[console] Add keymap generator

Inspired by LILO's keytab-lilo.pl, genkeymap.pl uses "loadkeys -b" to
obtain a Linux keyboard map, and generates a file keymap_xx.c in
hci/keymap.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 224 insertions, 0 deletions

diff --git a/src/util/genkeymap.pl b/src/util/genkeymap.pl
new file mode 100755
index 00000000..89f14695
--- /dev/null
+++ b/src/util/genkeymap.pl
@@ -0,0 +1,224 @@
+#!/usr/bin/perl -w
+#
+# Copyright (C) 2011 Michael Brown <mbrown@fensystems.co.uk>.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of the
+# License, or any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+=head1 NAME
+
+genkeymap.pl
+
+=head1 SYNOPSIS
+
+genkeymap.pl [options] <keymap name>
+
+Options:
+
+    -f,--from=<name>	Set BIOS keymap name (default "us")
+    -h,--help		Display brief help message
+    -v,--verbose	Increase verbosity
+    -q,--quiet		Decrease verbosity
+
+=cut
+
+# With reference to:
+#
+# http://gunnarwrobel.de/wiki/Linux-and-the-keyboard.html
+
+use Getopt::Long;
+use Pod::Usage;
+use strict;
+use warnings;
+
+use constant BIOS_KEYMAP => "us";
+use constant BKEYMAP_MAGIC => "bkeymap";
+use constant MAX_NR_KEYMAPS => 256;
+use constant NR_KEYS => 128;
+use constant KG_SHIFT => 0;
+use constant KG_ALTGR => 1;
+use constant KG_CTRL => 2;
+use constant KG_ALT => 3;
+use constant KG_SHIFTL => 4;
+use constant KG_KANASHIFT => 4;
+use constant KG_SHIFTR => 5;
+use constant KG_CTRLL => 6;
+use constant KG_CTRLR => 7;
+use constant KG_CAPSSHIFT => 8;
+use constant KT_LATIN => 0;
+use constant KT_FN => 1;
+use constant KT_SPEC => 2;
+use constant KT_PAD => 3;
+use constant KT_DEAD => 4;
+use constant KT_CONS => 5;
+use constant KT_CUR => 6;
+use constant KT_SHIFT => 7;
+use constant KT_META => 8;
+use constant KT_ASCII => 9;
+use constant KT_LOCK => 10;
+use constant KT_LETTER => 11;
+use constant KT_SLOCK => 12;
+use constant KT_SPKUP => 14;
+
+my $verbosity = 1;
+my $from_name = BIOS_KEYMAP;
+
+# Read named keymaps using "loadkeys -b"
+#
+sub read_keymaps {
+  my $name = shift;
+  my $keymaps = [];
+
+  # Generate binary keymap
+  open my $pipe, "-|", "loadkeys", "-b", $name
+      or die "Could not load keymap \"".$name."\": $!\n";
+
+  # Check magic
+  read $pipe, my $magic, length BKEYMAP_MAGIC
+      or die "Could not read from \"".$name."\": $!\n";
+  die "Bad magic value from \"".$name."\"\n"
+      unless $magic eq BKEYMAP_MAGIC;
+
+  # Read list of included keymaps
+  read $pipe, my $included, MAX_NR_KEYMAPS
+      or die "Could not read from \"".$name."\": $!\n";
+  my @included = unpack ( "C*", $included );
+  die "Missing or truncated keymap list from \"".$name."\"\n"
+      unless @included == MAX_NR_KEYMAPS;
+
+  # Read each keymap in turn
+  for ( my $keymap = 0 ; $keymap < MAX_NR_KEYMAPS ; $keymap++ ) {
+    if ( $included[$keymap] ) {
+      read $pipe, my $keysyms, ( NR_KEYS * 2 )
+	  or die "Could not read from \"".$name."\": $!\n";
+      my @keysyms = unpack ( "S*", $keysyms );
+      die "Missing or truncated keymap ".$keymap." from \"".$name."\"\n"
+	  unless @keysyms == NR_KEYS;
+      push @$keymaps, \@keysyms;
+    } else {
+      push @$keymaps, undef;
+    }
+  }
+
+  close $pipe;
+  return $keymaps;
+}
+
+# Translate keysym value to ASCII
+#
+sub keysym_to_ascii {
+  my $keysym = shift;
+
+  # Non-existent keysyms have no ASCII equivalent
+  return unless $keysym;
+
+  # Sanity check
+  die "Unexpected keysym ".sprintf ( "0x%04x\n", $keysym )."\n"
+      if $keysym & 0xf000;
+
+  # Extract type and value
+  my $type = ( $keysym >> 8 );
+  my $value = ( $keysym & 0xff );
+
+  # Non-simple types have no ASCII equivalent
+  return unless ( ( $type == KT_LATIN ) || ( $type == KT_ASCII ) ||
+		  ( $type == KT_LETTER ) );
+
+  # High-bit-set characters cannot be generated on a US keyboard
+  return if $value & 0x80;
+
+  return $value;
+}
+
+# Translate ASCII to descriptive name
+#
+sub ascii_to_name {
+  my $ascii = shift;
+
+  if ( $ascii == 0x5c ) {
+    return "'\\\\'";
+  } elsif ( $ascii == 0x27 ) {
+    return "'\\\''";
+  } elsif ( ( $ascii >= 0x20 ) && ( $ascii <= 0x7e ) ) {
+    return sprintf ( "'%c'", $ascii );
+  } elsif ( $ascii <= 0x1a ) {
+    return sprintf ( "Ctrl-%c", ( 0x40 + $ascii ) );
+  } else {
+    return sprintf ( "0x%02x", $ascii );
+  }
+}
+
+# Produce translation table between two keymaps
+#
+sub translate_keymaps {
+  my $from = shift;
+  my $to = shift;
+  my $map = {};
+
+  foreach my $keymap ( 0, 1 << KG_SHIFT, 1 << KG_CTRL ) {
+    for ( my $keycode = 0 ; $keycode < NR_KEYS ; $keycode++ ) {
+      my $from_ascii = keysym_to_ascii ( $from->[$keymap]->[$keycode] )
+	  or next;
+      my $to_ascii = keysym_to_ascii ( $to->[$keymap]->[$keycode] )
+	  or next;
+      if ( ( $from_ascii != $to_ascii ) && $verbosity > 1 ) {
+	printf STDERR "In keymap %d: %s => %s%s\n", $keymap,
+	       ascii_to_name ( $from_ascii ), ascii_to_name ( $to_ascii ),
+	       ( $map->{$from_ascii} ? " (ignored)" : "" );
+      }
+      $map->{$from_ascii} ||= $to_ascii;
+    }
+  }
+  return $map;
+}
+
+# Parse command-line options
+Getopt::Long::Configure ( 'bundling', 'auto_abbrev' );
+GetOptions (
+  'verbose|v+' => sub { $verbosity++; },
+  'quiet|q+' => sub { $verbosity--; },
+  'from|f=s' => sub { shift; $from_name = shift; },
+  'help|h' => sub { pod2usage ( 1 ); },
+) or die "Could not parse command-line options\n";
+pod2usage ( 1 ) unless @ARGV == 1;
+my $to_name = shift;
+
+# Read and translate keymaps
+my $from = read_keymaps ( $from_name );
+my $to = read_keymaps ( $to_name );
+my $map = translate_keymaps ( $from, $to );
+
+# Generate output
+( my $to_name_c = $to_name ) =~ s/\W/_/g;
+printf "/** \@file\n";
+printf " *\n";
+printf " * \"".$to_name."\" keyboard mapping\n";
+printf " *\n";
+printf " * This file is automatically generated; do not edit\n";
+printf " *\n";
+printf " */\n";
+printf "\n";
+printf "FILE_LICENCE ( PUBLIC_DOMAIN );\n";
+printf "\n";
+printf "#include <ipxe/keymap.h>\n";
+printf "\n";
+printf "/** \"".$to_name."\" keyboard mapping */\n";
+printf "struct key_mapping ".$to_name_c."_mapping[] __keymap = {\n";
+foreach my $from_sym ( sort { $a <=> $b } keys %$map ) {
+  my $to_sym = $map->{$from_sym};
+  next if $from_sym == $to_sym;
+  printf "\t{ 0x%02x, 0x%02x },\t/* %s => %s */\n", $from_sym, $to_sym,
+	 ascii_to_name ( $from_sym ), ascii_to_name ( $to_sym );
+}
+printf "};\n";