[Clfs-support] Fwd: [lfs-dev] lfs-multilib question

[Roger Koehler]

---------- Forwarded message ----------
From: Roger Koehler <roger.o.koehler at gmail.com>
Date: Fri, Sep 8, 2017 at 7:19 AM
Subject: Re: [lfs-dev] lfs-multilib question
To: LFS Developers Mailinglist <lfs-dev at lists.linuxfromscratch.org>


On Thu, Sep 7, 2017 at 9:52 PM, Ken Moffat <zarniwhoop at ntlworld.com> wrote:
> On Fri, Sep 08, 2017 at 02:12:05PM +1100, evanation wrote:
>> Can I recompile other libraries as needed, but not in the installation process?
>>
>> 2017-09-08 13:10 GMT+11:00 James B <jamesbond3142 at gmail.com>:
>> > On Fri, 8 Sep 2017 11:50:00 +1100
>> > evanation <evanation.ru at gmail.com> wrote:
>> >
>> >> to get a multilib, is it enough in chapter 5 and in chapter 6 to
>> >> compile glibc-32bit and glibc-64bit?
>> >
>> > No.
>> >
>> > In addition to glibc, almost all other libraries in both chapters needs to be build in 32/64 version.
>> > You may instead check CLFS: http://clfs.org/view/sysvinit/x86_64/ (this is for x86-64 platform, there are similar guides for other platform too).
>> >
>
> It's a long time since I built multilib - I compile everything from
> source, I have no need for 32-bit x86.  But my memory says "Maybe
> you can build other libaries 32-bit - as needed - after booting."
>
> It all depends on what you want to do with the system - CLFS will
> give you a system where you can compile 32-bit as well as 64-bit.
> If all you want to do is run some 32-bit binary (statically linked
> so that it doesn't need more than libc) then just building glibc as
> 32-bit might work.
>
> OTOH, it might not - if you want to do it, you can test it and find
> out.  A quick test (trying to compile a mickey-mouse program with
> gcc -m32) on x86_64 failed because I lack the 32-bit stubs which I
> think come from glibc.  But for at least a couple of years we (LFS)
> have had to build libstdc++ to get everything working, so I suspect
> that all the toolchain (binutils, gcc, glibc, and the extra libs
> added into the pass1 gcc build) will need to be built as both 32-bit
> and 64-bit.  I'm assuming sysvinit - for systemd you probably also
> need 32-bit versions of whatever libraries that requires, and their
> dependencies.
>
> Summary: I can't personally see the point of multilib (so much extra
> to build, then for everything in BLFS you need to specify -m32 or
> -m64, and --libdir when it is not lib), but you will get more
> reliable results from following the CLFS build - or more learning
> experiences by trying to simplify it :)

The compelling reason for me is so that I can run applications that
depend on 32-bit Microsoft libraries that can be emulated by wine when
properly (with the 32-bit libraries) installed.

I don't have a lot of extra time, so I've been hoping that someone on
one of these lists will publish an easy, step by step (in the LFS
tradition) guide on how to do it.

I like LFS/BLFS because of how up-to-date (thanks Bruce, et al) and
especially how easy jhalfs (thanks Pierre, et al) makes it to build a
complete, working, system (as long as you don't mind quickly
inspecting and editing some of the scripts that are generated, the
majority of which just work as is).

I like how the jhalfs tools include a simple way to keep the system up
to date by simply running "make update" in blfs_root and now includes
the LFS book.

It would be really great if there were a simple add on to LFS/BLFS
that you could select in jhalfs to add the necessary 32-bit libraries
to build wine. (I have been frustrated trying to follow CLFS, and
would like to just add to an existing 64-bit LFS/BLFS system.)

Great works guys.

Roger