Subject: Re: arm26 progress (lots)
To: None <firstname.lastname@example.org>
From: Jason R Thorpe <email@example.com>
Date: 04/24/2000 08:19:17
[ Let's please redirect the discussion to port-arm32/port-arm26; now we're
talking toolchain stuff... ]
On Mon, Apr 24, 2000 at 10:17:59AM +0100, Ben Harris wrote:
> Sort of. My binutils is just stock binutils-000413 (i.e. a recent Cygnus
> snapshot) configured with --target=arm-acorn-elf. GCC is gcc-2.95.2 using
> arm/netbsd.h with arm/elf.h instead of arm/aout.h (and a few other tweaks).
> I suspect in either case, backporting the changes into the standard NetBSD
> toolchain will be interesting, and a lot more work than I've done so far.
Okay, so a question... What did you do about the structure alignment
issue? As you probably know, the standard ARM ABI specifies that all
structures have a minimum alignment of 4 bytes, even if the members of
the structure have a less strict alignment. A perfect example of this
is struct ether_header.
When the port to the ARM was originally done, it looks like Mark and/or
Neil cheated (just a little! :-) and relaxed the alignment constraints in
the compiler (arm/netbsd.h I guess is where this was done).
Did you also relax this in the ELF toolchain?
It's pretty important because, if you didn't:
- We have to make absolutely sure that all protocol headers
use the __packed__ attribute.
- We have to allocate a new magic number, since binaries are
now using a different ABI.
-- Jason R. Thorpe <firstname.lastname@example.org>