L4Android and L4Linux parallel on an i.MX53

Adam Lackorzynski adam at os.inf.tu-dresden.de
Sun Apr 22 15:58:41 CEST 2012

On Tue Apr 17, 2012 at 12:09:36 +0200, Tobias Fink wrote:
> > Do I understand correctly that L4Linux talks successfully to the UART?
> > (You're only showing parts of the iol4lx_tf.io file?) Then this would be
> > a pure Linux thing. Something like this: prog </dev/ttyLv1 >/dev/ttyLv1 2&>1
> I'm showing the full .io file. I have just used another cfg (without
> starting the L4Linux) for testing.
> Well L4Linux talks to the UART that it detects automatically.
> A Linux kernel sees that one as follows:
> [    0.969085] serial8250.2: ttyS2 at MMIO 0x49020000 (irq = 74) is a ST16654
> L4 says during startup:
> SERIAL ESC: allocated IRQ 74 for serial uart
> and L4Linux:
> console [ttyLv0] enabled
> ..
> ttyLv0 at MMIO 0x1 (irq = 210) is a L4
> What I'm trying to do is to use another UART to communicate with a
> second L4Linux on top of L4.
> This is the UART I'm trying to use
> [    0.598999] serial8250.0: ttyS0 at MMIO 0x4806a000 (irq = 72) is a ST16654
> (note that there was a mistake in my .io file where the other UART was
> initialized. I changed that without any effect).
> So as I understand it I have to initialize the second interface and
> give it to the second L4Linux when booting with "console=....".

Early in L4Linux's boot-up messages there's a device scan, i.e. a list
of all resources L4Linux is getting from io. Is 0x4806a000 in this list?
io is also outputting device trees for each client and for the whole
hardware, check that the resources of the serial device are also there
(use more -v's for io if necessary).

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

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