L4Re halts at boot, waiting for console input

Adam Lackorzynski adam at os.inf.tu-dresden.de
Sat Nov 28 00:47:53 CET 2015


On Thu Nov 26, 2015 at 11:12:22 +0200, Arttu Pulli wrote:
> Hello hackers,
> the subject line summarizes my problem pretty well. To expand, the halting
> happens first when Ned begins booting the user space services defined in the
> modules.list config, after it has loaded the Lua config script file. First I
> thought that my setup is just wrong, but feeding some amount of newlines
> through the serial console causes the boot to continue normally. The system
> is still waiting for input during this, though, as can be seen from the fact
> that the boot will go forward to starting Io with a couple of newlines, then
> it halts after that again, then newlines start my own user space modules,
> the system halting between every module if no input is given.
> This only happens on warm boots. When powering the board for the first time,
> the boot goes all the way to the finish without any user input.
> I'm using a custom i.MX6Q based board.
> So, with that background, my question is is there some general place where
> this kind of behaviour can be configured? Or is it just that my setup is
> somehow broken, and this is not any kind of feature of Fiasco.OC/L4?

That's definitely not a feature. My first guess would be that this
behavior could be UART related. Maybe there's an interrupt storm that is
stopped by giving some input. You can check this by enabling IRQ logging
in extended logging in jdb.

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

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