BootX enhancement request

Benjamin Herrenschmidt bh40 at
Tue Aug 24 19:02:29 EST 1999

On Tue, Aug 24, 1999, Paul Mackerras <paulus at> wrote:

>Yep.  There are two problems at the moment, which I should get off my
>butt and fix. :-)
>The first is that the current machines use a different structure for
>nvram, based on the CHRP spec, which means that just using a fixed
>offset in nvram doesn't work.  In fact it seems like macos adds a OF
>property with a really strange encoding to store arbitrary bits of
>information for the device drivers for arbitrary devices.
>The second is that macos is now using mode numbers > 20.  I haven't
>worked out the correspondence yet.

MacOS no longer relies on the nvram setting. Video drivers are free to
put whatever they want in their own device tree node, and usually store
an nvram value for the mode there, but this is proprietary and depends on
the driver. MacOS itself now stores the various infos in a preferences
file. The old "Monitors" control panel still updates the old pram
location with a mode value but the meaning is not guaranteed (can be
driver specific).

           Perso. e-mail: <mailto:bh40 at>
           Work   e-mail: <mailto:benh at>
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