Several keyboard layouts define ASCII characters as accessible only
via the AltGr modifier. Add support for this modifier to ensure that
all ASCII characters are accessible.
Experiments suggest that the BIOS console is likely to fail to
generate ASCII characters when the AltGr key is pressed. Work around
this limitation by accepting LShift+RShift (which will definitely
produce an ASCII character) as a synonym for AltGr.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Separate the concept of a keyboard mapping from a list of remapped
keys, to allow for the possibility of supporting multiple keyboard
mappings at runtime.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The key with scancode 86 appears in the position between left shift
and Z on a US keyboard, where it typically fails to exist entirely.
Most US keyboard maps define this nonexistent key as generating "\|",
with the notable exception of "loadkeys" which instead reports it as
generating "<>". Both of these mapping choices duplicate keys that
exist elsewhere in the map, which causes problems for our ASCII-based
remapping mechanism.
Work around these quirks by treating the key as generating "\|" with
the high bit set, and making it subject to remapping. Where the BIOS
generates "\|" as expected, this allows us to remap to the correct
ASCII value.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Rewrite genkeymap.pl in Python with added sanity checks, and update
the list of keyboard mappings to remove those no longer supported by
the underlying "loadkeys" tool.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "us" keyboard layout contains a mapping for keycode 86 (which
seems not to correspond to any physical key on many US keyboards) to
the ASCII character '<'. This mapping causes conflicts with the
mapping for keycode 51, which also maps (with shift) to '<'.
Change the keyboard mapping generator to choose the lowest keycode for
each ASCII character as indicating the relevant mapping to use, on the
basis that a lower keycode roughly indicates a "more normal" key. On
a German keyboard, which has keys for both keycode 51 and keycode 86
present, this causes '<' to be remapped to ';', which is a closer
match to typical user expectations.
Reported-by: Sven Dreyer <sven@dreyer-net.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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>