[syslinux] Isohybrid wiki page and UEFI

[Ady]

> Hello,
> 
> Ady via Syslinux said on Sat, Oct 24, 2015 at 12:56:26AM +0300:
> >> EFI expects 0 "no emulation", although 4 "hard disk" would have
> >> been an obvious choice, too.
> >> But probably they wanted to avoid the need for partition table
> >> interpretation inside the EFI System Partition.
> >>
> >
> >And here is the issue :-O. Or I should say, the lack of simplicity and
> >clarity from 1600+ pages, containing even simple-to-spot typos -- which
> >are kept from one version to the next one anyway, showing the lack of
> >the most basic proof-reading -- thus generating confusion.
> 
> If you have any improvement for the Spec, please feel free to enumerate
> the problems you're encountering here, as I have a way to report that to
> the people in charge of making updates, and we could hopefully improve
> the status with the help of this community.
> 
> >So, someone could assert the
> >following reasoning steps:
> >
> >1_ We can workaround the Sector Count limitation of 32MiB for
> >no-emulation methods.
> >2_ The ESP is considered a no-emulation method.
> >3_ From the above assertions, we could conclude that the limitation of
> >32MiB is not really relevant for the ESP.
> 
> In order to remove that potential problem, I'm now generating 30 MB
> boot images. May not solve my final problem, but can help make
> progresses. Still the same issue. Even with 6.04 link given to me.
> 
> >This would mean that, in spite of the UEFI specs stating that the
> >Sector Count "field" determines the size of the ESP on optical media,
> >this initial limitation could be overrun by means of some workaround.
> >
> >To be clear, with "workaround" I don't mean the "size of 0 or 1"; I
> >mean similar workarounds as for no-emulation methods under BIOS.
> 
> Best regards,
> Bruno.
 
Other than potentially improving the UEFI Specs (which won't "solve" 
the 1600+ pages-long document, of course), do you have any reply to my 
other comments / suggestions? [1]

Please note that the size's change of the FAT image (to less than 
32MiB) is not the only "suggestion" -- or, are these "conditions", 
"shall", "must"? -- that the UEFI Specs mention about the FAT1x image 
for booting optical media booting in UEFI mode.

Whether (some) real-life firmware actually require only part of the 
UEFI Specs points regarding the FAT image on optical media, that's 
another matter (with pros and cons).

Regards,
Ady.

[1]:
 http://www.syslinux.org/archives/2015-October/024501.html