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 $run_for $debug';
our $VERSION = '0.0.2';
require XSLoader;
XSLoader::load('M6502', $VERSION);

=head1 NAME

M6502 - perl bindings for M6502 CPU emulator

=head1 FUNCTIONS

=cut

our $debug = 0;

our @mem = (0xff) x 0x10000;    # 64M

# 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

# Exec6502 cycles
our $run_for = 0;

=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 {
                return $mem[$_[0]];
        },
        write => sub {
                $mem[$_[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 $self->debug;
        #$mem[$addr++] = $_ foreach @_;
        # call low-level write
        $_rw_hooks->{write}->( $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 ];
}

=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);
}

=head2 prompt

Call this after C<< $run_for >> cycles have been run on processor

=cut

sub prompt {
        warn "prompt -- you should override this\n";
        return 1;
}

=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();
}

=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 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
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	86	our @EXPORT = qw'dump_R @mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $run_for $debug';
10	dpavlin	80	our $VERSION = '0.0.2';
11			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	29	our @mem = (0xff) x 0x10000; # 64M
25
26	dpavlin	25	# program counter
27	dpavlin	34	our $PC = 0xbeef;
28	dpavlin	25	# CPU registars
29	dpavlin	36	our ( $A, $P, $X, $Y, $S ) = (0) x 5;
30	dpavlin	74
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	dpavlin	40	# Exec6502 cycles
40	dpavlin	42	our $run_for = 0;
41	dpavlin	24
42	dpavlin	54	=head2 init
43
44	dpavlin	89	Setup read and write memory hooks (to implement memory mapped devices)
45	dpavlin	26
46	dpavlin	89	$init->(
47			read => sub {
48			return $mem[$_[0]];
49			},
50			write => sub {
51			$mem[$_[0]] = $_[1];
52			},
53			);
54
55	dpavlin	26	=cut
56
57	dpavlin	89	our $_rw_hooks = {
58			read => sub {
59			return $mem[$_[0]];
60			},
61			write => sub {
62			$mem[$_[0]] = $_[1];
63			},
64			};
65
66	dpavlin	26	sub init {
67	dpavlin	33	my $self = shift;
68	dpavlin	89	my $args = {@_};
69			warn "inside init low-level M6502 from ",ref($self),"\n";
70	dpavlin	27
71	dpavlin	89	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	dpavlin	27
76	dpavlin	89	};
77	dpavlin	27
78	dpavlin	29	=head2 poke_code
79
80	dpavlin	42	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	dpavlin	29
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	dpavlin	50	warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
91	dpavlin	42	#$mem[$addr++] = $_ foreach @_;
92	dpavlin	51	# call low-level write
93	dpavlin	90	$_rw_hooks->{write}->( $addr++, $_ ) foreach @_;
94	dpavlin	29	}
95
96	dpavlin	51	=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	dpavlin	31	=head2 write_chunk
112
113	dpavlin	42	Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
114
115	dpavlin	31	$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	dpavlin	42	=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	dpavlin	89	=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	dpavlin	87	=head2 _update_perl_R
165	dpavlin	38
166	dpavlin	87	called by C<M6502.xs> to push changes in registars back to perl variables
167	dpavlin	38
168			=cut
169
170	dpavlin	87	sub _update_perl_R {
171			warn "## M6502::update_perl_R(",dump(@_),")\n" if $debug;
172	dpavlin	74	( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
173	dpavlin	38	dump_R();
174			}
175
176			=head2 dump_R
177
178	dpavlin	68	helper function which dumps registers in humanly readable form
179	dpavlin	38
180	dpavlin	68	my $dump = dump_R;
181
182	dpavlin	38	=cut
183
184			sub dump_R {
185	dpavlin	74	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	dpavlin	68	warn "## M6502::dump_R $dump" if $debug;
191			return $dump;
192	dpavlin	38	}
193
194	dpavlin	87	=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	dpavlin	55	=head1 SEE ALSO
216	dpavlin	54
217	dpavlin	55	L<Orao> is sample implementation using this module
218
219	dpavlin	54	=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	dpavlin	24	1;