EV-64260-BP & GT64260 bi_recs
geert at linux-m68k.org
Mon Mar 25 06:38:42 EST 2002
On Sun, 24 Mar 2002, Val Henson wrote:
> On Sun, Mar 24, 2002 at 01:20:48PM +0100, Benjamin Herrenschmidt wrote:
> > We define a special BI_DEVICE type of bi_rec that represents
> > a HW device for which the firmware provides some informations. Since
> > the firmware is free to provide whatever informations it want (that
> > set is not fully defined), the content of the BI_DEVICE record is itself
> > a list of bi_recs.
> > The "standard" kernel only define a few BI_DEV_TYPE's (like PCI,
> > 4xx OCP, 8xx OCP). Drivers define attributes they can read from the
> > BI_DEVICE (4xx ethernet can read a HW eth adress for example).
> > Board vendors are free to provide additional information in the
> > BI_DEVICE, and add the ability to the driver (patches welcome) to
> > make good use of that information ;) (Could be, for example, wiring
> > of the PHY since it may not use MII, etc...).
> > What do you think ?
> I had an amazing and brilliant insight (which I'm sure everyone else
> has already had). :) The kernel just ignores bi_recs it doesn't
> understand. Really, you don't need any BI_DEV_TYPE's for non-core
> kernel code - just a type that the kernel is guaranteed never to use
> for any other bi_rec type.
BTW, I just thought of something different: some people want to keep data
stored in bi_recs for later use, after the initialization of the kernel. What
about a new tag to mark data that is to be copied and stored for later use?
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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