/[VRac]/M6502/M6502.pm
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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revision 25 by dpavlin, Mon Jul 30 14:02:31 2007 UTC revision 96 by dpavlin, Thu Aug 2 13:58:26 2007 UTC
# Line 3  package M6502; Line 3  package M6502;
3  use strict;  use strict;
4  use warnings;  use warnings;
5    
6  # Dobrica Pavlinusic, <dpavlin@rot13.org> 07/30/07 13:23:19 CEST  use Data::Dump qw/dump/;
7  #  use Carp qw/confess/;
8  # Simple Orao emulation  use Exporter 'import';
9    our @EXPORT = qw'dump_R @mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $debug';
10    our $VERSION = '0.0.2';
11    require XSLoader;
12    XSLoader::load('M6502', $VERSION);
13    
14  my $mem = (0) x 0x10000;        # 64M  =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  # program counter
27  our $PC = 0xbeef;  our $PC = 0xbeef;
28  # CPU registars  # CPU registars
29  our ( $A, $P, $X, $Y, $S ) = (0) x 5;  our ( $A, $P, $X, $Y, $S ) = (0) x 5;
 # Set IPeriod to number of CPU cycles between calls to Loop6502  
 our $IPeriod = 20000;  
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    =head2 init
40    
41    Setup read and write memory hooks (to implement memory mapped devices)
42    
43      $init->(
44            read => sub {
45                    return $mem[$_[0]];
46            },
47            write => sub {
48                    $mem[$_[0]] = $_[1];
49            },
50      );
51    
52    =cut
53    
54    our $_rw_hooks = {
55            read => sub {
56                    warn sprintf("# callback read(%04x) not implemented\n", @_) if $debug;
57                    return $mem[$_[0]];
58            },
59            write => sub {
60                    warn sprintf("# callback write(%04x,%02x) not implemented", @_) if $debug;
61                    $mem[$_[0]] = $_[1];
62            },
63    };
64    
65    sub init {
66            my $self = shift;
67            my $args = {@_};
68            warn "inside init low-level M6502 from ",ref($self),"\n";
69    
70            foreach my $p ( qw/read write/ ) {
71                    confess "need $p argument as coderef" unless ( $args->{$p} && ref($args->{$p}) eq 'CODE' );
72                    $_rw_hooks->{$p} = $args->{$p};
73            }
74    
75    };
76    
77    =head2 poke_code
78    
79    Write series of bytes into memory passing through MMU (C<read> and C<write>)
80    functions. If you don't want to trigger MMU, use C<write_chunk>.
81    
82      $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
83    
84    =cut
85    
86    sub poke_code {
87            my $self = shift;
88            my $addr = shift;
89            warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
90            #$mem[$addr++] = $_ foreach @_;
91            # call low-level write
92            $_rw_hooks->{write}->( $addr++, $_ ) foreach @_;
93    }
94    
95    =head2 ram
96    
97    Read series of bytes into memory without MMU interaction
98    
99      my @code = $emu->ram( 0xc000, 0xc1000 );
100    
101    =cut
102    
103    sub ram {
104            my $self = shift;
105            my ( $from, $to ) = @_;
106            warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
107            return @mem[ $from .. $to ];
108    }
109    
110    =head2 write_chunk
111    
112    Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
113    
114      $emu->write_chunk( $address, $chunk_of_data );
115    
116    =cut
117    
118    sub write_chunk {
119            my ($self, $addr, $chunk) = @_;
120            my $len = length($chunk);
121            splice @mem, $addr, $len, unpack('C*', $chunk);
122    }
123    
124    =head1 XS Callbacks
125    
126    This functions are called from C<M6502.xs>
127    
128    =head2 _read
129    
130    Read from memory C callback
131    
132      $byte = M6502::_read( $address );
133    
134    =cut
135    
136    sub _read {
137            return $_rw_hooks->{read}->( @_ );
138    }
139    
140    =head2 _write
141    
142    Write into memory C callback
143    
144      M6502:_write( $address, $byte );
145    
146    =cut
147    
148    sub _write {
149            return $_rw_hooks->{write}->( @_ );
150    }
151    
152    =head2 _update_perl_R
153    
154    called by C<M6502.xs> to push changes in registars back to perl variables
155    
156    =cut
157    
158    sub _update_perl_R {
159            warn "## M6502::update_perl_R(",dump(@_),")\n" if $debug;
160            ( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
161            dump_R();
162    }
163    
164    =head1 XS
165    
166    Following functions are implemented in C<M6502.xs> and exported to perl.
167    
168    =head2 set_debug
169    
170      M6502::set_debug( 0 );
171    
172    =head2 get_debug
173    
174      my $debug = M6502::set_debug();
175    
176    =head2 reset
177    
178    Reset 6502 CPU, reading PC from C<0xfffc>
179    
180      M6502::reset();
181    
182    =head2 update_C_R
183    
184    Push perl notion of register values to CPU emulator
185    
186      M6502::update_C_R();
187    
188    =head2 update_perl_R
189    
190    Update perl notion of register values
191    
192      M6502::update_perl_R();
193    
194    =head2 exec
195    
196    Execute cpu for specified number of cycles
197    
198      my $cycles_left = M6502::exec( $execute_cpu_cycles );
199    
200    =head1 Helpers
201    
202    =head2 dump_R
203    
204    helper function which dumps registers in humanly readable form
205    
206      my $dump = dump_R;
207    
208    =cut
209    
210    sub dump_R {
211            my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x "
212                    . "IPeriod:%d ICount:%d IRequest:%02x IAutoReset:%02x TrapBadOps:%d Trap:%d Trace:%d"
213                    . "\n",
214                    $PC, $A, $P, $X, $Y, $S, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace,
215            );
216            warn "## M6502::dump_R $dump" if $debug;
217            return $dump;
218    }
219    
220    =head2 debug
221    
222    Turn perl and C-level debugging on/off
223    
224      $emu->debug( 0 );
225      $emu->debug( 1 );
226      print $emu->debug;
227    
228    =cut
229    
230    sub debug {
231            my $self = shift;
232            my $value = shift;
233            if (defined($value)) {
234                    $debug = M6502::set_debug($value);
235            } else {
236                    $debug = M6502::get_debug();
237            }
238            return $debug;
239    }
240    
241    =head1 SEE ALSO
242    
243    L<Orao> is sample implementation using this module
244    
245    =head1 AUTHOR
246    
247    Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
248    
249    =head1 COPYRIGHT & LICENSE
250    
251    Copyright 2007 Dobrica Pavlinusic, All Rights Reserved.
252    
253    This program is free software; you can redistribute it and/or modify it
254    under the same terms as Perl itself.
255    
256    =cut
257  1;  1;
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