Re: persistence of kernel object attribute ??

From: Richard B. Johnson
Date: Thu Apr 15 2004 - 13:42:25 EST


On Thu, 15 Apr 2004, Smart, James wrote:

>
> I've been looking at everything I can find, asked a few questions, and don't
> have an answer to the following issue.
>
> I have a driver that wants to export attributes per instance. I'd like the
> ability for the user to modify an attribute dynamically (sysfs works well) -
> but I'd like the new value to be persistent the next time the driver
> unloads/loads or the system reboots. I don't want to have to update
> constants in source and recompile the driver. I'm looking for something
> similar (cringe!) to the MS registry. Is there a facility available to
> kernel objects to allow for persistent attributes to be set/retrieved? If
> not, any recommendations on how to implement this ?
>
> -- james
>

Make a program that executes upon startup, using the Sys-V startup
convention. That program interfaces with your driver using a standard
ioctl() call. It can send or receive anything it wants, which it can
get or put to any accessible file-system.

FYI this is the standard Unix/Linux way. You'd be surprised the
large number of users who haven't got a clue about how Unix starts
up. They vaguely remember something about "init" and that's it.
To refresh your memory, look in /etc/rc.d and the sub-directories
for each run-level. Believe me, you don't want or need a "registry".
Just put a link to your startup-script in there.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.24 on an i686 machine (5596.77 BogoMips).
Note 96.31% of all statistics are fiction.


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