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. Rob
