Hey Martin,
I cleaned up my build and it worked - the mistake was mine. I had a question
regarding ACPI. The target machine I am using has no BIOS/ACPi support. So,
when I boot linux on it my console input does not work.This is similar to
booting in qemu with the -no-acpi option. Serial
Hey Martin,
Back on the list ;-)
Ok, I can confirm that when I busy loop during fiasco init, I can actually see
the character that I typed. So would I have to change the l4ser driver in Linux
or the main driver in under pkg/l4/bootstrap or under fiasco in vkey.cpp? :)
Thanks,
ramya
Also, given that the thing works with ACPI on, wouldn't it be better to include
ACPI information in the boot instead of changing the driver? Or is this
impossible?
Best,
Ramya
From: Masti Ramya Jayaram
Sent: 29 August 2014 15:55
To: Martin Schröder;
Hi Ramya,
Am 29.08.2014 um 14:29 schrieb Masti Ramya Jayaram:
Hi Martin,
Thanks for checking that. I also see that my build works provided I don't apply a special patch meant for my board (Intel SCC).
The patch essentially only alters the frequency and disables the PIC.
If you disable the
Hi Ramya,
Why did you disable the PIC?
What is your aim with ACPI and why should this lead to a change in the UART
driver?
And what has the serial console to do with ACPI tables?
For me the topics have at the moment very little in common or I am missing
something.
Best regards,
Martin
Hey Martin,
I am trying to run l4linux/fiasco on the Intel SCC which does have a pic-8259.
The Intel SCC does not have a BIOS and does not have any ACPI tables which I
think qemu generates on the fly. It also does not use a Screen or keyboard.
I obtained a patch from Markus Partheymueller
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
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?
Thanks,
Ramya
From: l4-hackers
Also with acpi on, it does enter the debugger in qemu.
Best,
Ramya
From: Masti Ramya Jayaram
Sent: 29 August 2014 17:45
To: Martin Schröder; l4-hackers@os.inf.tu-dresden.de
Subject: RE: Minimal requirements to run L4linux using only a serial console
Hey
Hi Martin,
That was a very useful tip. I simply changed the default value in
kernel/fiasco/src/kern/config.cpp from SERIAL_ESC_IRQ to SERIAL_ESC_NOIRQ which
leads to polling (I am guessing) and voila! It works! I even tried on the
actual SCC and it works! I can break into the debugger as well
Hi All,
I have some further understanding about the code.
If thread A can go back to its home cpu(core 1), this means it is not
running on the core 2.
And when A release its lock, it will switch to its helper.
During the context switch from thread A to its helper on core 2, the
Hi Ramya,
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
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