Mitch Bradley wrote:
Mike Rapoport wrote:
Mitch Bradley wrote:
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.
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.
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