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'@mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $run_for $debug';

=head1 NAME

M6502 - perl bindings for M6502 CPU emulator

=cut

my $debug = 0;

our $VERSION = qw(0.0.1);

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;

=head1 FUNCTIONS

=head2 init

Called before C<Run6502>

=cut

sub init {
        my $self = shift;
        warn "inside init low-level M6502 from $self\n";
};

=head2 read

Read from memory

  $byte = read( $address );

=cut

sub read {
        my ($addr) = @_;
        my $byte = $mem[$addr];
        warn "## M6502::read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
        return $byte;
}

=head2 write

Write into emory

  write( $address, $byte );

=cut

sub write {
        warn "## M6502::write(",dump(@_),")\n" if $debug;
        my ($addr,$byte) = @_;
        $mem[$addr] = $byte;
}

=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++] = $_ foreach @_;
        # call low-level write
        Arch::write($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;
}

=head2 push_R

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

=cut

sub push_R {
        warn "## M6502::push_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;
}

=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	74	our @EXPORT = qw'@mem $PC $A $P $X $Y $S $IPeriod $ICount $IRequest $IAutoReset $TrapBadOps $Trap $Trace $run_for $debug';
10	dpavlin	27
11	dpavlin	29	=head1 NAME
12	dpavlin	24
13	dpavlin	54	M6502 - perl bindings for M6502 CPU emulator
14	dpavlin	29
15			=cut
16
17	dpavlin	50	my $debug = 0;
18	dpavlin	24
19	dpavlin	29	our $VERSION = qw(0.0.1);
20	dpavlin	27
21	dpavlin	29	our @mem = (0xff) x 0x10000; # 64M
22
23	dpavlin	25	# program counter
24	dpavlin	34	our $PC = 0xbeef;
25	dpavlin	25	# CPU registars
26	dpavlin	36	our ( $A, $P, $X, $Y, $S ) = (0) x 5;
27	dpavlin	74
28			our $IPeriod=1; # Set IPeriod to number of CPU cycles between calls to Loop6502
29			our $ICount;
30			our $IRequest; # Set to the INT_IRQ when pending IRQ
31			our $IAutoReset; # Set to 1 to autom. reset IRequest
32			our $TrapBadOps=1; # Set to 1 to warn of illegal opcodes
33			our $Trap; # Set Trap to address to trace from
34			our $Trace; # Set Trace=1 to start tracing
35
36	dpavlin	40	# Exec6502 cycles
37	dpavlin	42	our $run_for = 0;
38	dpavlin	24
39	dpavlin	54	=head1 FUNCTIONS
40	dpavlin	26
41	dpavlin	54	=head2 init
42
43	dpavlin	26	Called before C<Run6502>
44
45			=cut
46
47			sub init {
48	dpavlin	33	my $self = shift;
49			warn "inside init low-level M6502 from $self\n";
50	dpavlin	26	};
51	dpavlin	27
52			=head2 read
53
54			Read from memory
55
56			$byte = read( $address );
57
58			=cut
59
60			sub read {
61			my ($addr) = @_;
62			my $byte = $mem[$addr];
63	dpavlin	50	warn "## M6502::read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
64	dpavlin	27	return $byte;
65			}
66
67			=head2 write
68
69			Write into emory
70
71			write( $address, $byte );
72
73			=cut
74
75			sub write {
76	dpavlin	50	warn "## M6502::write(",dump(@_),")\n" if $debug;
77	dpavlin	27	my ($addr,$byte) = @_;
78			$mem[$addr] = $byte;
79			}
80	dpavlin	29
81			=head2 poke_code
82
83	dpavlin	42	Write series of bytes into memory passing through MMU (C<read> and C<write>)
84			functions. If you don't want to trigger MMU, use C<write_chunk>.
85	dpavlin	29
86			$emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
87
88			=cut
89
90			sub poke_code {
91			my $self = shift;
92			my $addr = shift;
93	dpavlin	50	warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
94	dpavlin	42	#$mem[$addr++] = $_ foreach @_;
95	dpavlin	51	# call low-level write
96			Arch::write($addr++, $_) foreach @_;
97	dpavlin	29	}
98
99	dpavlin	51	=head2 ram
100
101			Read series of bytes into memory without MMU interaction
102
103			my @code = $emu->ram( 0xc000, 0xc1000 );
104
105			=cut
106
107			sub ram {
108			my $self = shift;
109			my ( $from, $to ) = @_;
110			warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
111			return @mem[ $from .. $to ];
112			}
113
114	dpavlin	31	=head2 write_chunk
115
116	dpavlin	42	Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
117
118	dpavlin	31	$emu->write_chunk( $address, $chunk_of_data );
119
120			=cut
121
122			sub write_chunk {
123			my ($self, $addr, $chunk) = @_;
124			my $len = length($chunk);
125			splice @mem, $addr, $len, unpack('C*', $chunk);
126			}
127
128	dpavlin	42	=head2 prompt
129
130			Call this after C<< $run_for >> cycles have been run on processor
131
132			=cut
133
134			sub prompt {
135			warn "prompt -- you should override this\n";
136			return 1;
137			}
138
139	dpavlin	38	=head2 push_R
140
141			called by C<perl.c> to push changes in registars back to perl variables
142
143			=cut
144
145			sub push_R {
146	dpavlin	50	warn "## M6502::push_R(",dump(@_),")\n" if $debug;
147	dpavlin	74	( $A, $P, $X, $Y, $S, $PC, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace ) = @_;
148	dpavlin	38	dump_R();
149			}
150
151			=head2 dump_R
152
153	dpavlin	68	helper function which dumps registers in humanly readable form
154	dpavlin	38
155	dpavlin	68	my $dump = dump_R;
156
157	dpavlin	38	=cut
158
159			sub dump_R {
160	dpavlin	74	my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x "
161			. "IPeriod:%d ICount:%d IRequest:%02x IAutoReset:%02x TrapBadOps:%d Trap:%d Trace:%d"
162			. "\n",
163			$PC, $A, $P, $X, $Y, $S, $IPeriod, $ICount, $IRequest, $IAutoReset, $TrapBadOps, $Trap, $Trace,
164			);
165	dpavlin	68	warn "## M6502::dump_R $dump" if $debug;
166			return $dump;
167	dpavlin	38	}
168
169	dpavlin	55	=head1 SEE ALSO
170	dpavlin	54
171	dpavlin	55	L<Orao> is sample implementation using this module
172
173	dpavlin	54	=head1 AUTHOR
174
175			Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
176
177			=head1 COPYRIGHT & LICENSE
178
179			Copyright 2007 Dobrica Pavlinusic, All Rights Reserved.
180
181			This program is free software; you can redistribute it and/or modify it
182			under the same terms as Perl itself.
183
184			=cut
185	dpavlin	24	1;