[OpenBIOS] next-property

[Mark Cave-Ayland]

On 03/01/14 19:16, Olivier Danet wrote:

Hi Olivier,

> You are right.
> I tried on an Ultra 10 with OpenBoot 3.12.
>
> next-property returns nothing when the property is unknown and also when
> the property is the last one.
> This contradicts Sun own documentation "Writing FCode 3.x Programs".

Hmmmm. Is there anything in the IEEE1275 errata about this?

> Puzzled, I tried then on a Apple iBook G3 :
> dev screen
> " <something>" active-package next-property
>
> This laptop returns :
> - true and a forth string when the property is not the last one
> - true and "0 0" when the property is the last one
> - false when the property does not exist.
>
> Anyway, whatever method is chosen (return nothing, return zero...),
> OpenBIOS forth and/or C code ("opb_nextprop()") should be modifed to
> avoid page faults.

Yes indeed. The OpenBIOS Forth string to C string implementation returns 
NULL if the length is 0 which has caught me out a few times. The trick 
I've done, particularly in the filesystem drivers, is to do something 
like the following where required:

if (str == NULL) {
     return "";
}

BTW you never answered about which version of NetBSD you were trying to 
boot?


ATB,

Mark.