EFI: setkey not working for SHIFT+key combinations on some UEFI implementations

Some UEFI implementations return every SHIFT+key combination with bit 24 set, therefore setkey is not working for this keys. E.g. the uppercase Q returns 0x1000051 instead of 0x0051, the uppercase A returns 0x1000041 instead of 0x0041 and so on. This happens with all SHIFT+key combinations I've tested.

I cleared bit 24 by changing

grub4dos/stage2/builtins.c

Line 11234 in 2b155c9

if (ascii_key_map[i].from_code == key)

to
if (ascii_key_map[i].from_code == (key &= ~(1<<(24))))

Then setkey is working as expected.

I however did not investigate further to understand the function of this bit. If it just stands for the SHIFT key then clearing the bit might be a possible solution.

int
remap_ascii_char (int key)
{
int i;

if ((key & 0x1000000) && (key & 0xffffff) < 0x7b)
key = key & 0xff;
for (i=0; ascii_key_map[i].from_code; i++)
{
if (ascii_key_map[i].from_code == key)
return (ascii_key_map[i].to_code);
}
return key;
}

have a try
BOOTX64.rar.txt

It's close but some keys are still not working:

0x100007b which should be 0x007b,
0x100007c which should be 0x007c,
0x100007d which should be 0x007d,
0x100007e which should be 0x007e.

I hope I did not miss any.

BOOTX64.rar.txt

It works, thanks!