Nuno Teixeira wrote:
> Hello to all,
> 
> I came to this question when I use my i386 Athlon XP PC to create
> packages to old PCs based on I486 and I586 cpus.
> 
> Generally I don't use any -march or -mcpu gcc options to avoid problems.
> 
> I'm working and upgrading a Pentium 200 MMX and I like to optimize the
> packages with -march=pentium-mmx using my Athlon build system.
> 
> Is there any way to create packages with several optimizations like:
> 
> 	/usr/packages/2.0/i386_pentium-mmx/
> 	/usr/packages/2.0/i386_athlon-xp/
> 	/usr/packages/2.0/i386_pentiumpro
> 	etc...
> 
> Using only one build PC?
> 
> Thanks,
> 
> 	Nuno Teixeira

I think you can, say you're using Pentium 4 and want to build optimized 
packages for AMD Athlon, save the following file as 
'/etc/mk.athlon-tbird.conf' and before you build packages run:

MAKECONF=/etc/mk.athlon-tbird.conf
export MAKECONF

Here is mk.athlon-tbird.conf:

MACH_ARCH=athlon-tbird

LOCALBASE=/usr/pkg.${MACH_ARCH}
PKG_DBDIR=/usr/pkg.${MACH_ARCH}/db/pkg
WRKOBJDIR=/usr/obj.${MACH_ARCH}/pkg
PACKAGES=/usr/packages.${MACH_ARCH}
DEPENDS_TARGET=package

OPTIM_CPUFLAGS=-march=i486 -mcpu=athlon-tbird
OPTIM_CPUFLAGS2=-march=athlon-tbird -mmmx -m3dnow
OPTIM_CFLAGS=-O2 -pipe

.ifdef BSD_PKG_MK
COPTS+=${OPTIM_CFLAGS} ${OPTIM_CPUFLAGS2}
CFLAGS+=${OPTIM_CFLAGS} ${OPTIM_CPUFLAGS2}
CXXFLAGS+=${OPTIM_CFLAGS} ${OPTIM_CPUFLAGS2}
.else
COPTS?=${OPTIM_CFLAGS}
CPUFLAGS+=${OPTIM_CPUFLAGS}
.endif

- packages will be installed into /usr/pkg.athlon-tbird
- packages database will be in /usr/pkg.athlon-tbird/db/pkg
- gzipped packages will be saved into /usr/packages.athlon-tbird
- object files during build will be kept in /usr/obj.athlon-tbird/pkg

See 'man packages' for options to go into your mk.conf file
Before you install packages on the target machine you would need to 
setup symbolic link:

mkdir /usr/pkg.athlon-tbird
ln -s /usr/pkg.athlon-tbird /usr/pkg

The packages you built have hardcoded library paths to 
/usr/pkg.athlon-tbird package directory, but you can still reference all 
the executbles via /usr/pkg/bin/* as long as there is a symbolic link.

Other option is to build everything inside a chroot jail.