rockbox/tools/ovl_offset.pl
Frank Gevaerts f3fd2d41cc Make overlay plugins work again.
Overlay plugins got broken because ovl_offset.pl assumes the audio buffer
ends where the plugin buffer starts. Buflib however keeps its handle table
there, so there are a few hundred bytes fewer available, so loading the
overlay fails. We work around this by linking the overlay at a slightly
lower address (1024 bytes lower). If the handle table ever grows more than
that, overlays will start failing again and we either need a different
solution or increase the margin a bit.

Change-Id: Id98cb52da2c8c4a4bc773362a46f646774112f85
2012-05-19 18:53:17 +02:00

35 lines
1.1 KiB
Perl
Executable file

#!/usr/bin/perl
# Calculate the highest possible location for an overlay based
# on a reference map file (.refmap)
sub map_scan {
# The buflib handle table is a few hundred bytes, just before
# the plugin buffer. We assume it's never more than 1024 bytes.
# If this assumption is wrong, overlay loading will fail.
my $max_handle_table_size = 1024;
my ($map) = @_;
my $ramstart = -1, $ramsize = -1, $startaddr = -1, $endaddr = -1;
open (MAP, "<$map");
while (<MAP>) {
if ($_ =~ /^PLUGIN_RAM +0x([0-9a-f]+) +0x([0-9a-f]+)$/) {
$ramstart = hex($1);
$ramsize = hex($2);
}
elsif ($_ =~ / +0x([0-9a-f]+) +_?plugin_start_addr = ./) {
$startaddr = hex($1);
}
elsif ($_ =~ / +0x([0-9a-f]+) +_?plugin_end_addr = ./) {
$endaddr = hex($1);
}
}
close (MAP);
if ($ramstart < 0 || $ramsize < 0 || $startaddr < 0 || $endaddr < 0
|| $ramstart != $startaddr) {
printf "Could not analyze map file.\n";
exit 1;
}
return $ramstart + $ramsize - $endaddr - $max_handle_table_size;
}
printf map_scan($ARGV[0]) & ~0xf;