Re: [PATCH v2] char drivers: Ram oops/panic logger

[Jamie Lokier <jamie@shareable.org>]

Marco Stornelli wrote:
> Il 13/03/2010 00:31, Jamie Lokier ha scritto:
> > That'd be fine if the kernel link scripts choose the address, as long
> > as it's consistent between different compiles and similar
> > configurations.  That'd be a bit simpler than the admin having to know
> > the memory map well enough to choose an address.
> > 
> > -- Jamie
> > 
> 
> I agree, but the bootloader should be aware of it. I mean, usually
> bootloaders at boot, reset the RAM, so you have to tell to the
> bootloader that you are using a piece of RAM as persistent RAM, for
> example U-Boot has got a specific option CONFIG_PRAM. I don't know if
> all the process can be completely transparent to the admin in all
> situations.

Sometimes you can't change the bootloader (they don't always come with
source code).  Or you could, but you don't want to risk it (there
isn't always a way to recover if you break it).

Obviously then the feature is only useful when the bootloader doesn't
clear all the RAM :-)

On slow boards in consumer devices, they sometimes avoid clearing the
RAM because that adds measurable boot time.

-- Jamie