On Sun, Jan 08, 2023 at 03:04:25PM +0900, Masami Hiramatsu wrote: > On Sat, 7 Jan 2023 08:22:02 -0800 > "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: > > > On Sun, Jan 08, 2023 at 12:22:15AM +0900, Masami Hiramatsu wrote: > > > On Wed, 4 Jan 2023 16:58:38 -0800 > > > "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: > > > > > > > The BOOT_CONFIG family of Kconfig options allows a bootconfig file > > > > containing kernel boot parameters to be embedded into an initrd or into > > > > the kernel itself. This can be extremely useful when deploying kernels > > > > in cases where some of the boot parameters depend on the kernel version > > > > rather than on the server hardware, firmware, or workload. > > > > > > > > Unfortunately, the "bootconfig" kernel parameter must be specified in > > > > order to cause the kernel to look for the embedded bootconfig file, > > > > and it clearly does not help to embed this "bootconfig" kernel parameter > > > > into that file. > > > > > > > > Therefore, provide a new BOOT_CONFIG_FORCE Kconfig option that causes the > > > > kernel to act as if the "bootconfig" kernel parameter had been specified. > > > > In other words, kernels built with CONFIG_BOOT_CONFIG_FORCE=y will look > > > > for the embedded bootconfig file even when the "bootconfig" kernel > > > > parameter is omitted. This permits kernel-version-dependent kernel > > > > boot parameters to be embedded into the kernel image without the need to > > > > (for example) update large numbers of boot loaders. > > > > > > I like this because this is a simple solution. We have another option > > > to specify "bootconfig" in CONFIG_CMDLINE, but it can be overwritten by > > > bootloader. Thus, it is better to have this option so that user can > > > always enable bootconfig. > > > > Glad you like it! > > > > In addition, if the help text is accurate, another shortcoming of > > CONFIG_CMDLINE is that its semantics vary from one architecture to > > another. Some have CONFIG_CMDLINE override the boot-loader supplied > > parameters, and others differ in the order in which the parameters > > are processed. > > Yes, that differences confuse us... I am glad that it is not just me. ;-) I will add words to that effect to the commit log. > > > Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > > > > Thank you! > > > > > BTW, maybe CONFIG_BOOT_CONFIG_EMBED is better to select this. > > > (or at least recommend to enable this) > > > > Like this? > > Yes! Thanks. > > > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > commit d09a1505c51a70da38b34ac38062977299aef742 > > Author: Paul E. McKenney <paulmck@xxxxxxxxxx> > > Date: Sat Jan 7 08:09:22 2023 -0800 > > > > bootconfig: Default BOOT_CONFIG_FORCE to y if BOOT_CONFIG_EMBED > > > > When a kernel is built with CONFIG_BOOT_CONFIG_EMBED=y, the intention > > will normally be to unconditionally provide the specified kernel-boot > > arguments to the kernel, as opposed to requiring a separately provided > > bootconfig parameter. Therefore, make the BOOT_CONFIG_FORCE Kconfig > > option default to y in kernels built with CONFIG_BOOT_CONFIG_EMBED=y. > > > > The old semantics may be obtained by manually overriding this default. > > > > Suggested-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> > > Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Applied, thank you! Thanx, Paul > Thank you! > > > > > diff --git a/init/Kconfig b/init/Kconfig > > index 0fb19fa0edba9..97a0f14d9020d 100644 > > --- a/init/Kconfig > > +++ b/init/Kconfig > > @@ -1379,6 +1379,7 @@ config BOOT_CONFIG > > config BOOT_CONFIG_FORCE > > bool "Force unconditional bootconfig processing" > > depends on BOOT_CONFIG > > + default y if BOOT_CONFIG_EMBED > > help > > With this Kconfig option set, BOOT_CONFIG processing is carried > > out even when the "bootconfig" kernel-boot parameter is omitted. > > > -- > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
