[console] Handle remapping of scancode 86

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>

src/hci/keymap/keymap_pt.c

@@ -29,4 +29,6 @@ struct key_mapping pt_mapping[] __keymap = {
 	{ 0x60, 0x5c },	/* '`' => '\\' */
 	{ 0x7b, 0x2a },	/* '{' => '*' */
 	{ 0x7e, 0x7c },	/* '~' => '|' */
+	{ 0xdc, 0x3c },	/* Pseudo-'\\' => '<' */
+	{ 0xfc, 0x3e },	/* Pseudo-'|' => '>' */
 };