ABI/architecture identification for packages

Hi all,

In order to identify architectures I need to find a uniq id for every
possibilities (for pkgng)

here is the identification I propose:

arch-class-os-majorversion(-archi_specific_extension)

arch can be one of the following:

- x86 for i386 and amd64 (discussed with kib)
- powerpc for powerpc and powerpc64
- arm
- mips
- sparc

class may be:
- 32 bits
- 64 bits

os will always be freebsd :) (lower case)

majorversion the freebsd major version (10 9 8)

achi_specific_extension currently only mips and arm are concerned,
for arm could be:
el_oabi
eb_oabi
el_eabi
eb_eabi

(I don't know how to get arm version or hardfp/softfp from the elf)

for mips I don't know much.

for ia64, I have strictly no idea what I should set.

Everything is read from the elf file

for example:
x86-64-freebsd-10
x86-32-freebsd-8
arm-32-freebsd-10-el_oabi

Please help me to improve this to get the better identification to have the best
possible to determine which package can be installed where.

while proposing information please tell me how to get the information
(dynamically)

regards,
Bapt