About l4linux debug method

Adam Lackorzynski adam at os.inf.tu-dresden.de
Tue Jan 17 23:10:31 CET 2017


On Mon Jan 16, 2017 at 17:40:11 +0800, li94575 wrote:
> At 2017-01-15 19:14:36, "Adam Lackorzynski" <adam at os.inf.tu-dresden.de> wrote:
> >Hi,
> >
> >On Sun Jan 08, 2017 at 22:54:31 +0800, li94575 wrote:
> >> At 2016-12-15 07:45:49, "Adam Lackorzynski" <adam at os.inf.tu-dresden.de> wrote:
> >> >
> >> >On Wed Dec 14, 2016 at 21:53:48 +0800, li94575 wrote:
> >> >> At 2016-12-13 07:01:44, "Adam Lackorzynski" <adam at os.inf.tu-dresden.de> wrote:
> >> >> >Hi,
> >> >> >
> >> >> >On Sun Dec 11, 2016 at 20:45:11 +0800, li94575 wrote:
> >> >> >> I have faced a thorny problem, l4linux died occasionally after running into the command line, and there are no errors displayed, pressing the ESC key also cannot enter fiasco jdb-mode. I don't know what caused the problem, can someone provide some methods to help locating this problem?
> >> >> >
> >> >> >Just do clarify, does it happen right after L4Linux booted in the
> >> >> >command line or are you running anything and then, when this is
> >> >> >finished, it stops responding?
> >> >> >Did ESC work before this happens?
> >> >> >Does L4Linux go on running, i.e. is it just serial input that stops
> >> >> >working? (Do something like while sleep 1; do date; done)
> >> >> >Unfortunately there can be a couple of reasons, so we need to narrow
> >> >> >this a bit.
> >> >> >
> >> >> L4Linux has been dead completely, all peripheral interrupts are no longer responded. The ESC key can work before this happens.
> >> >> Actually I have tried starting Android on L4Linux, This phenomenon can appear anywhere in the start-up and running time of Android. Android logcat also has no error tips£¬it seems CPU suddenly stops working.
> >> >
> >> >Good that you mention Android. Are you passing through hardware devices?
> >> >With your description is may be that the Linux is doing something that
> >> >it should better not do as it's not in posession of the whole platform,
> >> >but it thinks it is.
> >> >
> >> I have passed through all the necessary hardware devices (fb, input, mmc). We are using l4re--rev58 and l4linux3.10, I wonder if this release itself has some minor problems, and if it is, can you tell me what are the possible bugs, that you have fixed them later.
> >
> >Frankly, L4Linux-3.10 is pretty old by now and I'm sure there are fixes
> >in the meantime, however it's hard to pinpoint to particular issues.
> >One cause of your issues could be DMA, i.e. DMA going wrong and thus
> >overwriting stuff in memory. But there could be other reasons too.
> >To isolate, did you try to just, for example, use MMC and run heavy
> >load on that and see whether this is stable or not?
> >
> Thank you very much for your answer.  I have tried to update l4re  to rev67, 
> and make some adjustments for l4linux3.10 accordingly, which relates to the
> new arm error codes. Now l4linux3.10 can run well, the abnormal crash has 
> no longer appeared. I guess it could have been a bug in the rev58 kernel that caused the crash.

Great that is works now! :)



Adam




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