On Thu, 2015-05-07 at 12:01 +0200, Mathieu Malaterre wrote: > On Thu, May 7, 2015 at 11:41 AM, James Cowgill <james410@cowgill.org.uk> wrote: > > On Thu, 2015-05-07 at 11:25 +0200, Mathieu Malaterre wrote: > >> On Thu, May 7, 2015 at 10:57 AM, James Cowgill <james410@cowgill.org.uk> wrote: > >> > On Thu, 2015-05-07 at 09:27 +0200, Mathieu Malaterre wrote: > >> >> Hello MIPS gurus, > >> >> > >> >> Could someone please let me know if this is possible to have a > >> >> dual-ABI system (eg: n32 & o32) on MIPS. On my x86-64 system I can run > >> >> a multi-arch system (x86 & x86-64), thanks to the recent multi-arch > >> >> effort. > >> >> > >> >> Is it possible on MIPS ? Does it make sense ? > >> > > >> > If you have a 64-bit kernel then that should completely work (all Debian > >> > kernels except for 4kc are 64-bit). > >> > > >> > If you then install gcc-multilib you should be able to pass -mabi=n32 to > >> > gcc to get n32 binaries (or -mabi=64 for n64 binaries). I haven't done a > >> > huge amount of testing with it, but you should also be able to add the > >> > mips64el debian repo which contains everything recompiled with n64. Then > >> > you should be able to do proper multiarch. > >> > > >> > See: http://mipsdebian.imgtec.com/ > >> > >> I haven't received my Creator CI20 board yet, but I still fail to > >> understand how that's possible. On my x86-64 there is a *single* ABI, > >> and thus I can have a single `/usr/lib/x86_64-linux-gnu/libpthread.so` > >> installed from libc6-dev:amd64 which wont conflict with > >> `/usr/lib/i386-linux-gnu/libpthread.so` installed from libc6-dev:i386. > > > > The processor in the CI20 is 32-bit only so you won't be able to do any > > of this on that unfortunately. > > > > If you use mipsel / mips64el multiarch, the setup use on amd64 is > > identical on mips. Multilib places libraries in /lib32 or /lib64 just > > link it does on x86. > > > >> I may sound dumb, but I fail to understand how multi-abi can be > >> handled when directories are setup to handle (single) per-arch object > >> files. > > > > The directories *are* setup to handle multiple ABIs. 'i386-linux-gnu' is > > the ABI used on i386 and it is completely different to the > > 'x86_64-linux-gnu' ABI (you can't link amd64 and i386 objects together). > > My original post was about mixing n32 and o32. So if I try to > summarize your post (little endian ABI only): > > - debian `mipsel` refers to ABI `o32` > - debian `mips64el` refers to ABI `o64` > (https://gcc.gnu.org/projects/mipso64-abi.html) mips64el uses n64, not o64. > Debian has not been working officially on any of the n32 or n64 ABIs. Well it's not in the main archive yet, but there are a number of people working on it. > Now let me rephrase my original question into: > > Since Debian `mipsel` is using the old o32 ABI, would it make sense to > use n32 ABI on Creator CI20 ? n32 will not work on the CI20 because it only has a 32-bit processor. n32 is a 64-bit ABI with 32-bit pointers (very similar to x32). > As per your comment, I will not be able to use (=link to) the o32 > `libc` provided by the default debian `mipsel` package when building > an n32 application (gcc -mabi=n32). In which case the location > `/usr/lib/mipsel-linux-gnu/` will be reserved for object files with > o32 ABI, while something like `/usr/lib/mipsel-n32-linux-gnu/` may be > used for n32 ABI. Yes that's correct. Bear in mind that there isn't a n32 debian port so you'll have to compile any libraries you use (except glibc) yourself. James
Attachment:
signature.asc
Description: This is a digitally signed message part