New ldconfig flag values for ARM hard-float (and AArch64)

[Steve McIntyre <steve dot mcintyre at linaro dot org>]

Hi folks,

I started discussion back in July about adding support for new ELF
data to help in distinguishing between soft-float and hard-float ABI
binaries on ARM. We have code in
ports/sysdeps/unix/sysv/linux/arm/ldsodefs.h which will use new ELF
flag values, and recently matching changes have been accepted in
binutils to generate those flag values as appropriate when linking new
programs and shared libraries.

These two changes will work together fine, but for runtime
sanity/performance in ld.so I believe we should add tags in the
ldconfig cache to match. I'll send a patch for that shortly. As this
is going to touch both core code (elf/cache.c and
sysdeps/generic/ldconfig.h) and ports code, would people prefer
separate patches going to libc-alpha and then libc-ports? Or should I
provide the changes in one piece?

Also, while I'm in this area - clearly the new AArch64 port should
also get a tag value assigned for the ldconfig cache, in the same way
as other platforms. Maybe merge that in with the armhf changes as
they're in the same area, or are separate patches preferred?

Cheers,
-- 
Steve McIntyre                                steve.mcintyre@linaro.org
<http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs