Re: NetBSD on PDAs/mobile phones?

[Peter Tworek <tworaz666%gmail.com@localhost>]

On 08/24/2011 08:00 PM, Andy Ruhl wrote:
> On Wed, Aug 24, 2011 at 10:57 AM, Mayuresh <mayuresh%acm.org@localhost> wrote:
>> I don't know whether this is an odd question to ask.
>>
>> Considering emphasis of NetBSD on running on many platforms, I'm curious
>> whether it runs on any mobile phone / PDA devices.
>>
>> I was specifically interested in Nokia N900, whose native OS is Maemo
>> (Linux).
> It's not an odd question, it's just a question of time and effort probably.
>
> For most modern machines, if you can access the hardware or bootloader
> to load a kernel, and the CPU archtecture and basic hardware are
> known, it can probably boot NetBSD eventually.
>
> That said, not much work has been done in this area. There might be a
> reason for that.
>
> Andy
AFAIK, the CPU used by N900 - OMAP3 is supported by NetBSD to some
degree. The initial obstacle is probably NOLO. From what I understand
it's very linux specific and there is no documentation on how it works.
Even if we knew how to boot netbsd kernel using NOLO, there is a problem
of getting any kind of output from it. Serial port is probably the best
way, but in case of N900 this will require some hardware hacking. Of
course the initial porting work can be done using qemu, but there is no
grantee that the kernel booting on the emulator will actually work on
the real hardware. Once the kernel boots there is still a matter of
writing device drivers for all the peripherals. N900 is not as open as
it seems at first glance, many of the phone components are missing
documentation. As an example battery charger module is completely
undocumented and most of the charging logic is hidden in a closed source
userland componrent, bme.

In short, porting NetBSD to N900 is certainly doable, but would require
lots of free time. The device isn't as open as it seems and is not even
fully supported by the mainline linux kernel. If you're really
interested in having NetBSD mobile phone in your pocket OpenMoko seems
like the best candidate.

As for a NetBSD PDA I've recently found NanoNote. I really like it's
form factor and it seems that getting it fully supported by NetBSD
should be easy. I got NetBSD kernel running on qemu-jz which emulates
the same hardware as NanoNote uses. The only thing that keeps me from
buying the device and finishing the port is the lack of any kind of
network connectivity and only 32MB of RAM. With such specs buying old HP
Jornada 720/728 is probably a better idea.

/ptw