Re: [edk2-devel] Need clarification about UEFI Strings

["Ayush Singh" <ayushdevel1325@gmail.com>]

Just for clarification, UCS2 and not UTF-16 means there are no
surrogate pairs right?

Ayush Singh

On Tue, Jun 7, 2022 at 5:15 PM Ayush Singh via groups.io
<ayushdevel1325=gmail.com@groups.io> wrote:
>
> Ok, Thanks for all the help.
>
> On Tue, Jun 7, 2022 at 3:28 PM Pedro Falcato <pedro.falcato@gmail.com> wrote:
> >
> > I'd say that it depends. But 98% of the strings you'll find in UEFI (including APIs) are UCS-2 CHAR16 strings.
> >
> > On Tue, Jun 7, 2022 at 9:19 AM Ayush Singh <ayushdevel1325@gmail.com> wrote:
> >>
> >> Thanks, Pedro,
> >>
> >> However, according to the specs, it is possible to construct ASCII
> >> Strings as well. So when would ASCII Strings be used over normal UCS-2
> >> Strings?
> >>
> >> Ayush Singh
> >>
> >> On Tue, Jun 7, 2022 at 1:13 PM Pedro Falcato <pedro.falcato@gmail.com> wrote:
> >> >
> >> > Hi Ayush,
> >> >
> >> > In the latest UEFI 2.9 spec, it's specified under 2.3.1 that CHAR8 strings/characters are (usually) ASCII, and CHAR16 strings/characters are (usually) UCS-2 (*not* UTF-16).
> >> >
> >> > On Tue, Jun 7, 2022 at 7:02 AM Ayush Singh <ayushdevel1325@gmail.com> wrote:
> >> >>
> >> >> Hello everyone, I am trying to write an implementation for UEFI
> >> >> strings in Rust and just wanted clarification about some things.
> >> >>
> >> >> Are UEFI Strings UTF-16 encoded? I have looked at some previous Rust
> >> >> implementations for this and it seems UEFI does not support the whole
> >> >> UTF-16 but rather only UCS-2
> >> >> (https://en.wikipedia.org/wiki/Universal_Coded_Character_Set) which is
> >> >> a subset of UTF-16.
> >> >>
> >> >> There is also something called WTF-8
> >> >> (https://en.wikipedia.org/wiki/UTF-8#WTF-8) which Rust uses to
> >> >> represent OsStrings in Windows which is supposed to use UTF-16 (?).
> >> >>
> >> >> Anyway, if someone can point me to the resources/specifications of
> >> >> UEFI Strings, it would be a great help.
> >> >>
> >> >> Ayush Singh
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >> > --
> >> > Pedro Falcato
> >
> >
> >
> > --
> > Pedro Falcato
>
>
> 
>
>