On Wed, Aug 26, 2015 at 02:53:35AM +0100, Ken Moffat wrote:
> On Tue, Aug 25, 2015 at 07:29:56PM -0400, Wayne Sallee wrote:
> >
> >
> > On 08/25/2015 07:20 PM, Ken Moffat wrote:
> > >On Tue, Aug 25, 2015 at 05:54:05PM -0400, Wayne Sallee wrote:
> > >>Here are some dd commands:
> > >>
> > >>Read the bios
> > >>dd if=/dev/mem bs=1 skip=983040 count=65535 of=bios.bin
> > >>
> > >>Read the bios settings
> > >>dd if=/dev/nvram of=nvram.bin
> > >You have3 /dev/nvram ? On a quick check (desktop-type box running
> > >as a server, and my netbook) I do not have /dev/nvram.
> > >
> > >ĸen
> >
> > Inside a terminal as root enter:
> > ls /dev/nvram
> >
> > Does nothing show up?
> >
> > Wayne Sallee
> > [email protected]
>
> I do not have such a device. So, no.
>
> ĸen
After deciding that my current kernel bisection appeared to be
'good' (see blfs-dev), I googled for /dev/nvram. That found
http://cateee.net/lkddb/web-lkddb/NVRAM.html
which tells me this about CONFIG_NVRAM :
"If you say Y here and create a character special file /dev/nvram
with major number 10 and minor number 144 using mknod ("man mknod"),
you get read and write access to the extra bytes of non-volatile
memory in the real time clock (RTC), which is contained in every PC
and most Ataris. The actual number of bytes varies, depending on the
nvram in the system, but is usually 114 (128-14 for the RTC)."
It also says "Note however that most NVRAM space in a PC belongs to
the BIOS and you should NEVER idly tamper with it."
So, on your machine that offset appears to provide the data.
Whether it does so on other machines needs to be determined -
perhaps you have a reference to explain that it is generally correct
? In any case, most people probably do not need this config
setting.
ĸen
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the right direction.
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