Bug 1034897

Summary: RFE support building 64 bit kernel on 32 bit OS
Product: [Fedora] Fedora Reporter: Michael S. Tsirkin <mst>
Component: gccAssignee: Jakub Jelinek <jakub>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
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Version: rawhideCC: jakub, law
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Last Closed: 2013-12-07 08:42:45 UTC Type: Bug
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Description Michael S. Tsirkin 2013-11-26 16:45:39 UTC
Description of problem:
on debian/ubuntu, gcc supports -m 64 flag well enough to
cross-build a 64 bit kernel on a 32 bit OS by using 

Version-Release number of selected component (if applicable):
gcc (GCC) 4.8.2 20131017 (Red Hat 4.8.2-1)


How reproducible:
always

Steps to Reproduce:
1. create a small c file e.g. echo 'void foo(void) {}' > x.c
2. compile with -m 64: gcc -c -m64 -o x.o x.c
3
Actual results:
$ gcc -c -m64 x.c
x.c:1:0: sorry, unimplemented: 64-bit mode not compiled in


Expected results:
create 64 bit object file

Additional info:
this is a requirement for using 64 bit kernels in 32 bit
fedora which I'd like to make work again:
you must be able to build the kernel you are using.

Comment 1 Michael S. Tsirkin 2013-11-26 16:46:11 UTC
note: works on debian and ubuntu

Comment 2 Jakub Jelinek 2013-12-07 08:42:45 UTC
Just install cross-gcc then.