Kernel for olpc-1.75

Kernel for olpc-1.75

[Pavel Machek]

Hi!

I broke installation on olpc-1.75, and I guess its time for it to
start running self-compiled kernel. (It still boots if I hold right
game key, but I can no longer control backlight. It does not boot at
all by default.)

AFAICT, olpc.fth and zImage in the boot/ directory of USB disk should
do the trick.

Unfortunately, 3.0 based kernels no longer compile with current tools,
so I tried this version (3.6 based).

commit 2a873e0e3681412ccc82a646630ffaf119d36af0
Author: Chris Ball <cjb@laptop.org>
Date:   Wed Aug 22 18:51:58 2012 -0400

    Revert "ARM: mmp: Send decompress and debug output to UART3
    instead of UART2
    
    This reverts commit 8fb8e2ccffd5387c4a5e4e5294270fa61716eb51.

Unfortunately, no output at all with
arch/arm/configs/xo_175_defconfig.

I tried replacing all =m's in .config with =y, but still no output.

Is there more recent kernel to work with? Is 2a87... somehow buggy?
Did I miss some critical step? Will recent mainline run on olpc
unmodified?

Thanks,
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: Kernel for olpc-1.75

[Daniel Drake]

Hi Pavel,

On Sat, Jun 7, 2014 at 11:53 PM, Pavel Machek <pavel@ucw.cz> wrote:
> I broke installation on olpc-1.75, and I guess its time for it to
> start running self-compiled kernel. (It still boots if I hold right
> game key, but I can no longer control backlight. It does not boot at
> all by default.)
>
> AFAICT, olpc.fth and zImage in the boot/ directory of USB disk should
> do the trick.
>
> Unfortunately, 3.0 based kernels no longer compile with current tools,
> so I tried this version (3.6 based).

Sorry but OLPC never progressed beyond shipping 3.0 on this hardware,
and low-level development only really happens in maintenance mode at
the moment.

We did almost get a newer version working, but it had some unresolved
issues that prevented us from shipping it to users. I'm not sure of
the state of that arm-3.6 branch you are trying but I don't see
anything wrong in your process. I would try early printascii() calls
and a serial cable next.

Mainline won't run on the machine in any kind of usable state without
quite a bit of work on drivers and DT (which comes from the firmware).
I did once start on that but didn't manage to get even the initial
easy patches past the Marvell maintainers :(

Daniel

Re: Kernel for olpc-1.75

[Pavel Machek]

Hi!

> On Sat, Jun 7, 2014 at 11:53 PM, Pavel Machek <pavel@ucw.cz> wrote:
> > I broke installation on olpc-1.75, and I guess its time for it to
> > start running self-compiled kernel. (It still boots if I hold right
> > game key, but I can no longer control backlight. It does not boot at
> > all by default.)
> >
> > AFAICT, olpc.fth and zImage in the boot/ directory of USB disk should
> > do the trick.
> >
> > Unfortunately, 3.0 based kernels no longer compile with current tools,
> > so I tried this version (3.6 based).
> 
> Sorry but OLPC never progressed beyond shipping 3.0 on this hardware,
> and low-level development only really happens in maintenance mode at
> the moment.

:-(.

> We did almost get a newer version working, but it had some unresolved
> issues that prevented us from shipping it to users. I'm not sure of
> the state of that arm-3.6 branch you are trying but I don't see
> anything wrong in your process. I would try early printascii() calls
> and a serial cable next.

Ok, that's more debugging than I can do at the moment, given my
inexperience with this hardware. I guess I should really try arm-3.0
branch...

> Mainline won't run on the machine in any kind of usable state without
> quite a bit of work on drivers and DT (which comes from the firmware).
> I did once start on that but didn't manage to get even the initial
> easy patches past the Marvell maintainers :(

Hmm, that's sad... but perhaps Marvell maintainers improved in the
meantime?

Would you have working zImage binary I could use for experiments?

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: Kernel for olpc-1.75

[Pavel Machek]

Hi!

> On Sat, Jun 7, 2014 at 11:53 PM, Pavel Machek <pavel@ucw.cz> wrote:
> > I broke installation on olpc-1.75, and I guess its time for it to
> > start running self-compiled kernel. (It still boots if I hold right
> > game key, but I can no longer control backlight. It does not boot at
> > all by default.)
> >
> > AFAICT, olpc.fth and zImage in the boot/ directory of USB disk should
> > do the trick.
> >
> > Unfortunately, 3.0 based kernels no longer compile with current tools,
> > so I tried this version (3.6 based).
> 
> Sorry but OLPC never progressed beyond shipping 3.0 on this hardware,
> and low-level development only really happens in maintenance mode at
> the moment.

Ok, wip-3.0 branch boots on the hardware. Good so far... but
touchpad does not work... If you have any idea about that...)

Redhat update kernel (yes, I made a mistake of installing that)
has broken backlight controls, and only boots in development
mode. Ideas here would be welcome, too...

> We did almost get a newer version working, but it had some unresolved
> issues that prevented us from shipping it to users. I'm not sure of
> the state of that arm-3.6 branch you are trying but I don't see
> anything wrong in your process. I would try early printascii() calls
> and a serial cable next.
> 
> Mainline won't run on the machine in any kind of usable state without
> quite a bit of work on drivers and DT (which comes from the firmware).
> I did once start on that but didn't manage to get even the initial
> easy patches past the Marvell maintainers :(

Ok, let me try to get machine into semi-working state, and
then I can think about updating kernels...
						Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html