[plex86] Little perl scripts

[James Mastros]

Here's two little perl scripts for misc/.  Both are worksforme quality, but
I don't see why they shouldn't workforyou.

mount_image.pl will, given arguments of mountpoint image partitionnumber,
mount the given partition.  It's very sensitive to the output format of 
fdisk --
it's correct for fdisk v2.10o; run fdisk -v (little v!) for your version 
number.
It assumes that you are root and that /dev/loop0 is free.
Requires a linuxish fdisk, mount, and losetup.

freqcount_top.pl will parse the freqcounts file, and give the top 22 
most-emulated
opcodes, including dissassembley.  Note that the disasm isn't all that good.
Requires a gnuish as and objdump.

   -=- James Mastros

#!/usr/bin/perl -w
use strict;

# These parameters are correct for fdisk v2.10o
my $BLOCKSIZELINE=2;  # The line number of the "Units = sectors of $ bytes"
my $PARTOFFSETLINE=4; # The line number where partition 0 would be (if there were a 
partition 0)

# Get args: mount_image.pl mountpoint imagefile partationnumb.
# Partition number as linux uses.
my $mountpoint = shift or die "First argument should be mountpoint";
my $image = shift or die "Second argument should be image";
my $part = shift || 1;

my @fdisk = `fdisk -ul $image 2>/dev/null`;
my $blocksize  = (split " ", $fdisk[$BLOCKSIZELINE])[6];
my $startblock = (split " ", $fdisk[$PARTOFFSETLINE+$part])[2];

print "blocksize: $blocksize startblock: $startblock\n";
system('losetup', '-o', $startblock*$blocksize, '/dev/loop0', $image);
exec('mount', '/dev/loop0', $mountpoint);

#!/usr/bin/perl -w

use strict;

sub sortdex {
        my @in = @{+shift};
        my @double;
        my $i;
        
        for $i (0 .. scalar(@in)-1) {
                $double[$i]=sprintf("%8.8x %4.4x", $in[$i], $i);
        #       print $double[$i], "\n";
        #       $double[$i][0]=$in[$i];
        #       $double[$i][1]=$i;
        }
        
        # Decresing order
        @double = sort {$b cmp $a} @double;
        
        return \@double;
}

sub disasm {
        use IO::File;
        
        my $opcode = shift;
        my $asmfile = new IO::File "/tmp/freqcount_top.pl-opcode.s", 
O_WRONLY|O_CREAT|O_TRUNC or die "$! while opening /tmp/freqcount_top.pl-opcode.s";
        local $/="\n";
        
        print $asmfile <<"__END__";
.text
.global main
main:
        .byte 0x$opcode

__END__
        undef $asmfile;
        
        chdir '/tmp';
        `as /tmp/freqcount_top.pl-opcode.s -o /tmp/freqcount_top.pl-opcode.o`;
        my @objdump = `objdump -D -w --start-address=0 --stop-address=1 
/tmp/freqcount_top.pl-opcode.o`;
        
        # my $i;
        # foreach (@objdump) {
        #       $i++;
        #       print "$i: $_";
        # };
        
        # NOTE: very touchy on format of objdump output!
        @objdump = split " ", $objdump[6];
        
        return join " ", @objdump[2..$#objdump];
}

my(@freq, $filename, $fh);

use IO::File;

$filename = shift || 'freqcounts';
$fh = new IO::File "<$filename" or die "Opening $filename: $!";

{
        local $/ = undef;
        @freq = unpack("l*", <$fh>);
}

if (scalar(@freq)!=0x1ff) {
        print "Odd, freqcount isn't of 0x1ff instructions (0x", scalar @freq, ")\n";
}

@freq = @{sortdex \@freq};

my $i;
for $i (0..23) {
        my ($count, $opcode) = (split ' ', $freq[$i]);
        # print disasm $opcode;
        printf "%2d: 0x%s = %s with %d incovations\n", $i+1, $opcode, disasm($opcode), 
hex $count;
}