Re: git: 74704a26bc2c - main - efi: Create a define for memory descriptor version

On Fri, Aug 26, 2022 at 11:45 AM Jessica Clarke <jrtc27@freebsd.org> wrote:

> On 26 Aug 2022, at 18:41, Warner Losh <imp@FreeBSD.org> wrote:
> >
> > The branch main has been updated by imp:
> >
> > URL:
> https://cgit.FreeBSD.org/src/commit/?id=74704a26bc2cfc72de6821d29a1f53b9d8c65f55
> >
> > commit 74704a26bc2cfc72de6821d29a1f53b9d8c65f55
> > Author:     Warner Losh <imp@FreeBSD.org>
> > AuthorDate: 2022-08-26 17:39:37 +0000
> > Commit:     Warner Losh <imp@FreeBSD.org>
> > CommitDate: 2022-08-26 17:40:42 +0000
> >
> >    efi: Create a define for memory descriptor version
> >
> >    For true EFI platforms, the EFI BIOS will return version 1 (since no
> >    other version is defined as of this commit). However, for environments
> >    that wish to create an EFI memory mapping table that aren't actually
> >    EFI, we need to know this. Add EFI_MEMORY_DESCRIPTOR_VERSION for this
> >    constant.
>
> Should such environments not be hard-coding version 1? Otherwise you
> risk starting to silently create version 2 structures in the future if
> this is bumped, but initialised as if they were version 1, which could
> mean leaving some new fields uninitialised.
>

Hmmm, currently we don't check the version.... But we likely should
add an assert to say that this version is 1, because who knows what version
2 will bring... But yes, it's a good idea to be explicit about that.

Warner