[Clfs-support] i586 target with cmov

[Chris Fowler]

This is where I'm confused.  I guess I was expecting was that all packages
created in chapter 5 to be truly targeted to i586.  Of course I'm still
compiling in 6.  Add in that I'm doing this on x86_64 and targeting i586
the host and target are too similar to get a good lesson in cross-compiling
a system.  It may be helpful if I was to use a host
of arm-cross-linux-gnueabihf to target i586.  Probably be a two day
compile. :)

Currently I'm at 10.11 and have chroot'ed into CLFS via the i586 machine by
mounting it NFS, setting virtuals, and doing the chroot.  I'm going to
finish up the chapter there.

If your curious this is the target:

root:~/ch10# cat /proc/cpuinfo
processor : 0
vendor_id : Genuine  RDC
cpu family : 5
model : 8
model name : 05/08
stepping : 6
cpu MHz : 999.991
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu tsc cx8 mmx up
bogomips : 1999.98
clflush size : 32
cache_alignment : 32
address sizes : 32 bits physical, 32 bits virtual
power management:


Linux cs-buford.k4fh.com  2.6.38 #135 SMP Fri May 13 19:16:23 UTC 2016 i586
GNU/Linux

Eventually I'd like to do the multi, but for all packages.  The same root
would target the RDC (i586) and a J1900 BayTrail (i686 32).  My kernels
will be same version, but different processor config.  I could use initrd
to then create all proper symlinks in root before executing pivot_root.
These systems are small and the root it actually loaded off flash into a
ramdisk.  The RDC sis discontinued, but I still need to support it.

Chris

On Tue, May 17, 2016 at 4:35 PM, William Harrington <kb0iic at berzerkula.org>
wrote:

> On Tue, May 17, 2016 19:06, Chris Fowler wrote:
> > Yea, I've compiled Linus' code and ran on the RDC3308 itself.  I've not
> > compiled the code in this environment.  I'm not sure if I should see cmov
> > instructions in the binary or not.  I am using uname hack.  If I rebuilt
> > gmp and coreutils would cmov be included?
> >
> Hello Chris,
>
> In gmp configure git master:
>
> i586 | pentium)
>         gcc_cflags_cpu="-mtune=pentium -mcpu=pentium -m486"
>         gcc_cflags_arch="-march=pentium"
>         path="x86/pentium x86"
>
> You can do what is done in ch10 during ch6 GMP build:
>
> mv -v config{fsf,}.guess
> mv -v config{fsf,}.sub
>
> Then it'll use generic targets not optimized with the host CPU.
>
> I don't know if cmov will be removed. GMP checks the assembler to see if
> supports cmov, and is supposed to be enabled in gmp when i686/pentium pro
> or newer is in the target triplet. It isn't supposed to be included with
> i586/pentium or older.
>
> Sincerely,
>
> William Harrington
> _______________________________________________
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> Clfs-support at lists.clfs.org
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>
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