On Thu, Mar 25, 2021 at 6:06 AM Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote: > > > > Le 24/03/2021 à 18:32, Rob Herring a écrit : > > On Wed, Mar 24, 2021 at 11:01 AM Christophe Leroy > > <christophe.leroy@xxxxxxxxxx> wrote: > >> > >> > >> > >> Le 09/03/2021 à 22:29, Daniel Walker a écrit : > >>> On Tue, Mar 09, 2021 at 08:47:09AM +0100, Christophe Leroy wrote: > >>>> > >>>> > >>>> Le 09/03/2021 à 01:02, Daniel Walker a écrit : > >>>>> This is a scripted mass convert of the config files to use > >>>>> the new generic cmdline. There is a bit of a trim effect here. > >>>>> It would seems that some of the config haven't been trimmed in > >>>>> a while. > >>>> > >>>> If you do that in a separate patch, you loose bisectability. > >>>> > >>>> I think it would have been better to do things in a different way, more or less like I did in my series: > >>>> 1/ Provide GENERIC cmdline at the same functionnality level as what is > >>>> spread in the different architectures > >>>> 2/ Convert architectures to the generic with least churn. > >>>> 3/ Add new features to the generic > >>> > >>> You have to have the churn eventually, no matter how you do it. The only way you > >>> don't have churn is if you never upgrade the feature set. > >>> > >>> > >>>>> > >>>>> The bash script used to convert is as follows, > >>>>> > >>>>> if [[ -z "$1" || -z "$2" ]]; then > >>>>> echo "Two arguments are needed." > >>>>> exit 1 > >>>>> fi > >>>>> mkdir $1 > >>>>> cp $2 $1/.config > >>>>> sed -i 's/CONFIG_CMDLINE=/CONFIG_CMDLINE_BOOL=y\nCONFIG_CMDLINE_PREPEND=/g' $1/.config > >>>> > >>>> This is not correct. > >>>> > >>>> By default, on powerpc the provided command line is used only if the bootloader doesn't provide one. > >>>> > >>>> Otherwise: > >>>> - the builtin command line is appended to the one provided by the bootloader > >>>> if CONFIG_CMDLINE_EXTEND is selected > >>>> - the builtin command line replaces to the one provided by the bootloader if > >>>> CONFIG_CMDLINE_FORCE is selected > >>> > >>> I think my changes maintain most of this due to the override of > >>> CONFIG_CMDLINE_PREPEND. This is an upgrade and the inflexibility in powerpc is > >>> an example of why these changes were created in the first place. > >> > >> "inflexibility in powerpc" : Can you elaborate ? > >> > >>> > >>> For example , say the default command line is "root=/dev/issblk0" from iss476 > >>> platform. And the bootloader adds "root=/dev/sda1" > >>> > >>> The result is <prepend><bootloader><append>. > >> > >> > >> I'm still having hard time understanding the benefit of having both <prepend> and <append>. > >> Could you please provide a complete exemple from real life, ie what exactly the problem is and what > >> it solves ? > > > > It doesn't matter. We already have both cases and 'extend' has meant either one. > > > > What someone wants is policy and the kernel shouldn't be defining the policy. > > > > Ok, so you agree we don't need to provide two CMDLINE, one to be appended and one to be prepended. Well, I wasn't thinking about that part of it, but yes as long as no arch currently needs that. > Let's only provide once CMDLINE as of today, and ask the user to select whether he wants it appended > or prepended or replacee. Then no need to change all existing config to rename CONFIG_CMDLINE into > either of the new ones. > > That's the main difference between my series and Daniel's series. So I'll finish taking Will's > comment into account and we'll send out a v3 soon. Great. Rob
