X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=hacks%2Fasm6502.c;h=90eed8d1d7ac3c762f3e8c75a15ccfc3233532f6;hp=101ee5a6a416a98fbeadf7b0abca1b23f91d82a5;hb=7b34ef992563d7bcbb64cc5597dc45fa24470b05;hpb=c1b9b55ad8d59dc05ef55e316aebf5863e7dfa56 diff --git a/hacks/asm6502.c b/hacks/asm6502.c index 101ee5a6..90eed8d1 100644 --- a/hacks/asm6502.c +++ b/hacks/asm6502.c @@ -1027,7 +1027,7 @@ static void jmpSTY(machine_6502 *machine, AddrMode adm){ static void assignOpCodes(Opcodes *opcodes){ #define SETOP(num, _name, _Imm, _ZP, _ZPX, _ZPY, _ABS, _ABSX, _ABSY, _INDX, _INDY, _SNGL, _BRA, _func) \ -{opcodes[num].name[4] = '\0'; \ +{opcodes[num].name[3] = '\0'; \ strncpy(opcodes[num].name, _name, 3); opcodes[num].Imm = _Imm; opcodes[num].ZP = _ZP; \ opcodes[num].ZPX = _ZPX; opcodes[num].ZPY = _ZPY; opcodes[num].ABS = _ABS; \ opcodes[num].ABSX = _ABSX; opcodes[num].ABSY = _ABSY; opcodes[num].INDX = _INDX; \ @@ -1897,12 +1897,11 @@ static BOOL translate(Opcodes *op,Param *param, machine_6502 *machine){ else { if (op->BRA) { pushByte(machine, op->BRA); - if (param->lbladdr < (machine->codeLen + PROG_START)) - pushByte(machine, - (0xff - (machine->codeLen-param->lbladdr)) & 0xff); - else - pushByte(machine, - (param->lbladdr - machine->codeLen-1) & 0xff); + { + int diff = abs(param->lbladdr - machine->defaultCodePC); + int backward = (param->lbladdr < machine->defaultCodePC); + pushByte(machine, (backward) ? 0xff - diff : diff - 1); + } } else { fprintf(stderr,"%s does not take BRANCH parameters.\n",op->name); @@ -1993,14 +1992,28 @@ static BOOL compileLine(AsmLine *asmline, void *args){ static BOOL indexLabels(AsmLine *asmline, void *arg){ machine_6502 *machine; int thisPC; + Bit16 oldDefault; machine = arg; + oldDefault = machine->defaultCodePC; thisPC = machine->regPC; /* Figure out how many bytes this instruction takes */ machine->codeLen = 0; + if ( ! compileLine(asmline, machine) ){ return FALSE; } - machine->regPC += machine->codeLen; + + /* If the machine's defaultCodePC has changed then we encountered a + *= which changes the load address. We need to initials our code + *counter with the current default. */ + if (oldDefault == machine->defaultCodePC){ + machine->regPC += machine->codeLen; + } + else { + machine->regPC = machine->defaultCodePC; + oldDefault = machine->defaultCodePC; + } + if (asmline->labelDecl) { asmline->label->addr = thisPC; } @@ -2040,6 +2053,20 @@ static BOOL compileCode(machine_6502 *machine, const char *code){ return FALSE; /* update label references */ linkLabels(asmlist); + +#if 0 /* prints out some debugging information */ + { + AsmLine *p; + if(asmlist != NULL){ + for (p = asmlist; p != NULL; p = p->next) + fprintf(stderr,"%s lbl: %s addr: %d ParamLbl: %s ParamAddr: %d\n", + p->command, p->label->label, p->label->addr, + p->param->label, p->param->lbladdr); + } + } + +#endif + /* Second pass: translate the instructions */ machine->codeLen = 0; /* Link label call push_byte which increments defaultCodePC.