Re: [PATCH 7/8] efi_selftest: Add box drawing character selftest

[Andre Przywara <andre.przywara@arm.com>]

On Mon, 10 Jan 2022 10:23:20 +0100
Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:

Hi Heinrich,

> On 1/10/22 01:56, Andre Przywara wrote:
> > UEFI applications rely on Unicode output capability, and might use that
> > for drawing pseudo-graphical interfaces using Unicode defined box
> > drawing characters.
> > 
> > Add a simple test to display the most basic box characters, which would
> > need to be checked manually on the screen for correctness.
> > To facilitate this, add a three second delay after the output at this
> > point.
> > 
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >   lib/efi_selftest/efi_selftest_textoutput.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> > 
> > diff --git a/lib/efi_selftest/efi_selftest_textoutput.c b/lib/efi_selftest/efi_selftest_textoutput.c
> > index a437732496b..1542c187de7 100644
> > --- a/lib/efi_selftest/efi_selftest_textoutput.c
> > +++ b/lib/efi_selftest/efi_selftest_textoutput.c
> > @@ -123,6 +123,17 @@ static int execute(void)
> >   		efi_st_error("OutputString failed for international chars\n");
> >   		return EFI_ST_FAILURE;
> >   	}
> > +	ret  = con_out->output_string(con_out, L"┌─┬─┐\n");
> > +	ret |= con_out->output_string(con_out, L"│ │ │\n");
> > +	ret |= con_out->output_string(con_out, L"├─┼─┤\n");
> > +	ret |= con_out->output_string(con_out, L"│ │ │\n");
> > +	ret |= con_out->output_string(con_out, L"└─┴─┘\n");  
> 
> %s/L"/u"/
> 
> Unicode characters in code are not supported by all tools. The 
> interpretation may further depend on the users locale. Please, use \u 
> escape sequences. A single output_string() call is enough. A notice for 
> the user might be helpful. So I suggest:
> 
> This should render as four boxes with text
> ┌─────────────┬───────────────┐
> │ left top    │ right top     │
> ├─────────────┼───────────────┤
> │ left bottom │ right bottom  │
> └─────────────┴───────────────┘
> 
> const u16 text[] =
> u"This should render as four boxes with text\n"
> u"\u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500"
> u"\u2500\u2500\u2500\u252c\u2500\u2500\u2500\u2500\u2500\u2500\u2500"
> u"\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\n\u2502"
> u" left top    \u2502 right top     \u2502\n\u251c\u2500"
> u"\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500"
> u"\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500"
> u"\u2500\u2500\u2500\u2500\u2500\u2500\u2524\n\u2502 "
> u"left bottom \u2502 right bottom  \u2502\n\u2514\u2500\u2500\u2500"
> u"\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2534"
> u"\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500"
> u"\u2500\u2500\u2500\u2500\u2518\n";

Ha, very good, thanks for the hints! And for typing all those numbers!
I was wondering about UTF-8 in source, but since my ancient Slackware could
deal with it, I deemed it safe ;-)

Will fix it accordingly!

Cheers,
Andre

> > +	if (ret != EFI_ST_SUCCESS) {
> > +		efi_st_error("OutputString failed for box drawing chars\n");
> > +		return EFI_ST_FAILURE;
> > +	}
> > +	con_out->output_string(con_out, L"waiting for admiration...\n");
> > +	EFI_CALL(systab.boottime->stall(3000000));
> >   	efi_st_printf("\n");
> >   
> >   	return EFI_ST_SUCCESS;  
>