arm questions

[Ian Lance Taylor]

   Date: Thu, 15 Apr 1999 10:38:25 -0700
   From: Doug Evans <devans@cygnus.com>

   Two random questions.

   1)
   elfarm-oabi.c uses USE_RELA
   elfarm-nabi.c uses USE_REL
   That seems rather backwards, doesn't it?
   I'd expect a new version of an abi to switch from USE_REL to USE_RELA,
   but not the other way around.
   [not that it can be changed, but rather ... why the switch?]

This is my understanding of the situation.  If anybody knows that I am
wrong, please correct me.

The ARM ELF situation is a mess because there were two separate
implementations.

Some folks in England put together ARM GNU/Linux, but they took a very
long time to get the copyright stuff done.  For some reason that I do
not know, that implementation used REL rather than RELA relocs.

In the meantime, Cygnus implemented ARM ELF, using RELA relocs.

It's obviously desirable to have a single ARM ELF ABI, and the best
choice is probably the one currently being used for GNU/Linux.
Therefore, when we straightened out the copyright situation, we dumped
the Cygnus RELA implementation in favour of the GNU/Linux REL
implementation.

   2)
   Whats the R_ARM_THM_XPC22 reloc for?

I dunno.  Philip Blundell is on the list.  Phil, do you know?

Ian