Hello, пн, 2 мар. 2020 г. в 21:44, Niels Möller <[email protected]>: > > I've been offline, skiiing, for a week, and I haven't yet caught up we > email. http://www.lysator.liu.se/~nisse/misc/s%C3%A5nfj%C3%A4llet.jpg > > Michael Weiser <[email protected]> writes: > > > Hi Niels, > > > > On Sat, Feb 22, 2020 at 07:58:10AM +0100, Niels Möller wrote: > > > >> Lookingup NSLU2 on wikipedia, it seems it features a "Intel XScale cpu" > >> featuring an "ARMv5TE ISA without the floating point instructions." I > >> take it this can be run in BE mode? > > > > The Intel XScale and IXP4xx are BE by default, IIRC. For them it's even > > a bit of a hike to run them LE since all their companion controllers and > > firmware blobs are BE as well. > > Ok, so than ARM BE may be more relevant for these older chips than for > newer ones, which are almost always run in LE mode?
It has become mostly irrelevant after authors of SlugOS have invented a way to run LE binaries on NSLU2. Working in embedded hardware area I haven't seen an armeb project for ages. > > >> 2. Eliminate use of rev in the armbe code. > > > > ... I've been looking at the revs and they now strike me as taking the > > easy way out anyway. They work around the implicit LE order in which > > some remaining bytes from a buffer are saved byte-wise. This should be > > doable without the revs by making the store work in BE fashion in BE > > mode. I plan to look into this but would certainly appreciate any help > > Dmitry and Андрей might be able to give here since it's not as if I've > > been doing nothing but arm asm the last couple of years - rather the > > opposite. > > I've only had a quick look at the patch later in the thread, but I agree > that if we have a loop to store a byte at a time anyway, it should be > straight forward to "just" reverse the shifting direction depending on > byte order. > > >> 3. Somehow arrange in configure so that the memxor files in particular > >> aren't used when targetting armv5be. If you want to test the effects > >> before hacking configure.ac, I think it should be as easy as removing > >> the memxor*.asm symlinks after running configure. > > > > Nah, we can do better than that. :) > > But relatedly, it looks like arm/v6/sha1-compress.asm and > arm/v6/sha256-compress.asm need ARMv6 only on little-endian hosts. So it > might be worthwhile to try to use these files on armv5be? I don't see an > obvious great way to set it up though. > > One way might be to add a arm/be/sha1-compress.asm file which simply > includes the v6 file, and then add arm/be to the asm_path where > appropriate. I will take a look on fixing the code for armv5. Replacing rev with bit fiddling should be easy. -- With best wishes Dmitry _______________________________________________ nettle-bugs mailing list [email protected] http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
