proprietary firmware
Wolfgang Spraul
wolfgang at openmoko.com
Fri Feb 8 02:32:16 CET 2008
Dear Community,
Some of our chips or chipsets contain proprietary firmware in flash
memory. For example, in GTA02 these include the Wi-Fi, GPS, and GSM
chipsets.
Ideally, we would have liked to use chipsets for which even the
firmware code would be free, but they don't exist right now.
So we accepted proprietary firmware, as long as it was in flash or ROM.
Then we ran into problems when bugs were found in the firmware, and we
wanted to update handsets out in the field.
The vendors would give us firmware updates and reflashing tools, but
they wouldn't let us redistribute those tools to our users. We asked
for special licenses to allow us to distribute those flashing tools to
our users, and got them in some cases, after months of licensing
negotiations.
Next we discovered that those reflashing tools had further issues: for
example, they would only allow loading cryptographically signed
firmware into the chipset flash memory. The tools do this because
vendors are worried that people would disassemble, patch, and
reassemble the firmware, triggering regulatory reclassification of
their chipsets (software controlled radio).
Furthermore, we see that for upcoming chipsets, vendors are switching
from storing the firmware in flash memory to loading the firmware into
RAM at run time. One reason for this is that RAM needs less power and
is cheaper. In this case the firmware, whether original or updated,
has to be loaded each time the device boots, requiring that the binary-
only, restrictively licensed firmware updater be included in the
OpenMoko distribution.
This got quite frustrating, until we met Richard Stallman last
weekend. And he cleared it up for us rather quickly :-)
He suggested we treat any chipset with proprietary firmware as a black-
box, a circuit. He suggested we ignore the firmware inside. If the
firmware is buggy and the vendor needs the ability to update the
firmware, we instead ask the vendor to reduce the firmware to the bare
minimum, so that it can be very simple and bug free, and move the rest
of the logic into the GPL'ed driver running on the main CPU. This way
we completely avoid the issue of distributing proprietary firmware
updates and binary firmware updaters with restrictive licensing that
load only cryptographically signed firmware.
We liked his advice. It speeds up our decision making and allows us to
focus on what we do best: Developing Free Software that is available
in full source code, running on the main CPU, that we and anyone else
can modify and optimize. There are downsides: We will no longer offer
reflashing tools to update proprietary firmware, under any license.
For critical firmware bugs, we will accept returns, or in some cases
fix the bug in-house.
We will push vendors to simplify the functionality of their
proprietary firmware, so we can implement more of this on the main CPU
as Free Software. Maybe some vendors will even open up firmware for
Free Software development, that would be the ideal outcome we are
working towards.
We hope this helps clarify OpenMoko's current position on proprietary
firmware: Ignore them while they stay inside of a chip or chipset, and
refuse to touch them. Focus on what Free Software can do.
Feedback and comments are always very welcome.
Best Regards,
Wolfgang
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