Re: Deprecation of i386 and 32-bit powerpc for 15.0

Am Sat, Jun 21, 2025 at 06:39:03PM -0700 schrieb Rodney W. Grimes:
> > > > > What is going to be deprecated is 32bit bare-metal hardwares supports
> > > > > for i386 and 32bit PowerPC, which never runs on 64bit modes.  
> > > > 
> > > > Does that mean that support for 32-bit builds for virtual machines (that's
> > > > important because they use less memory -> buy cheaper, especially when
> > > > lots of them) will be continued after 2030 ?  
> > > 
> > > My understanding is, unfortunately, yes.
> > > IIUC, VM images are "pre-installed" environment with virtual disk
> > > format that the VM recognizes and pre-installed, if any, drivers to
> > > support emulated virtual hardwares.
> > > 
> > > You can still use 32bit binaries on 64bit builds of VMs, but
> > > it would require lib32 to be installed.
> > > 
> > > Correct me if I'm misunderstanding.
> >  
> > If "yes" then why "unfortunately" ? Continuing to support 32 bits where it
> > makes sense is very fortunate thing, both for cheaper prices and energy saving
> > thus our planet!
> 
> IMHO, it is a mistake for FreeBSD to remove the 32 bit bare metal build
> before Intel/AMD removes this support from the bare metal.  As long as
> shipping CPU chips from both AMD and Intel support 32 bit bare metal
> boots, and VM's it makes since for this feature to be availiable.

Instead of clinging to i386, it might be more interesting to get an ILP32 ABI
for amd64 implemented.  This gives various performance advantages over using
i386, the size savings of 32 bit pointers, and should not require complex kernel
changes.

> As one person here has pointed out the savings in VM sizes alone
> is valuable.
> 
> Also some one explain where the build of 32bit binaries would come from
> if the 32bit build of FreeBSD goes away?  That has me rather confused,
> other than possibly to run legacy things, but that interface is likely
> to get broken quickly once the 32 bit builds are gone.

You will still be able to run "make buildworld TARGET=i386", just not
"make buildkernel TARGET=i386".

> Or is it expected that we can continue to build a 32 bit user land
> from /usr/src and run that on the 64 bit kernel and that this shall
> be a fully supported configuration?

Correct, just as cross-compiling any other architecture from any
architecture is a supported configuration.

Yours,
Robert Clausecker

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