Re: [RFC] Generic access to firmware environment variables

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> On Wed, 10 Apr 2002 20:42:31 +0200, Jan-Benedict Glaw <jbglaw@lug-owl.de> said:

  Jan-Benedict> Hi!  I've developed a driver to access environment
  Jan-Benedict> variables on Alpha computers from userspace through
  Jan-Benedict> procfs some time ago. These days, I updated the
  Jan-Benedict> driver. While doing this, I also looked at other
  Jan-Benedict> architectures; some of them also do have some kind of
  Jan-Benedict> environment variables in firmware:

  Jan-Benedict> 	Alphas - SRM firmware SGI Workstations - ARCS
  Jan-Benedict> firmware MIPS/ITE-Boards - PMON m68k/MAC - ?? (info is
  Jan-Benedict> placed into a "bootinfo" struct) IA64 - (_seems_ to
  Jan-Benedict> know about environment...)

  Jan-Benedict> They all access environment variables either by name,
  Jan-Benedict> or by an internally handles number. For Alpha, I've
  Jan-Benedict> (now) implemented both, access by name (if variable
  Jan-Benedict> name is known/described) and access by generic number.

  Jan-Benedict> I think it would be useful to have something like this
  Jan-Benedict> for other architectures as well. So I'm currently
  Jan-Benedict> thinking about implementing a base driver (like
  Jan-Benedict> parport does) and additional modules to implement
  Jan-Benedict> machine/architecture specific access methode (like
  Jan-Benedict> parport_pc).

  Jan-Benedict> It's easy to code, so what do you think of this?

On EFI platforms, there is /proc/efi/vars.  The module was written by
Matt Domsch <Matt_Domsch@Dell.com>.  EFI is used on ia64 and x86
servers.  Note that EFI variables can contain arbitrary binary data,
not just text strings.

	--david