Re: [PATCH v2] powerpc: Support CMDLINE_EXTEND

[Christophe Leroy]

Le 02/08/2019 Ã 00:32, Chris Packham a ÃcritÂ:
> On Thu, 2019-08-01 at 08:14 +0200, Christophe Leroy wrote:
> > Le 01/08/2019 Ã 04:12, Chris Packham a ÃcritÂ:
> > > Bring powerpc in line with other architectures that support
> > > extending or
> > > overriding the bootloader provided command line.
> > >
> > > The current behaviour is most like CMDLINE_FROM_BOOTLOADER where
> > > the
> > > bootloader command line is preferred but the kernel config can
> > > provide a
> > > fallback so CMDLINE_FROM_BOOTLOADER is the default. CMDLINE_EXTEND
> > > can
> > > be used to append the CMDLINE from the kernel config to the one
> > > provided
> > > by the bootloader.
> > >
> > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > > ---
> > > While I'm at it does anyone think it's worth getting rid of the
> > > default CMDLINE
> > > value if CMDLINE_BOOL and maybe CMDLINE_BOOL? Every defconfig in
> > > the kernel
> > > that sets CMDLINE_BOOL=y also sets CMDLINE to something other than
> > > "console=ttyS0,9600 console=tty0 root=/dev/sda2". Removing
> > > CMDLINE_BOOL and
> > > unconditionally setting the default value of CMDLINE to "" would
> > > clean up the
> > > Kconfig even more.
> > Note
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/co
> > mmit/?id=cbe46bd4f5104552b612505b73d366f66efc2341
> > which is already a step forward.
> >
> > I guess that default is for users selecting this option manually to
> > get
> > a first sensitive CMDLINE. But is it really worth it ?
>
> I'm not even sure if it is working as intended right now. Even without
> my changes if I use menuconfig and select CMDLINE_BOOL I end up with
> CONFIG_CMDLINE="" in the resulting .config.

I guess if the CONFIG_CMDLINE doesn't exist yet, it will get the default 
value. But if it is already there allthough empty, it will remain empty.
So yes I guess you could just drop it for this reason and the other 
reasons you said.

Christophe