Re: ctrl-x / ctrl-c may not work under GRUB2 with EFI

[Andrey Borzenkov]

В Tue, 06 Aug 2013 10:35:30 +0200
Pawel Wojtalczyk <address@hidden> пишет:

> Hello,
> 
> I run GRUB2 as 64-bit EFI application and I use gfxterm and serial as 
> output.
> 
> I would like to edit commands before boot by type 'e' command. Then I 
> would like to boot by press ctrl-x, but unfortunately the boot does not 
> appears.
> 

Does F10 work?

> The reason is that in AMI and Phoenix BIOSes when ctrl key is pressed 
> then EFI_SIMPLE_TEXT_INPUT_PROTOCOL protocol returns VT100 style 
> encoding of pressed unicode character ( 
> http://www.vt100.net/docs/vt100-ug/table3-5.html).
> 
> I tried to use EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL to get the pressed key 
> modifier (ctrl, alt, etc), but in case when serial console redirection 
> enabled in Phoenix BIOS, none characters are received via serial with 
> EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL(with AMI BIOS characters are received 
> in VT100 encoding style).
> 
> So maybe we can do another way. Maybe we can explicitly set key modifier 
> (as in grub_terminfo_getkey() with 
> http://wiki.phoenix.com/wiki/index.php/Unicode_Control_Characters 
> restrictions) as following:
> 
> --- grub.orig/grub-core/term/efi/console.c      2013-07-31 
> 07:50:52.000000000 +0200
> +++ grub/grub-core/term/efi/console.c   2013-08-06 10:28:26.117499386 +0200
> @@ -125,7 +125,12 @@
>       return GRUB_TERM_NO_KEY;
> 
>     if (key.scan_code == 0)
> -    return key.unicode_char;
> +#if defined (__i386__) || defined (__x86_64__)
> +    if (key.unicode_char < 0x20 && key.unicode_char != 0 && 
> key.unicode_char != '\t' && key.unicode_char != '\b' && key.unicode_char 
> != '\n' && key.unicode_char != '\r')
> +      return GRUB_TERM_CTRL | (key.unicode_char - 1 + 'a');
> +    else
> +#endif /* defined (__i386__) || defined (__x86_64__) */
> +      return key.unicode_char;
>     else if (key.scan_code < ARRAY_SIZE (efi_codes))
>       return efi_codes[key.scan_code];
> 
> In some remote systems EFI serial redirection must be enabled and thus 
> we cannot use serial (as termianl_input) module in GRUB2 and in such 
> case it would be good to allow add support for ctrl-x/ctrl-c under GRUB2 
> via serial console redirection enabled in EFI and attached USB keyboard.
> 
> Regrads
> Pawel Wojtalczyk