VRac/M6502/M6502.pm

package M6502;

use strict;
use warnings;

use Data::Dump qw/dump/;
use Carp qw/confess/;
use Exporter 'import';
our @EXPORT = qw'dump_R @mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $debug';
our $VERSION = '0.0.4';
require XSLoader;
XSLoader::load('M6502', $VERSION);

=head1 NAME

M6502 - perl bindings for M6502 CPU emulator

=head1 FUNCTIONS

=cut

our $debug = 0;

our @mem;
#@mem = (0xff) x 0x10000;       # 64M
tie @mem, 'M6502::TieMem';

# program counter
our $PC = 0xbeef;
# CPU registars
our ( $A, $P, $X, $Y, $S ) = (0) x 5;

our $IPeriod=1;         # Set IPeriod to number of CPU cycles between calls to Loop6502
our $ICount;
our $IRequest;          # Set to the INT_IRQ when pending IRQ
our $IAutoReset;        # Set to 1 to autom. reset IRequest
our $TrapBadOps=1;      # Set to 1 to warn of illegal opcodes
our $Trap;                      # Set Trap to address to trace from
our $Trace;                     # Set Trace=1 to start tracing

=head2 init

Setup read and write memory hooks (to implement memory mapped devices)

  $init->(
        read => sub {
                return $mem[$_[0]];
        },
        write => sub {
                $mem[$_[0]] = $_[1];
        },
  );

=cut

our $_rw_hooks = {
        read => sub {
                warn sprintf("# callback read(%04x) not implemented\n", @_) if $debug;
                return $mem[$_[0]];
        },
        write => sub {
                warn sprintf("# callback write(%04x,%02x) not implemented", @_) if $debug;
                $mem[$_[0]] = $_[1];
        },
};

sub init {
        my $self = shift;
        my $args = {@_};
        warn "inside init low-level M6502 from ",ref($self),"\n";

        foreach my $p ( qw/read write/ ) {
                confess "need $p argument as coderef" unless ( $args->{$p} && ref($args->{$p}) eq 'CODE' );
                $_rw_hooks->{$p} = $args->{$p};
        }

};

=head2 poke_code

Write series of bytes into memory passing through MMU (C<read> and C<write>)
functions. If you don't want to trigger MMU, use C<write_chunk>.

  $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );

=cut

sub poke_code {
        my $self = shift;
        my $addr = shift;
        warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
        # call low-level write
        #$_rw_hooks->{write}->( $addr++, $_ ) foreach @_;
        $mem[$addr++] = $_ foreach @_;
}

=head2 ram

Read series of bytes into memory without MMU interaction

  my @code = $emu->ram( 0xc000, 0xc1000 );

=cut

sub ram {
        my $self = shift;
        my ( $from, $to ) = @_;
        warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
#       return @mem[ $from .. $to ];
        return unpack('C*', M6502::mem_peek_region( $from, $to ));
}

=head2 write_chunk

Low-level update of memory, overriding user specified MMU functions C<read> and C<write>

  $emu->write_chunk( $address, $chunk_of_data );

=cut

sub write_chunk {
        my ($self, $addr, $chunk) = @_;
        my $len = length($chunk);
        splice @mem, $addr, $len, unpack('C*', $chunk);
}

=head1 XS Callbacks

This functions are called from C<M6502.xs>

=head2 _read

Read from memory C callback

  $byte = M6502::_read( $address );

=cut

sub _read {
        return $_rw_hooks->{read}->( @_ );
}

=head2 _write

Write into memory C callback

  M6502:_write( $address, $byte );

=cut

sub _write {
        return $_rw_hooks->{write}->( @_ );
}

=head2 _update_perl_R

called by C<M6502.xs> to push changes in registars back to perl variables

=cut

sub _update_perl_R {
        warn "## M6502::update_perl_R(",dump(@_),")\n" if $debug;
        ( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
        dump_R();
}

=head1 XS

Following functions are implemented in C<M6502.xs> and exported to perl.

=head2 set_debug

  M6502::set_debug( 0 );

=head2 get_debug

  my $debug = M6502::set_debug();

=head2 reset

Reset 6502 CPU, reading PC from C<0xfffc>

  M6502::reset();

=head2 update_C_R

Push perl notion of register values to CPU emulator

  M6502::update_C_R();

=head2 update_perl_R

Update perl notion of register values

  M6502::update_perl_R();

=head2 exec

Execute cpu for specified number of cycles

  my $cycles_left = M6502::exec( $execute_cpu_cycles );

=head1 Helpers

=head2 dump_R

helper function which dumps registers in humanly readable form

  my $dump = dump_R;

=cut

sub dump_R {
        my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x "
                . "IPeriod:%d ICount:%d IRequest:%02x IAutoReset:%02x TrapBadOps:%d Trap:%d Trace:%d"
                . "\n",
                $PC, $A, $P, $X, $Y, $S, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace,
        );
        warn "## M6502::dump_R $dump" if $debug;
        return $dump;
}

=head2 debug

Turn perl and C-level debugging on/off

  $emu->debug( 0 );
  $emu->debug( 1 );
  print $emu->debug;

=cut

sub debug {
        my $self = shift;
        my $value = shift;
        if (defined($value)) {
                $debug = M6502::set_debug($value);
        } else {
                $debug = M6502::get_debug();
        }
        return $debug;
}

=head1 SEE ALSO

L<Orao> is sample implementation using this module

=head1 AUTHOR

Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>

=head1 COPYRIGHT & LICENSE

Copyright 2007-8 Dobrica Pavlinusic, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=cut

package M6502::TieMem;

use strict;
use warnings;
use Tie::Array;
use base qw(Tie::Array);

#
sub TIEARRAY {
        my $class = shift;
#       my $opt   = shift;
#       my $self  = { %$opt };
        my $self = {};
        bless($self, __PACKAGE__);
        return $self;
}

sub DESTROY {}

#
sub FETCH {
        my $self = shift;
        my $n    = shift;
        my $val = M6502::mem_peek( $n );
#       warn sprintf("FETCH %04x = %02x\n", $n, $val);
        return $val;
}

#
sub FETCHSIZE {
        return 0xffff;
}

#
sub STORE {
        my $self = shift;
        my $n    = shift;
        my $val  = shift;
        if ( $n > 0xffff ) {
                warn "over 64k: $n\n";
                return;
        }
        M6502::mem_poke( $n, $val );
#       warn sprintf("STORE %04x <- %02x\n",$n, $val);
        return $val;
}

#
sub STORESIZE {
        die('not allowed (yet)');
}

sub PUSH {
        die('not allowed (yet)');
}

sub POP {
        die('not allowed (yet)');
}

sub SHIFT {
        die('not allowed (yet)');
}

sub UNSHIFT {
        die('not allowed (yet)');
}

sub DELETE {
        my $self = shift;
        my $n    = shift;
        $self->STORE($n, 0);
}

sub EXISTS {
        my $self = shift;
        my $n    = shift;
        return 0 if $n > 0xffff;
        return 1;
}

1;
1	dpavlin	24	package M6502;
2
3			use strict;
4			use warnings;
5
6	dpavlin	27	use Data::Dump qw/dump/;
7	dpavlin	29	use Carp qw/confess/;
8	dpavlin	34	use Exporter 'import';
9	dpavlin	96	our @EXPORT = qw'dump_R @mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $debug';
10	dpavlin	208	our $VERSION = '0.0.4';
11	dpavlin	80	require XSLoader;
12			XSLoader::load('M6502', $VERSION);
13	dpavlin	27
14	dpavlin	29	=head1 NAME
15	dpavlin	24
16	dpavlin	54	M6502 - perl bindings for M6502 CPU emulator
17	dpavlin	29
18	dpavlin	89	=head1 FUNCTIONS
19
20	dpavlin	29	=cut
21
22	dpavlin	87	our $debug = 0;
23	dpavlin	24
24	dpavlin	206	our @mem;
25			#@mem = (0xff) x 0x10000; # 64M
26	dpavlin	203	tie @mem, 'M6502::TieMem';
27	dpavlin	29
28	dpavlin	25	# program counter
29	dpavlin	34	our $PC = 0xbeef;
30	dpavlin	25	# CPU registars
31	dpavlin	36	our ( $A, $P, $X, $Y, $S ) = (0) x 5;
32	dpavlin	74
33			our $IPeriod=1; # Set IPeriod to number of CPU cycles between calls to Loop6502
34			our $ICount;
35			our $IRequest; # Set to the INT_IRQ when pending IRQ
36			our $IAutoReset; # Set to 1 to autom. reset IRequest
37			our $TrapBadOps=1; # Set to 1 to warn of illegal opcodes
38			our $Trap; # Set Trap to address to trace from
39			our $Trace; # Set Trace=1 to start tracing
40
41	dpavlin	54	=head2 init
42
43	dpavlin	89	Setup read and write memory hooks (to implement memory mapped devices)
44	dpavlin	26
45	dpavlin	89	$init->(
46			read => sub {
47			return $mem[$_[0]];
48			},
49			write => sub {
50			$mem[$_[0]] = $_[1];
51			},
52			);
53
54	dpavlin	26	=cut
55
56	dpavlin	89	our $_rw_hooks = {
57			read => sub {
58	dpavlin	94	warn sprintf("# callback read(%04x) not implemented\n", @_) if $debug;
59	dpavlin	89	return $mem[$_[0]];
60			},
61			write => sub {
62	dpavlin	92	warn sprintf("# callback write(%04x,%02x) not implemented", @_) if $debug;
63	dpavlin	89	$mem[$_[0]] = $_[1];
64			},
65			};
66
67	dpavlin	26	sub init {
68	dpavlin	33	my $self = shift;
69	dpavlin	89	my $args = {@_};
70			warn "inside init low-level M6502 from ",ref($self),"\n";
71	dpavlin	27
72	dpavlin	89	foreach my $p ( qw/read write/ ) {
73			confess "need $p argument as coderef" unless ( $args->{$p} && ref($args->{$p}) eq 'CODE' );
74			$_rw_hooks->{$p} = $args->{$p};
75			}
76	dpavlin	27
77	dpavlin	89	};
78	dpavlin	27
79	dpavlin	29	=head2 poke_code
80
81	dpavlin	42	Write series of bytes into memory passing through MMU (C<read> and C<write>)
82			functions. If you don't want to trigger MMU, use C<write_chunk>.
83	dpavlin	29
84			$emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
85
86			=cut
87
88			sub poke_code {
89			my $self = shift;
90			my $addr = shift;
91	dpavlin	50	warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
92	dpavlin	51	# call low-level write
93	dpavlin	206	#$_rw_hooks->{write}->( $addr++, $_ ) foreach @_;
94			$mem[$addr++] = $_ foreach @_;
95	dpavlin	29	}
96
97	dpavlin	51	=head2 ram
98
99			Read series of bytes into memory without MMU interaction
100
101			my @code = $emu->ram( 0xc000, 0xc1000 );
102
103			=cut
104
105			sub ram {
106			my $self = shift;
107			my ( $from, $to ) = @_;
108			warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
109	dpavlin	208	# return @mem[ $from .. $to ];
110			return unpack('C*', M6502::mem_peek_region( $from, $to ));
111	dpavlin	51	}
112
113	dpavlin	31	=head2 write_chunk
114
115	dpavlin	42	Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
116
117	dpavlin	31	$emu->write_chunk( $address, $chunk_of_data );
118
119			=cut
120
121			sub write_chunk {
122			my ($self, $addr, $chunk) = @_;
123			my $len = length($chunk);
124			splice @mem, $addr, $len, unpack('C*', $chunk);
125			}
126
127	dpavlin	89	=head1 XS Callbacks
128
129			This functions are called from C<M6502.xs>
130
131			=head2 _read
132
133			Read from memory C callback
134
135			$byte = M6502::_read( $address );
136
137			=cut
138
139			sub _read {
140			return $_rw_hooks->{read}->( @_ );
141			}
142
143			=head2 _write
144
145			Write into memory C callback
146
147			M6502:_write( $address, $byte );
148
149			=cut
150
151			sub _write {
152			return $_rw_hooks->{write}->( @_ );
153			}
154
155	dpavlin	87	=head2 _update_perl_R
156	dpavlin	38
157	dpavlin	87	called by C<M6502.xs> to push changes in registars back to perl variables
158	dpavlin	38
159			=cut
160
161	dpavlin	87	sub _update_perl_R {
162			warn "## M6502::update_perl_R(",dump(@_),")\n" if $debug;
163	dpavlin	74	( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
164	dpavlin	38	dump_R();
165			}
166
167	dpavlin	94	=head1 XS
168
169			Following functions are implemented in C<M6502.xs> and exported to perl.
170
171			=head2 set_debug
172
173			M6502::set_debug( 0 );
174
175			=head2 get_debug
176
177			my $debug = M6502::set_debug();
178
179			=head2 reset
180
181			Reset 6502 CPU, reading PC from C<0xfffc>
182
183			M6502::reset();
184
185			=head2 update_C_R
186
187			Push perl notion of register values to CPU emulator
188
189			M6502::update_C_R();
190
191			=head2 update_perl_R
192
193			Update perl notion of register values
194
195			M6502::update_perl_R();
196
197			=head2 exec
198
199			Execute cpu for specified number of cycles
200
201			my $cycles_left = M6502::exec( $execute_cpu_cycles );
202
203			=head1 Helpers
204
205	dpavlin	38	=head2 dump_R
206
207	dpavlin	68	helper function which dumps registers in humanly readable form
208	dpavlin	38
209	dpavlin	68	my $dump = dump_R;
210
211	dpavlin	38	=cut
212
213			sub dump_R {
214	dpavlin	74	my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x "
215			. "IPeriod:%d ICount:%d IRequest:%02x IAutoReset:%02x TrapBadOps:%d Trap:%d Trace:%d"
216			. "\n",
217			$PC, $A, $P, $X, $Y, $S, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace,
218			);
219	dpavlin	68	warn "## M6502::dump_R $dump" if $debug;
220			return $dump;
221	dpavlin	38	}
222
223	dpavlin	87	=head2 debug
224
225			Turn perl and C-level debugging on/off
226
227			$emu->debug( 0 );
228			$emu->debug( 1 );
229			print $emu->debug;
230
231			=cut
232
233			sub debug {
234			my $self = shift;
235			my $value = shift;
236			if (defined($value)) {
237			$debug = M6502::set_debug($value);
238			} else {
239			$debug = M6502::get_debug();
240			}
241			return $debug;
242			}
243
244	dpavlin	55	=head1 SEE ALSO
245	dpavlin	54
246	dpavlin	55	L<Orao> is sample implementation using this module
247
248	dpavlin	54	=head1 AUTHOR
249
250			Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
251
252			=head1 COPYRIGHT & LICENSE
253
254	dpavlin	203	Copyright 2007-8 Dobrica Pavlinusic, All Rights Reserved.
255	dpavlin	54
256			This program is free software; you can redistribute it and/or modify it
257			under the same terms as Perl itself.
258
259			=cut
260	dpavlin	203
261			package M6502::TieMem;
262
263			use strict;
264			use warnings;
265			use Tie::Array;
266			use base qw(Tie::Array);
267
268			#
269			sub TIEARRAY {
270			my $class = shift;
271			# my $opt = shift;
272			# my $self = { %$opt };
273			my $self = {};
274			bless($self, __PACKAGE__);
275			return $self;
276			}
277
278			sub DESTROY {}
279
280			#
281			sub FETCH {
282			my $self = shift;
283			my $n = shift;
284			my $val = M6502::mem_peek( $n );
285	dpavlin	206	# warn sprintf("FETCH %04x = %02x\n", $n, $val);
286	dpavlin	203	return $val;
287			}
288
289			#
290			sub FETCHSIZE {
291			return 0xffff;
292			}
293
294			#
295			sub STORE {
296			my $self = shift;
297			my $n = shift;
298			my $val = shift;
299			if ( $n > 0xffff ) {
300			warn "over 64k: $n\n";
301			return;
302			}
303			M6502::mem_poke( $n, $val );
304	dpavlin	206	# warn sprintf("STORE %04x <- %02x\n",$n, $val);
305	dpavlin	203	return $val;
306			}
307
308			#
309			sub STORESIZE {
310			die('not allowed (yet)');
311			}
312
313			sub PUSH {
314			die('not allowed (yet)');
315			}
316
317			sub POP {
318			die('not allowed (yet)');
319			}
320
321			sub SHIFT {
322			die('not allowed (yet)');
323			}
324
325			sub UNSHIFT {
326			die('not allowed (yet)');
327			}
328
329			sub DELETE {
330			my $self = shift;
331			my $n = shift;
332			$self->STORE($n, 0);
333			}
334
335			sub EXISTS {
336			my $self = shift;
337			my $n = shift;
338			return 0 if $n > 0xffff;
339			return 1;
340			}
341
342	dpavlin	24	1;