Re: [PATCH v3 11/11] x86: support i386 with Clang

From: Sedat Dilek
Date: Fri Jul 24 2020 - 09:22:18 EST

On Thu, Jul 23, 2020 at 3:56 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Thu, Jul 23, 2020 at 3:14 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> > What happens when there is no CONFIG_64BIT line?
> > There exist explicit checks for (and "inverse") of CONFIG_64BIT like
> > "ifdef" and "ifndef" or any "defined(...)" and its opposite?
> > I remember I have seen checks for it in x86 tree.
> As long as you consistently pass ARCH=i386 when running 'make',
> nothing bad happens, as ARCH=i386 just hides that option.
> If you run "make ARCH=i386 defconfig" followed by "make olddefconfig"
> (without ARCH=i386) on a non-i386 machine, the absence of that
> CONFIG_64BIT line will lead to the kernel going back to a 64-bit
> configuration.

Again thank you for your feedback.

Unsure if people are aware of the different behaviours and results.

That's why I keep the same make line with and without "defconfig".

Unfortunately, I had no opportunity to test the patchset :-(.

For testing I had done:
$ MAKE_OPTS="..."
$ ARCH=x86 make V=1 -j3 $MAKE_OPTS i386_defconfig (whereas V=1 and -j3
can be dropped of course)
$ ARCH=x86 make V=1 -j3 $MAKE_OPTS

How wonderful my patch "x86/defconfigs: Remove CONFIG_CRYPTO_AES_586
from i386_defconfig" landed in <tip.git#x86/build>.

- Sedat -