[PATCH v2 3/3] fs: add linux_rootarg 'root=mmcblkXpN' support

[Marco Felsch]

On 21-05-09 15:32, Roland Hieber wrote:
> On Thu, May 06, 2021 at 06:26:16PM +0200, Marco Felsch wrote:
> > Since commit fa2d0aa96941 ("mmc: core: Allow setting slot index via
> > device tree alias") the linux kernel supports stable mmc device names.
> > Barebox has stable names since years so now we can connect both which
> > allows us to pass 'root=mmcblkXpN' as argument for the cmdline. Note: it
> > is crucial that the kernel device tree and the barebox device tree uses
> > the same mmc aliases.
> > 
> > This patch adds the support to store the above cmdline as linux_rootarg
> > if enabled. The partuuid is now used as fallback since it is not as
> > unique as the mmcblkXpN scheme. It is added as build option since the
> > system integrator needs to check if the used kernel contains the above
> > commit.
> > 
> > Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> > ---
> > v2:
> > - improved Kconfig deps
> > - improved Kconfig help message
> > - minimal get_linux_mmcblkdev() simplifications
> > 
> >  common/Kconfig | 21 +++++++++++++++++++++
> >  fs/fs.c        | 42 ++++++++++++++++++++++++++++++++++++++----
> >  2 files changed, 59 insertions(+), 4 deletions(-)
> > 
> > diff --git a/common/Kconfig b/common/Kconfig
> > index 6b3c1701be..5815ea06f0 100644
> > --- a/common/Kconfig
> > +++ b/common/Kconfig
> > @@ -700,6 +700,27 @@ config FLEXIBLE_BOOTARGS
> >  	  to replace parts of the bootargs string without reconstructing it
> >  	  completely.
> >  
> > +config MMCBLKDEV_ROOTARG
> > +	bool
> > +	prompt "Support 'root=mmcblkXpN' cmdline appending"
> > +	depends on FLEXIBLE_BOOTARGS
> > +	depends on MCI
> > +	depends on OFTREE
> > +	help
> > +	  Enable this option to append 'root=mmcblkXpN' to the cmdline instead
> > +	  of 'root=PARTUUID=XYZ'. Don't enale this option if your used linux
> > +	  kernel don't contain commit [1]. The first linux kernel release
> 
> Nit: s/enale/enable/; s/don't/doesn't/ (can probably fixed during git-am).

Thanks, send a v3 since I noticed a untested an now fixed bug.

Regards,
  Marco