Re: FreeBSD EFI projects

> On Wed, Sep 19, 2018 at 6:06 PM, Rodney W. Grimes 
> <freebsd-rwg_at_pdx.rh.CN85.dnsmgr.net> wrote:
> >>  On Wed, Sep 19, 2018 at 5:34 PM, Rodney W. Grimes
> >>  <freebsd-rwg_at_pdx.rh.CN85.dnsmgr.net> wrote:
> >>  >>  On 9/18/18 4:11 AM, Greg V wrote:
> >>  >>
> >>  >>  >
> >>  >>  > I can confirm that the kernel already worked fine when booted 
> >> from
> >>  >>  > 32-bit EFI.
> >>  >>  >
> >>  >>  > I booted an old Mac into HardenedBSD using a 32-bit-EFI build 
> >> of
> >>  >> GRUB2 :)
> >>  >>
> >>  >>
> >>  >>  Was that a 64-bit version of FreeBSD? My understanding is the 
> >> 32-bit
> >>  >>  FreeBSD boots fine, but 64-bit needs work.
> >>  >
> >>  > You would be hard pressed to find a system with a 64 bit CPU that
> >>  > could run 64 bit FreeBSD that had a 32 bit EFI implementation.
> >> 
> >>  Mac mini 2006 with a Core2Duo instead of the stock CoreDuo (and the
> >>  2007 model's firmware flashed, but I don't think that impacts 
> >> FreeBSD).
> > 
> > Yes, that is one of the catagories of rare, a EFI-32 bit system that
> > was originally shipped with a 32 bit only CPU, that later got upgraded
> > in the field with a 64 bit CPU, that still runs a EFI-32 bios.
> > Are you sure the 2007 firmware is EFI32?  I would of thought
> > since they upgraded the base system to a 64 bit CPU they would
> > of shipped it with a EFI-64 bios.
> 
> The EFI firmware is technically 64 bit? but it only boots 32-bit 
> binaries.
> 
> https://everymac.com/mac-answers/snow-leopard-mac-os-x-faq/mac-os-x-snow-leopard-64-bit-macs-64-bit-efi-boot-in-64-bit-mode.html
> 'Furthermore, it appears that although subsequently released MacBook, 
> MacBook Air, and pre-"Mid-2010" Mac mini models all are equipped with 
> "Core 2 Duo" 64-bit processors and 64-bit EFIs, Apple has blocked these 
> "consumer-targeted" Macs from booting in 64-bit mode. iMac and MacBook 
> Pro models released in 2007 with 64-bit EFIs seem to have been blocked 
> as well.'

That is not EFI32, so that is not a test case for how FreeBSD boots                                                                                                    
on EFI32 systems.  That is a restriction apple artificially placed
in the implementation.

> >>  And probably just the 2007 model as well :)
> >> 
> >>  Also, IIRC there were some Intel Atom tablets with 32-bit EFI.
> > 
> > Atom N2xx and Z5xx series Atom models cannot run x86-64
> 
> Atom Z3740 ? "Instruction Set: 64-bit"
> https://ark.intel.com/products/76759/Intel-Atom-Processor-Z3740-2M-Cache-up-to-1_86-GHz

The above does not say Atom Z3xxx.  If you find a Atom
N2xx or Z5xx based system it most certainly has a EFI32.

> 
> The tablet in question: ASUS VivoTab Note 8 (M80TA)
> https://www.asus.com/us/Tablets/ASUS_VivoTab_Note_8_M80TA/

I can not find enough detail to know for certain that tablet
actually has which version of EFI.
You are saying it has EFI32?  And if so based on what information?

-- 
Rod Grimes                                                 rgrimes_at_freebsd.org