Hi! Neither do I really know anything about Xtensa, nor do I have a lot of experience in these parts of GCC back ends, but:
On Tue, 6 Sep 2016 20:42:53 +0200, Oleksij Rempel <li...@rempel-privat.de> wrote: > i'm one of ath9k-htc-firmware developers. Currently i'm looking for the > way to provide this firmware as opensource/free package for debian. Main > problem seems to be the need to patch gcc xtensa-config.h to make it > suitable for our CPU. > > I have fallowing questions: > > do we really need this patch? > https://github.com/qca/open-ath9k-htc-firmware/blob/master/local/patches/gcc.patch That I can't tell. ;-) > Is it possible or welcome to extend gcc to be configurable without > patching it all the time? Yes, I would think. The macros modified in the above patch to GCC's include/xtensa-config.h file look like these ought to be modifiable with -m* options defined by the Xtensa back end, and you'd then assign specific defaults to a specific CPU variant, and build GCC (or build a multilib) for that configuration. This file include/xtensa-config.h is #included in gcc/config/xtensa/xtensa.h and libgcc/config/xtensa/crti.S, libgcc/config/xtensa/crtn.S, libgcc/config/xtensa/lib1funcs.S, libgcc/config/xtensa/lib2funcs.S, but I have not checked how the macro definitions are actually used. In gcc/doc/install.texi I read: @anchor{xtensa-x-elf} @heading xtensa*-*-elf This target is intended for embedded Xtensa systems using the @samp{newlib} C library. It uses ELF but does not support shared objects. Designed-defined instructions specified via the Tensilica Instruction Extension (TIE) language are only supported through inline assembly. The Xtensa configuration information must be specified prior to building GCC@. The @file{include/xtensa-config.h} header file contains the configuration information. If you created your own Xtensa configuration with the Xtensa Processor Generator, the downloaded files include a customized copy of this header file, which you can use to replace the default header file. @html <hr /> @end html @anchor{xtensa-x-linux} @heading xtensa*-*-linux* [...] Hmm. CCing Sterling Augustine who is listed as the Xtensa CPU Port Maintainer. Grüße Thomas
signature.asc
Description: PGP signature
