Retro/pcjs
Watch
1
0
Fork
You've already forked pcjs
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Scaffolding for 32-bit ModRM decoding

Browse source
This commit is contained in:
Jeff Parsons 2015-01-20 22:13:40 -08:00 • committed by jeffpar
commit 7cdf097c8d
9 changed files with 22819 additions and 2522 deletions
Download patch file Download diff file Expand all files Collapse all files

41
modules/pcjs/bin/x86gen.js
View file

@ -75,6 +75,9 @@ var w, sError = "";
var fGenMods = true;
var sEAFuncs = "";
var aBase = ["EAX", "ECX", "EDX", "EBX", "ESP", "EBP", "ESI", "EDI"];
var aIndex = ["EAX", "ECX", "EDX", "EBX", "none", "EBP", "ESI", "EDI"];
if (!fGenMods) {
var sOps = "", cOps = 0;
@ -256,11 +259,37 @@ else {
}
}
sContainer = "X86ModSIB" + ".aOpModSIB";
print(sContainer + " = [");
for (var sib = 0x00; sib <= 0xff && !sError; sib++) {
genSIB(sib);
}
print("];\n");
if (sEAFuncs) {
print("var X86Mods = {\n" + sEAFuncs + "};\n");
}
}
function genSIB(sib) {
var scale = (sib >> 6);
var index = (sib >> 3) & 0x7;
var base = (sib & 0x7);
var sFunc = "opModSIB" + toHex(sib, 2);
print(" /**");
print(" * " + sFunc + "(): scale=" + toBin(scale, 2) + " (" + toHex(1 << scale, 1) + ") index=" + toBin(index, 3) + " (" + aIndex[index] + ") base=" + toBin(base, 3) + " (" + (base == 5? "mod? EBP : disp32)" : aBase[base] + ")"));
print(" *");
print(" * @this {X86CPU}");
print(" * @param {number} mod");
print(" */");
print(" function " + sFunc + "(mod) {");
var sBase = (base == 5? "(mod? this.reg" + aBase[base] + " : this.getIPWord())" : "this.reg" + aBase[base]);
if (index != 4) sBase += " + (this.reg" + (aIndex[index] + " << " + scale) + ")";
print(" return " + sBase + ";");
print(" }" + (sib < 255? "," : ""));
}
function genMode(a, d, w, mrm, sGroup, sRO) {
var mod = (mrm >> 6);
var reg = (mrm >> 3) & 0x7;
@ -680,7 +709,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
nCycles = "this.CYCLES.nEACyclesBase";
break;
case 4:
sModAddr = "this.getSIB()";
sModAddr = "this.getSIB(0)";
sModFunc = "SIB";
nCycles = "this.CYCLES.nEACyclesBase";
break;
@ -727,7 +756,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
nCycles = "this.CYCLES.nEACyclesBaseDisp";
break;
case 4:
sModAddr = "this.getSIB() + this.getIPDisp()";
sModAddr = "this.getSIB(1) + this.getIPDisp()";
sModFunc = "SIBD8";
nCycles = "this.CYCLES.nEACyclesBaseDisp";
break;
@ -774,7 +803,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
nCycles = "this.CYCLES.nEACyclesBaseDisp";
break;
case 4:
sModAddr = "this.getSIB() + this.getIPWord()";
sModAddr = "this.getSIB(2) + this.getIPWord()";
sModFunc = "SIBD32";
nCycles = "this.CYCLES.nEACyclesBaseDisp";
break;
@ -917,7 +946,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
return null;
}
sOpMod = "opMod" + aOpPrefix[w] + aAddrPrefix[a] + (sGroup? sGroup + (sRO? sRO : "") : aDst[d]) + toHex(mrm, 2);
sOpMod = "opMod" + aAddrPrefix[a] + (sGroup? sGroup + (sRO? sRO : "") : aDst[d]) + aSize[w] + toHex(mrm, 2);
var sTemp = aSize[w].charAt(0).toLowerCase();
@ -926,7 +955,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
* Use this to generate ModRM decoders that accept an array (ie, "group") of functions, and pass along an implied argument as well
*/
if (sRO && reg != 7) {
sOpMod = "opMod" + aSize[w] + aAddrPrefix[a] + (sGroup? sGroup : aDst[d]) + toHex(mrm, 2);
sOpMod = "opMod" + aAddrPrefix[a] + (sGroup? sGroup : aDst[d]) + aSize[w] + toHex(mrm, 2);
return sOpMod;
}
@ -1023,7 +1052,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
if (mod == 3 && !d) {
var mrmPrime = (mod << 6) | (r_m << 3) | reg;
print(" X86Mod" + aOpPrefix[w] + aAddrPrefix[a] + ".aOpModReg[0x" + toHex(mrmPrime, 2) + "],");
sOpMod = "opMod" + aOpPrefix[w] + aAddrPrefix[a] + aDst[1] + toHex(mrmPrime, 2);
sOpMod = "opMod" + aAddrPrefix[a] + aDst[1] + aSize[w] + toHex(mrmPrime, 2);
return sOpMod;
}