> From: Andre McCurdy [mailto:armccu...@gmail.com] > > Isn't the point of x32 that the kernel should be full 64bit (and so > able to directly address all memory) and only user space should be > restricted to 32bit pointers? > > If so, then the kernel ELF architecture x86-64 seems correct. If that > kernel can't run x32 user space binaries then maybe the kernel config > option to enable support for x32 user space is somehow missing?
You're probably right, although I never saw any docs that spelled that out. That would explain why there are libx32 directories. I was hoping that x32 just meant that everything was compiled with a single architecture, just like a 32-bit processor, just using 64-bit mode for the larger register set, and 32-bit pointers everywhere. No need for any multi-arch logic. That would seem to be desirable for a modest sized embedded system. But if it still produces a 64-bit kernel, I can live with that, as long as I can get it to work. > From: Bruce Ashfield [mailto:bruce.ashfi...@gmail.com] > > I can't think of a reason off the top of my head that would > prevent this from working at the kernel level. > > But can you confirm that a non-rt build for the same board works with > x32 ? It could just be a kernel configuration issue if it > does work with > non-rt, since the -rt variant may not have a BSP entry point defined. I did more thorough testing, doing six core-image-minimal builds: 32, 32rt, 64, 64rt, 64x32, and 64x32rt. All the non-rt ones and the 64rt one work. The 32rt and 64x32rt both panic loading init. I'm not sure if I'm specifying the rt kernel properly. My 32-bit local.conf includes MACHINE = "genericx86" PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto-rt" PREFERRED_VERSION_linux-yocto-rt ?= "4.8%" and my 64-bit x32 local.conf includes MACHINE = "genericx86-64" DEFAULTTUNE = "core2-64-x32" baselib = "${@d.getVar('BASE_LIB_tune-' + (d.getVar('DEFAULTTUNE', True) \ or 'INVALID'), True) or 'lib'}" PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto-rt" PREFERRED_VERSION_linux-yocto-rt ?= "4.8%" I have a tiny layer that just includes a linux-yocto-rt_4.8.bbappend: COMPATIBLE_MACHINE = "genericx86|genericx86-64" KERNEL_FEATURES_append = " ${@bb.utils.contains("TUNE_FEATURES", \ "mx32", " cfg/x32.scc", "" ,d)}" and a non-rt one just specifying COMPATIBLE_MACHINE. I copied that last line from the linux-yocto_4.8.bb file, because it's not in the rt recipe. The .scc file pulls in a .cfg file which turns on CONFIG_X86_X32 and CONFIG_COMPAT. Yet the problem isn't with x32, it's that it can't run 32-bit binaries, even in a plain 32-bit kernel. So what am I leaving out, in my effort to specify the rt kernel? -- Ciao, Paul D. DeRocco Paul mailto:pdero...@ix.netcom.com -- _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
