Re: Missing dimm-info properties in openbios ?

[BALATON Zoltan]

On Wed, 19 Mar 2025, Andrew Randrianasulu wrote:
> I was reading NetBSD's
>
> sys/arch/macppc/macppc/memory.c
>
> and there is comment:
>
> *<---->The EEPROMs for Serial Presence Detect don't show up in the
> * <--->OpenFirmware tree, but their contents are available through the
>
> * <--->"dimm-info" property of the "/memory" node.  To make the
> * <--->information available, we fake up an I2C bus with EEPROMs
> * <--->containing the appropriate slices of the "dimm-info" property.
>
> But I can't find "dimm-info" in openbios source tree ?
>
> Is it simply not implemented?

I think OpenBIOS knows nothing about SPD and Mac i2c so it won't look at 
them. It gets memory size from fw_cfg which it adds to /memory node and 
that's it. Does NetBSD work on g3beige? You can try that with the Apple 
ROM then and see if that works.

> Reason to ask: NetBSD/macppc only can be booted with 256mb ram or less in
> Qemu.

Does it use SPD for that? Most OSes just look at the /memory node as 
it's simpler to get memory size from there than parsing SPD data.

Regards,
BALATON Zoltan