On Mon, 2011-11-07 at 23:14 +0000, Julian Pidancet wrote: > On Wed, Oct 26, 2011 at 3:09 AM, McClintock Matthew-B29882 > <[email protected]> wrote: > > On Mon, Oct 24, 2011 at 8:18 PM, Julian Pidancet > > <[email protected]> wrote: > >> This patch introduces a distro feature which enables gcc to produce > >> both 32bit and 64bit code, and enables binutils to operate on both > >> 32bit and 64bit binaries. It differs from multilib toolchains in > >> that it does not require to compile a version of the libc for each > >> architecture variant. However, the code produced for the secondary > >> architecture will not be linkable against the libc. > >> > >> This patch only works with x86 and x86_64 architectures, but can > >> probably be extended to support other architectures as well. > >> > >> One use-case would be when one wants to compile a system which runs > >> 32bit userspace applications with a 64bit kernel without having to > >> deal with two separate libc. > > > > What happens with the native gcc on the root file system. And what > > about meta-toolchain? Any effect? > > > > Hi Matthew, sorry for the late answer. > > I'm affraid I don't quite see what you mean by "the native gcc on the > root file system". Are you refering to the version of GCC present on > the build machine and built by OE ? Or are you refering instead about > a potential version of GCC running on the target ? > > This patch should only make gcc-cross, and gcc running on the target > "biarch". It would also probably make sense to build a biarch GCC in > the meta-toolchain case. > > To be honest, I have not really considered the meta-toolchain case as > I've never used it before and not quite sure how it works. > > I can respin a patch to handle the meta-toolchain case. But in the > mean-time, it would be nice if I could get an opinion on wether this > "biarch" feature is a good idea or not, or, if not, maybe some > suggestions about how to address this specific 32bit/64bit use-case > differently.
I'm left wondering how useful the resulting compiler is to most users. In most cases a user would expect full libc support and hence this is likely to confuse them. I do appreciate people do have usecases for a compiler that can handle the other bit format though. I think my biggest worry is the "--enable-targets=all" option which may or may not enable things we might not want enabled. I've not had a chance to go and look at gcc and convince myself that piece is safe. The other pieces looked less worrying. Cheers, Richard _______________________________________________ Openembedded-core mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
