Mitch Bradley wrote:

Mike Rapoport wrote:

quoted

Mitch Bradley wrote:

quoted

The second topic is the hypothetical use of OFW as a HAL. That will 
not happen for several reasons.  The opposition to the idea is 
widespread and deeply held, and there are good arguments to support 
that opposition.   Furthermore, the economic conditions necessary for 
the creation of such a HAL do not exist in the ARM world, nor indeed 
in the Linux world in general.  (The necessary condition is the 
ability for one company to impose a substantial change by fiat - 
essentially a monopoly position.)

Shall we agree, then, that any further discussion of the HAL issue is 
"just for fun", and that nobody needs to feel threatened that it 
would actually happen?

I've recently worked with vendor versions of U-Boot for advanced ARM 
SoCs. There is already *huge* chunk of HAL code in those versions. And 
if there would be possibility to have callbacks into the firmware 
these chunks would only grow, IMHO.

How can there be HAL code in U-Boot unless there is already the 
possibility to have callbacks into the firmware?

Currently it aims to abstract hardware from U-Boot and reuse the same HW 
access code across operating systems and bootloaders. If this code would 
have callbacks I afraid the things would became worse.

It is not HAL if it can't be called.

quoted

quoted

The potential for "vendors breaking out of the debugging use case and 
turning it into a HAL" is miniscule, because

a) The callback is disabled by default
b) The technical challenges of the callback interface limit its 
applicability to specific "wizard user" scenarios
c) OFW is unlikely to achieve sufficient market penetration for the 
HAL thing to be worth doing


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-- 
Sincerely yours,
Mike.