Bug 44931
| Summary: | Kernel fails to build on Processor family=386 | ||
|---|---|---|---|
| Product: | Platform Specific/Hardware | Reporter: | Mario Gzuk (mariogzuk) |
| Component: | i386 | Assignee: | platform_i386 |
| Status: | RESOLVED OBSOLETE | ||
| Severity: | normal | CC: | alan, hpa, ysangkok |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 3.4.x | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
Kernel Konfig for 3.4.5
CMPXCHG8B software emulation patch |
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Hi, same issue with 3.5.x and 3.6.x. What am I doing wrong? Do you actually care about 386? If so, why? The reason I'm asking is that we are seriously considering ripping out the remains of 386 (as opposed to 486) support... The problem is that the llist code uses cmpxchg() unconditionally, and the 386-specific fallback code doesn't seem to actually get picked up properly. Hi Peter Anvin, this config is used in the project uranos.sf.net. The kernel is used in a boot environment which has to be the possibilities to deploy windows (and do also other stuff e.g. like offline virus scanning) on a wide range of machine types which should be also compatible with i486, i586 or i686 too. The main problem we have is that if we changed the machine type to i486 (or i586/i686) the kernel build runs fine, but if we try to boot that kernel via PXE (or CD via syslinux) the last message I see is: "booting the kernel" and the system stays @ 100% CPU load and do nothing (VBOX). So I actually dont know if this is related to the 386. But I think if there is a possibility to use i386, it should also compile with this option?! All versions in the 3.2.x are working fine and also boot via syslinux. Thank you for your time! An issue with 486+ would be totally unrelated and needs to be discovered separately. I would recommend doing a "git bisect" from the last known working version. So I should do that like decribed here: http://www.kernel.org/pub/software/scm/git/docs/git-bisect.html ? From the 3.2.34 to the next version which is not working? Or the latest version not working? From 3.2 assuming it is working to the first mainline (two-digit) version which is not working. Sorry for asking again. I never checked out any thing with git. Finding the right place from http://git.kernel.org/ seems to be very hard. Can you write me s short (as possible) howto do that? Thank you! git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git So as you removed the code from the kernel, I think you dont need the bisect things... So you may want to close this report... Thanks for your time. Cheers Mario I still care about the OTHER bug you reported: "The main problem we have is that if we changed the machine type to i486 (or i586/i686) the kernel build runs fine, but if we try to boot that kernel via PXE (or CD via syslinux) the last message I see is: "booting the kernel" and the system stays @ 100% CPU load and do nothing (VBOX). " That is the one I would really like to find the answer to. Oh. Thank you. I have tested now the 3.2.34 with i386 switch to i686 and all works fine. I never got a kernel from 3.[456] booting via syslinux/pxelinux. Maybe I have to check the .config again, but as far as I can see all the settings which affects this are correct. I will give it a try again with 3.6.8 and the config from the working 3.2.34 (i686). If there are some news I will let you know. Cheers Hi, the last test runs fine with 3.6.8 (i686) - I am now able to boot via PXE (also syslinux from iso). Maybe I had a wrong config which was not working. Thank you for your time! Cheers Created attachment 89271 [details] CMPXCHG8B software emulation patch (In reply to comment #3) > The problem is that the llist code uses cmpxchg() unconditionally, and the > 386-specific fallback code doesn't seem to actually get picked up properly. BTW there's a pentium_emu patch by Alexander Chumachenko that provides i586 instructions emulation for i486 (e.g. eBox 2300SX, we hit those with ALT Linux Terminal distro) -- attaching just in case, sorry if that's spam here, willing to post separately if found somewhat useful. This bug relates to a very old kernel. Closing as obsolete. Isn't 3.4 still maintained? I have this problem with 3.4.106. AFAIK, this is the most recent kernel with support for the i386. It's sad that it doesn't work; it makes it hard for people with legacy emulators or legacy hardware to find the latest kernel that will work for them. If you want 386 support then the only way it will happen is if someone (ie you) wants to do the *huge* amount of work required to update 386 support and keep it working. The 386 requires a huge amount of additional nasty and complex code that is not needed from 486 onwards. |
Created attachment 75771 [details] Kernel Konfig for 3.4.5 Hi, if I change the Processor family to 386 the following errors start with building the kernel: make CC=gcc HOSTCC=gcc ARCH=i386 SEVERAL: include/linux/llist.h: In function 'llist_add': include/linux/llist.h:160:11: warning: initialization makes pointer from integer without a cast [enabled by default] include/linux/llist.h:160:11: warning: initialization makes pointer from integer without a cast [enabled by default] The buld dies @: CC arch/x86/kernel/irq_work.o In file included from include/linux/irq_work.h:4:0, from arch/x86/kernel/irq_work.c:8: include/linux/llist.h: In function 'llist_add': include/linux/llist.h:160:11: error: 'boot_cpu_data' undeclared (first use in this function) include/linux/llist.h:160:11: note: each undeclared identifier is reported only once for each function it appears in include/linux/llist.h:160:11: warning: initialization makes pointer from integer without a cast [enabled by default] include/linux/llist.h:160:11: warning: initialization makes pointer from integer without a cast [enabled by default] make[2]: *** [arch/x86/kernel/irq_work.o] Error 1 make[1]: *** [arch/x86/kernel] Error 2 make: *** [arch/x86] Error 2 If I changed the processor type to something other (e.g. 486 or any other) the build runs fine. This happens to all kernel versions 3.4.x The gcc used (ubuntu 12.04 i386) gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.6/lto-wrapper Target: i686-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu Thread model: posix gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) Attached is the kernel config for family 486 -> if you change this to i386 the build fails with the above error. Thank you