Re: [Gcl-devel] [PATCH 00/11] Add support for AArch64

[Camm Maguire]

Greetings!

Will Newton <address@hidden> writes:

>> More on your patches later, but dlopen is really a last resort.  The
>> limitation on open file descriptors alone makes it almost useless for
>> acl2.  We have many custreloc targets making use of some sort of
>> trampoline, and I'd be happy to implement the same here, if machine
>> access can be made available.  The quickest though non-optimal custreloc
>> port is usually via some -mlongcalls switch to gcc.  Is this available
>> here?
>
> gcc aarch64 does not have -mlong-calls, and the closest equivalent,
> -mcmodel=large is incompatible with PIC. Could you point me to the
> code where other architectures implement trampolines? I had expected
> to find something like that but it wasn't obvious to me where the work
> was done.
>

Look at the mips, ppc, alpha reloc headers under h/.  Mips is the most
complex, so I suggest starting with alpha.

Also, while I greatly appreciate your work on master, which will be
incorporated, this is the bleeding edge branch.  To get a quick
port into the soon to be released 2.6.11, please look at the cygwin
branch in git.  (So named, as cywgin, ppc64, and solaris will be newly
supported targets.)  The release cycle (thus far) has basically been --
bold ideas into master and branches thereof, then every year or so move
the best ideas into the stable series 2.6.x.  These are released as
Debian packages to test the supported apps on the autobuilders.  So
2.6.10-1 in Debian is the official 2.6.10 release, and 2.6.10-14 (now)
is the test of the forthcoming 2.6.11.

To get a trampoline working should not demand a lot of speed.  I've used
aranym to maintain m68k even :-).  But you might be in the best position
to suggest a patch here.  Even if gcc does not support longcalls, if you
know how to load a 64bit word into register and jump there, and how to
set the return, and have maybe an objdump snippet, we can work from that.

Take care,
-- 
Camm Maguire                                        address@hidden
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