Re: [PATCH] char drivers: Ram oops kernel configuration parameters

[Mandeep Singh Baines <msb@chromium.org>]

Marco Stornelli (marco.stornelli@gmail.com) wrote:
> 2011/6/24 Mandeep Singh Baines <msb@chromium.org>:
> > On Thu, Jun 23, 2011 at 2:33 PM, Greg KH <gregkh@suse.de> wrote:
> >> On Thu, Jun 23, 2011 at 01:43:49PM -0700, Sergiu Iordache wrote:
> >>> On Thu, Jun 23, 2011 at 12:59 PM, <Valdis.Kletnieks@vt.edu> wrote:
> >>> > On Thu, 23 Jun 2011 11:36:00 PDT, Sergiu Iordache said:
> >>> > > Ramoops currently has module parameters for setting the configuration
> >>> > > variables (ram start, ram size and dump oopses). This makes it difficult to
> >>> > > configure when the module is compiled as a builtin.
> >>> >
> >>> > Can't you add 'ramoops.ram_start=128M ramoops.ram_size=64M' or similar
> >>> > to your kernel cmdline?
> >>>
> >>> You can but the problem is that when you're using the module as a
> >>> builtin managing the command line is harder than managing Kconfig
> >>> files. Instead of having different platform dependent config files
> >>> (which already exist in most of the cases) under source control you
> >>> would have to have different scripts which run the kernel with
> >>> different parameters.
> >>
> >> Then why not make the sysfs files writable?
> >>
> >
> > We do use sysctl and sysfs for most of our tuning stuff.
> >
> > But in this case, you wouldn't be able to write the sysfs file until
> > late in boot
> > so an early crashed would be lost.
> >
> > Our command-line is pretty generic across targets. Even across archs.
> >
> 
> Maybe using platform data? With archs with device tree support can be easy.
> 

FDT is a good idea. Thanks.

I guess for x86, we could add a file to drivers/platform/x86 to register
a device.

> Marco