Re: Kconfig: ARCH=x86

Andreas Herrmann
2007-11-16T11:41:57Z

On Fri, Nov 16, 2007 at 12:14:46PM +0100, Andreas Herrmann wrote:
> BTW, is the x86 kernel build documented somewhere?
> At a first glance I didn't find anything suitable under Documentation/.
> Maybe some explanation (like the above) should be added there.

When the ARCH=x86 build is documented, some words about
cross-compilation should be added:

(1) To compile a 32-bit kernel on a 64-bit system you have to
Disable 64bit support in menuconfig (config, oldconfig etc.). A
subsequent kernel compile will build a 32-bit kernel. No cross
compiler is needed.

(2) To compile a 64-bit kernel on a 32-bit system you have to switch
on 64-bit support in menuconfig (or config, oldconfig, etc.). For
the subsequent kernel compile a cross compiler (supporting 64-bit)
is needed. You have to use a command line like

# make CROSS_COMPILE=x86_64-pc-linux-gnu-

to cross compile your kernel.

Regards,

Andreas