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feat(cpu): decode and implement all necessary ARM CPU instructions

This commit is contained in:
Rekai Nyangadzayi Musuka 2022-10-21 05:12:10 -03:00
parent 151de2eab4
commit 696cc1b359
1 changed files with 14 additions and 3 deletions
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17
src/cpu.zig
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@ -492,7 +492,7 @@ fn thumbPopulate() [0x400]ThumbInstrFn {
fn armPopulate() [0x1000]ArmInstrFn { fn armPopulate() [0x1000]ArmInstrFn {
return comptime { return comptime {
@setEvalBranchQuota(0xC000); // TODO: Figure out exact size @setEvalBranchQuota(0xE000);
var lut = [_]ArmInstrFn{armUndefined} ** 0x1000; var lut = [_]ArmInstrFn{armUndefined} ** 0x1000;
var i: usize = 0; var i: usize = 0;
@ -558,7 +558,11 @@ fn armPopulate() [0x1000]ArmInstrFn {
} }
// Instructions with Opcode[27] == 1 // Instructions with Opcode[27] == 1
if (i >> 9 & 0x7 == 0b100) { if (i >> 8 & 0xF == 0b1110) {
// bits 27:24
// Coprocessor Data Opertation + Register Transfer
lut[i] = armUndefined;
} else if (i >> 9 & 0x7 == 0b100) {
// Bits 27:25 // Bits 27:25
const P = i >> 8 & 1 == 1; const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1; const U = i >> 7 & 1 == 1;
@ -571,7 +575,14 @@ fn armPopulate() [0x1000]ArmInstrFn {
// Bits 27:25 // Bits 27:25
const L = i >> 8 & 1 == 1; const L = i >> 8 & 1 == 1;
lut[i] = branch(L); lut[i] = branch(L);
} else if (i >> 8 & 0xF == 0b1111) lut[i] = softwareInterrupt(); // Bits 27:24 } else if (i >> 9 & 0x7 == 0b110) {
// Bits 27:25
// Coprocessor Data Transfer
lut[i] = armUndefined;
} else if (i >> 8 & 0xF == 0b1111) {
// Bits 27:24
lut[i] = softwareInterrupt();
}
} }
return lut; return lut;