On Thu, 27 Feb 2020 20:50:19 -0800
Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
> Hi,
> A few more comments for you:
>
> On 2/26/20 11:25 PM, Masami Hiramatsu wrote:
> > Update boot configuration documentation.
> >
> > - Not using "config" abbreviation but configuration or description.
> > - Rewrite descriptions of node and its maxinum number.
> > - Add a section of use cases of boot configuration.
> > - Move how to use bootconfig to earlier section.
> > - Fix some typos, indents and format mistakes.
> >
> > Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > ---
> > Documentation/admin-guide/bootconfig.rst | 172 +++++++++++++++++++-----------
> > Documentation/trace/boottime-trace.rst | 2
> > 2 files changed, 112 insertions(+), 62 deletions(-)
> >
> > diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin-guide/bootconfig.rst
> > index cf2edcd09183..4bac98250bc0 100644
> > --- a/Documentation/admin-guide/bootconfig.rst
> > +++ b/Documentation/admin-guide/bootconfig.rst
> > @@ -11,19 +11,98 @@ Boot Configuration
> > Overview
> > ========
> >
> > -The boot configuration expands the current kernel command line to support
> > +Boot configuration expands the current kernel command line to support
> > additional key-value data when booting the kernel in an efficient way.
>
> maybe s/when/while/
Ah, right.
>
> > -This allows administrators to pass a structured-Key config file.
> > +This allows administrators to pass a structured-Key configuration file
> > +as a way to supplement the kernel command line to pass system boot parameters.
> >
> > -Config File Syntax
> > -==================
> > +Compared with the kernel command line, the boot configuration can provide
> > +scalability (up to 32 KiB configurations), readability (structured
>
> This makes it sound like bootconfig supports 32 thousand configurations, but
> (I think) it allows up to 32 KiB of configuration data.
OK, I'll add "data".
>
> > +configuration with comments) and compact expression of option groups.
> > +
> > +When to Use the Boot Configuration?
> > +-----------------------------------
> > +
> > +The boot configuration supports kernel command line options and init daemon
> > +boot options. All sub-keys under "kernel" root key are passed as a part of
> > +kernel command line [1]_, and one under "init" root key are passed as a part
>
> ones {or those}
OK.
>
> > +of init command line. For example, ::
> > +
> > + root=UUID=8cd79b08-bda0-4b9d-954c-5d5f34b98c82 ro quiet splash console=ttyS0,115200n8 console=tty0
> > +
> > +This can be written as following boot configuration file.::
> > +
> > + kernel {
> > + root = "UUID=8cd79b08-bda0-4b9d-954c-5d5f34b98c82" # nvme0n1p3
> > + ro # mount rootfs as read only
> > + quiet # No console log
> > + splash # show splash image on boot screen
> > + console = "ttyS0,115200n8" # 1st console to serial device
> > + console += tty0 # add 2nd console
> > + }
> > +
> > +If you think that kernel/init options becomes too long to write in boot-loader
> > +configuration file or want to comment on each options, you can use this
>
> on each option,
Oops, OK.
>
> > +boot configuration. If unsure, you can still continue to use the legacy
> > +kernel command line.
> > +
> > +Also, some subsystem may depend on the boot configuration, and it has own
> > +root key. For example, ftrace boot-time tracer uses "ftrace" root key to
> > +describe their options [2]_. In this case, you need to use the boot
>
> its
OK
Thank you!
>
> > +configuration.
> > +
> > +.. [1] See :ref:`Documentation/admin-guide/kernel-parameters.rst <kernelparameters>`
> > +.. [2] See :ref:`Documentation/trace/boottime-trace.rst <boottimetrace>`
>
>
> --
> ~Randy
>
--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>
