Re: [PATCH v2] drivers/video: Convert source files to UTF-8

[Frediano Ziglio <frediano.ziglio@xxxxxxxxx>]

On Thu, Sep 26, 2024 at 3:46 PM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> On 26.09.2024 15:48, Frediano Ziglio wrote:
> > --- a/xen/drivers/video/font_8x14.c
> > +++ b/xen/drivers/video/font_8x14.c
> > @@ -2059,7 +2059,7 @@ static const unsigned char fontdata_8x14[FONTDATAMAX] 
> > = {
> >      0x00, /* 00000000 */
> >      0x00, /* 00000000 */
> >
> > -    /* 128 0x80 'Ÿˆ */
> > +    /* 128 0x80 'Ÿˆ */
>
> I'm unconvinced this representation is any better. The data that follows
> right here clearly means 'Ç', not 'Ÿ'. Which is U+00c7, not U+0080. I
> don't have my Unicode manual to hand, but I seem to vaguely recall that
> U+0080 doesn't really have a glyph associated with it.
>
> Of course I'm also uncertain whether my mail UI actually correctly decoded
> the transfer encoding (base64) that you now used. In any event I'm unsure
> of associating the upper 128 code points with any particular characters
> (glyphs). We don't render UTF-8 to the console, and what those code points
> mean is unknown until code page information is provided. I see the
> following options:
> 1) The glyphs represent what the bit patterns encode, encoded as UTF-8.

That was what I was trying to do.
I wrongly thought it was latin1, in reality looking at the font (why
not?) it's code page 437, so this commit is doing the right thing
https://gitlab.com/xen-project/people/fziglio/xen/-/commit/7ca512e8ae21bb02339ed7a1a78409827a08aea4.
Now... I'm trying to send the patch to the mailing list, which seems
easy, but I have to find the right combination of options, tools get
very easily confused about (that's why I send the link of the commit,
at least people can take a look and see that is correct)

> 2) The glyphs are simply omitted for the upper half of the range.
> 3) We purge any encoding of particular glyphs for the upper half of the
>    range and instead expand the upper 128 entries to some placeholders
>    when rendering (like e.g. the Windows font I'm looking at, using a
>    boxed question mark).
>
> Jan

Trying to get the right email without spamming the ML.

Frediano