpu.cpsr.n.write(cpu.r[rd_hi] >> 31 & 1 == 1);
-                // C and V are set to meaningless values
-            }
-        }
-    }.inner;
-}