/[VRac]/M6502/M6502.pm
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Contents of /M6502/M6502.pm

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Revision 90 - (show annotations)
Thu Aug 2 12:23:18 2007 UTC (12 years, 11 months ago) by dpavlin
File size: 4455 byte(s)
minor tweaks, everything tested now works
1 package M6502;
2
3 use strict;
4 use warnings;
5
6 use Data::Dump qw/dump/;
7 use Carp qw/confess/;
8 use Exporter 'import';
9 our @EXPORT = qw'dump_R @mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $run_for $debug';
10 our $VERSION = '0.0.2';
11 require XSLoader;
12 XSLoader::load('M6502', $VERSION);
13
14 =head1 NAME
15
16 M6502 - perl bindings for M6502 CPU emulator
17
18 =head1 FUNCTIONS
19
20 =cut
21
22 our $debug = 0;
23
24 our @mem = (0xff) x 0x10000; # 64M
25
26 # program counter
27 our $PC = 0xbeef;
28 # CPU registars
29 our ( $A, $P, $X, $Y, $S ) = (0) x 5;
30
31 our $IPeriod=1; # Set IPeriod to number of CPU cycles between calls to Loop6502
32 our $ICount;
33 our $IRequest; # Set to the INT_IRQ when pending IRQ
34 our $IAutoReset; # Set to 1 to autom. reset IRequest
35 our $TrapBadOps=1; # Set to 1 to warn of illegal opcodes
36 our $Trap; # Set Trap to address to trace from
37 our $Trace; # Set Trace=1 to start tracing
38
39 # Exec6502 cycles
40 our $run_for = 0;
41
42 =head2 init
43
44 Setup read and write memory hooks (to implement memory mapped devices)
45
46 $init->(
47 read => sub {
48 return $mem[$_[0]];
49 },
50 write => sub {
51 $mem[$_[0]] = $_[1];
52 },
53 );
54
55 =cut
56
57 our $_rw_hooks = {
58 read => sub {
59 return $mem[$_[0]];
60 },
61 write => sub {
62 $mem[$_[0]] = $_[1];
63 },
64 };
65
66 sub init {
67 my $self = shift;
68 my $args = {@_};
69 warn "inside init low-level M6502 from ",ref($self),"\n";
70
71 foreach my $p ( qw/read write/ ) {
72 confess "need $p argument as coderef" unless ( $args->{$p} && ref($args->{$p}) eq 'CODE' );
73 $_rw_hooks->{$p} = $args->{$p};
74 }
75
76 };
77
78 =head2 poke_code
79
80 Write series of bytes into memory passing through MMU (C<read> and C<write>)
81 functions. If you don't want to trigger MMU, use C<write_chunk>.
82
83 $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
84
85 =cut
86
87 sub poke_code {
88 my $self = shift;
89 my $addr = shift;
90 warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
91 #$mem[$addr++] = $_ foreach @_;
92 # call low-level write
93 $_rw_hooks->{write}->( $addr++, $_ ) foreach @_;
94 }
95
96 =head2 ram
97
98 Read series of bytes into memory without MMU interaction
99
100 my @code = $emu->ram( 0xc000, 0xc1000 );
101
102 =cut
103
104 sub ram {
105 my $self = shift;
106 my ( $from, $to ) = @_;
107 warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
108 return @mem[ $from .. $to ];
109 }
110
111 =head2 write_chunk
112
113 Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
114
115 $emu->write_chunk( $address, $chunk_of_data );
116
117 =cut
118
119 sub write_chunk {
120 my ($self, $addr, $chunk) = @_;
121 my $len = length($chunk);
122 splice @mem, $addr, $len, unpack('C*', $chunk);
123 }
124
125 =head2 prompt
126
127 Call this after C<< $run_for >> cycles have been run on processor
128
129 =cut
130
131 sub prompt {
132 warn "prompt -- you should override this\n";
133 return 1;
134 }
135
136 =head1 XS Callbacks
137
138 This functions are called from C<M6502.xs>
139
140 =head2 _read
141
142 Read from memory C callback
143
144 $byte = M6502::_read( $address );
145
146 =cut
147
148 sub _read {
149 return $_rw_hooks->{read}->( @_ );
150 }
151
152 =head2 _write
153
154 Write into memory C callback
155
156 M6502:_write( $address, $byte );
157
158 =cut
159
160 sub _write {
161 return $_rw_hooks->{write}->( @_ );
162 }
163
164 =head2 _update_perl_R
165
166 called by C<M6502.xs> to push changes in registars back to perl variables
167
168 =cut
169
170 sub _update_perl_R {
171 warn "## M6502::update_perl_R(",dump(@_),")\n" if $debug;
172 ( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
173 dump_R();
174 }
175
176 =head2 dump_R
177
178 helper function which dumps registers in humanly readable form
179
180 my $dump = dump_R;
181
182 =cut
183
184 sub dump_R {
185 my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x "
186 . "IPeriod:%d ICount:%d IRequest:%02x IAutoReset:%02x TrapBadOps:%d Trap:%d Trace:%d"
187 . "\n",
188 $PC, $A, $P, $X, $Y, $S, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace,
189 );
190 warn "## M6502::dump_R $dump" if $debug;
191 return $dump;
192 }
193
194 =head2 debug
195
196 Turn perl and C-level debugging on/off
197
198 $emu->debug( 0 );
199 $emu->debug( 1 );
200 print $emu->debug;
201
202 =cut
203
204 sub debug {
205 my $self = shift;
206 my $value = shift;
207 if (defined($value)) {
208 $debug = M6502::set_debug($value);
209 } else {
210 $debug = M6502::get_debug();
211 }
212 return $debug;
213 }
214
215 =head1 SEE ALSO
216
217 L<Orao> is sample implementation using this module
218
219 =head1 AUTHOR
220
221 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
222
223 =head1 COPYRIGHT & LICENSE
224
225 Copyright 2007 Dobrica Pavlinusic, All Rights Reserved.
226
227 This program is free software; you can redistribute it and/or modify it
228 under the same terms as Perl itself.
229
230 =cut
231 1;

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