Minimal requirements to run L4linux using only a serial console
Masti Ramya Jayaram
rmasti at inf.ethz.ch
Sat Aug 30 11:18:32 CEST 2014
I replied earlier to the list but I guess I messed it up a bit. Your tip on the polling turned out to be really helpful. I basically changed the type of serial_esc in kernel/fiasco/src/kern/config.cpp from SERIAL_ESC_IRQ to SERIAL_ESC_NOIRQ and it works! It would be great if you can elaborate on the difference (I am guessing the latter uses a poll based system but more explanation would be great).
I was even able to run l4 and fiasco on the actual SCC hardware and get the UART RX to work. So thanks a ton for the tip! :)
From: Martin Schröder [mschroeder at web.de]
Sent: 29 August 2014 23:23
To: Masti Ramya Jayaram; l4-hackers at os.inf.tu-dresden.de
Subject: Re: Minimal requirements to run L4linux using only a serial console
Tx path of UART is working but the Rx part not due to missing
interrupts. In the Tx part interrupts are not really required - alt
least not for Hello World. I also don't care about the missing "H" right
now. So the first step would be polling the fiasco UART every 100ms or
so instead of waitung for interrupts.
I don't care abount the missing "H", this could be anything.
Am 29.08.2014 17:45, Masti Ramya Jayaram schrieb:
> Hey Martin,
> No I just realized that ESC does not break into the debugger. But I can clearly see that the process instead of printing "Hello world" prints "ello World" :)
> What could the reason be?
> From: l4-hackers [l4-hackers-bounces at os.inf.tu-dresden.de] on behalf of Martin Schröder [martin.schroeder at openlimit.com]
> Sent: 29 August 2014 17:35
> To: l4-hackers at os.inf.tu-dresden.de
> Subject: Re: Minimal requirements to run L4linux using only a serial console
> Hi Ramya,
> a: No, its not a must. The UART could also be polled (by a timer) to see if something arrived.
> b: At least regarding l4linux there is nothing more to it - afaik.
> But let's go back to the hello word example on the SCC. What happens if you press the <ESC> key? Does it break into the JDB debugger?
> Best regards,
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