91 lines
2.7 KiB
C
91 lines
2.7 KiB
C
/* Copyright (c) 2005 Ian Piumarta
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* Copyright (c) 2014 Steven Flintham
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*
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* All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the 'Software'),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, provided that the above copyright notice(s) and this
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* permission notice appear in all copies of the Software and that both the
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* above copyright notice(s) and this permission notice appear in supporting
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* documentation.
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*
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* THE SOFTWARE IS PROVIDED 'AS IS'. USE ENTIRELY AT YOUR OWN RISK.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "lib6502.h"
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#include "test-utils.h"
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int done(M6502 *mpu, uint16_t address, uint8_t data)
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{
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char buffer[64];
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M6502_dump_masked(mpu, buffer);
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printf("\nBRK instruction: address %04X opcode %02X\n%s\n", address, data, buffer);
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exit(0);
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}
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int oswrch(M6502 *mpu, uint16_t address, uint8_t data)
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{
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putchar(mpu->registers->a);
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mpu->memory[0xffee] = 0x60; // RTS
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return 0;
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}
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# define gen1(X) (mpu->memory[pc++]= (uint8_t)(X))
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# define gen2(X,Y) gen1(X); gen1(Y)
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# define gen3(X,Y,Z) gen1(X); gen2(Y,Z)
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int main(int argc, char *argv[])
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{
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M6502 *mpu = M6502_new(0, 0, 0);
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parse_args(argc, argv, mpu);
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unsigned pc = 0x1000;
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unsigned saved_pc;
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M6502_setCallback(mpu, call, 0, done );
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M6502_setCallback(mpu, call, 0xffee, oswrch);
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gen2(0xa2, 0xff ); // LDX #&FF
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gen1(0x9a ); // TXS
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gen2(0xa9, 'A' ); // LDA #'A'
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// LDA #'B' is 0xa9, 0x42. So if we execute a JSR at 0x42a7, it will
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// push 0x42 and then 0xa9 onto the stack. Since the stack grows downwards
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// those bytes will be in the right order for execution.
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gen3(0x4c, 0xa7, 0x42); // JMP &42A7
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pc = 0x42a7;
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gen3(0x20, 0x00, 0x30); // JSR &3000
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saved_pc = pc;
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pc = 0x3000;
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gen3(0x4c, 0xfe, 0x01); // JMP &01FE
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pc = 0x200;
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gen3(0x20, 0xee, 0xff); // JSR &FFEE
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gen1(0x60 ); // RTS
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pc = saved_pc;
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// Let's do the same thing again, but this time code has already been
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// executed from that address on the stack, so we're verifying the change
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// is picked up. We do LDA #'C' this time, so we execute the JSR from
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// 0x43a7.
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gen3(0x4c, 0xa7, 0x43); // JMP &43A7
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pc = 0x43a7;
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gen3(0x20, 0x00, 0x30); // JSR &3000
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gen2(0x00, 0x00 ); // BRK
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M6502_setVector(mpu, RST, 0x1000);
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M6502_reset(mpu);
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M6502_run(mpu);
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M6502_delete(mpu); /* We never reach here, but what the hey. */
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return 0;
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}
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