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feat(cpu): implement like 1 THUMB instruction

This commit is contained in:
Rekai Nyangadzayi Musuka 2022-01-14 07:25:44 -04:00
parent 4606a1ab25
commit f10670d5e3
1 changed files with 13 additions and 4 deletions
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17
src/cpu.zig
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@ -7,6 +7,7 @@ const Bit = @import("bitfield").Bit;
const Bitfield = @import("bitfield").Bitfield; const Bitfield = @import("bitfield").Bitfield;
const Scheduler = @import("scheduler.zig").Scheduler; const Scheduler = @import("scheduler.zig").Scheduler;
// ARM Instruction Groups
const dataProcessing = @import("cpu/arm/data_processing.zig").dataProcessing; const dataProcessing = @import("cpu/arm/data_processing.zig").dataProcessing;
const psrTransfer = @import("cpu/arm/psr_transfer.zig").psrTransfer; const psrTransfer = @import("cpu/arm/psr_transfer.zig").psrTransfer;
const singleDataTransfer = @import("cpu/arm/single_data_transfer.zig").singleDataTransfer; const singleDataTransfer = @import("cpu/arm/single_data_transfer.zig").singleDataTransfer;
@ -15,6 +16,9 @@ const blockDataTransfer = @import("cpu/arm/block_data_transfer.zig").blockDataTr
const branch = @import("cpu/arm/branch.zig").branch; const branch = @import("cpu/arm/branch.zig").branch;
const branchAndExchange = @import("cpu/arm/branch.zig").branchAndExchange; const branchAndExchange = @import("cpu/arm/branch.zig").branchAndExchange;
// THUMB Instruction Groups
const format3 = @import("cpu/thumb/format3.zig").format3;
pub const ArmInstrFn = fn (*Arm7tdmi, *Bus, u32) void; pub const ArmInstrFn = fn (*Arm7tdmi, *Bus, u32) void;
pub const ThumbInstrFn = fn (*Arm7tdmi, *Bus, u16) void; pub const ThumbInstrFn = fn (*Arm7tdmi, *Bus, u16) void;
const arm_lut: [0x1000]ArmInstrFn = armPopulate(); const arm_lut: [0x1000]ArmInstrFn = armPopulate();
@ -141,12 +145,17 @@ fn checkCond(cpsr: PSR, cond: u4) bool {
fn thumbPopulate() [0x400]ThumbInstrFn { fn thumbPopulate() [0x400]ThumbInstrFn {
return comptime { return comptime {
@setEvalBranchQuota(0x800); @setEvalBranchQuota(0xC00);
var lut = [_]ThumbInstrFn{thumbUndefined} ** 0x400; var lut = [_]ThumbInstrFn{thumbUndefined} ** 0x400;
var i: usize = 0; var i: usize = 0;
while (i < lut.len) : (i += 1) { while (i < lut.len) : (i += 1) {
lut[i] = thumbUndefined; if (i >> 7 & 0x7 == 0b001) {
const op = i >> 5 & 0x3;
const rd = i >> 2 & 0x7;
lut[i] = format3(op, rd);
}
} }
return lut; return lut;
@ -245,10 +254,10 @@ const Mode = enum(u5) {
fn armUndefined(_: *Arm7tdmi, _: *Bus, opcode: u32) void { fn armUndefined(_: *Arm7tdmi, _: *Bus, opcode: u32) void {
const id = armIdx(opcode); const id = armIdx(opcode);
std.debug.panic("[CPU:ARM] {{0x{X:}}} 0x{X:} is an illegal opcode", .{ id, opcode }); std.debug.panic("[CPU:ARM] ID: 0x{X:0>3} 0x{X:0>8} is an illegal opcode", .{ id, opcode });
} }
fn thumbUndefined(_: *Arm7tdmi, _: *Bus, opcode: u16) void { fn thumbUndefined(_: *Arm7tdmi, _: *Bus, opcode: u16) void {
const id = thumbIdx(opcode); const id = thumbIdx(opcode);
std.debug.panic("[CPU:THUMB] {{0x{X:}}} 0x{X:} is an illegal opcode", .{ id, opcode }); std.debug.panic("[CPU:THUMB] ID: 0b{b:0>10} 0x{X:0>2} is an illegal opcode", .{ id, opcode });
} }