[RFC] new ATAG for NVS?

[RFC] new ATAG for NVS?

[Vitaly Wool]

Hi,

we're currently thinking over how to pass over the data from
non-volatile storage to a kernel driver. I've seen some examples in
kernel that actually read out the NV data to userspace and then supply
it as firmware to the driver that requests it. However, if NV data is
anyway processed by the bootloader, isn't it reasonable to pass it
over to kernel via ATAG? I'm eager to come up with a patch that
introduces new ATAG for that.

Thanks,
   Vitaly

[RFC] new ATAG for NVS?

[Linus Walleij]

2010/8/13 Vitaly Wool <vitalywool@gmail.com>:

> we're currently thinking over how to pass over the data from
> non-volatile storage to a kernel driver. I've seen some examples in
> kernel that actually read out the NV data to userspace and then supply
> it as firmware to the driver that requests it. However, if NV data is
> anyway processed by the bootloader, isn't it reasonable to pass it
> over to kernel via ATAG? I'm eager to come up with a patch that
> introduces new ATAG for that.

What kind of data is it and where is it stored?

I remember seeing some people adding extensions to e.g. the
RTC drivers to read out the NVRAM found in some RTC chips,

Isn't it possible to just export the symbol from e.g. the RTC driver
and provide it in a header file like include/linux/rtc/foo.h
int get_foo_nvram_array(char *ramcontents, maxlength);
or something like that?

Or is there some other restriction like reading it is slow or
in some security context so that only the bootloader can
access it?

Yours,
Linus Walleij