Minimal requirements to run L4linux using only a serial console

Martin Schröder martin.schroeder at openlimit.com
Fri Aug 29 16:29:48 CEST 2014


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


Am 29.08.2014 um 15:58 schrieb Masti Ramya Jayaram:
> 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; l4-hackers at os.inf.tu-dresden.de
> Subject: RE: Minimal requirements to run L4linux using only a serial console
>
> 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
> ________________________________________
> From: Masti  Ramya Jayaram
> Sent: 29 August 2014 12:15
> To: Martin Schröder; l4-hackers at os.inf.tu-dresden.de
> Subject: RE: Minimal requirements to run L4linux using only a serial console
>
> 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 console output works (I can see the prompt of L4Linux) but input does not.
>
> Is there something special to do when booting with a serial console but no ACPI tables?
>
> Thanks,
> ramya
> ________________________________________
> From: Martin Schröder [martin.schroeder at openlimit.com]
> Sent: 27 August 2014 18:32
> To: Masti  Ramya Jayaram; l4-hackers at os.inf.tu-dresden.de
> Subject: Re: Minimal requirements to run L4linux using only a serial console
>
> Hi Masti,
>
> you have  all of them already! I did not alter any other file beside the files you already sent. I inserted them into a fresh
> snapshot (http://l4re.org/download/snapshots-oc/l4re-snapshot-2014053111.tar.xz) and started building. Since "drops-rd.rd" was not
> found in the snapshot, I just renamed "ramdisk-x86.rd" to "drops-rd.rd". Nothing more.
>
> Martin
>
>
>
> Am 27.08.2014 um 18:02 schrieb Masti Ramya Jayaram:
>> Hey Martin,
>>
>> thanks for the quick response. Could you send me your configs (l4linux, fiasco, l4re) so that I can try it with that?
>>
>> Thanks,
>> Ramya
>> ________________________________________
>> From: l4-hackers [l4-hackers-bounces at os.inf.tu-dresden.de] on behalf of Martin Schröder [martin.schroeder at openlimit.com]
>> Sent: 27 August 2014 16:28
>> To: l4-hackers at os.inf.tu-dresden.de
>> Subject: Re: Minimal requirements to run L4linux using only a serial console
>>
>> Hi Masti,
>>
>> I just applied your config, replaced "drops-rd.rd" by "ramdisk-x86.rd" and everything (command prompt, debugger) runs fine as
>> expected in Qemu. Maybe you ran into a similar problem as described in this thread:
>>
>> http://os.inf.tu-dresden.de/pipermail/l4-hackers/2012/thread.html#5165
>>
>>
>> Best regards,
>>       Martin
>>
>>
>> Am 27.08.2014 um 15:18 schrieb Masti Ramya Jayaram:
>>> Sorry, a couple of typos in the l4linux.cfg
>>> --vim:set ft=lua:
>>>
>>>
>>> L4.default_loader:start({ caps = {
>>>          log = L4.Env.log:m("rws"),
>>>        },
>>>        l4re_dbg = L4.Dbg.Warn,
>>>        log = { "l4linux", "yellow" },
>>>      }, "rom/vmlinuz mem=64M console=ttyLv0 l4x_rd=rom/drops-rd.rd root=1:0 ramdisk_size=4000 l4ser.vkey_enable=1");
>>>
>>> Thanks in advance,
>>> ramya
>>>
>>> ________________________________________
>>> From: l4-hackers [l4-hackers-bounces at os.inf.tu-dresden.de] on behalf of Masti  Ramya Jayaram [rmasti at inf.ethz.ch]
>>> Sent: 27 August 2014 14:07
>>> To: l4-hackers at os.inf.tu-dresden.de
>>> Subject: Minimal requirements to run L4linux using only a serial console
>>>
>>> Dear all,
>>>
>>> I am trying to run L4linux on fiasco/l4re but with the keyboard and VGA disabled. I can get all the way to the command prompt (of the shell) in the initramfs but then, on pressing a key, I get a page fault and I cannot debug the system anymore using the serial_esc. I suspect it is my configuration which I have provided below. I was wondering what the minimal packages are to achieve this.
>>>
>>> modules.list:
>>> entry l4linux
>>> kernel fiasco -serial_esc -freq=533000
>>> roottask moe rom/l4linux.cfg
>>> module l4re
>>> module ned
>>> module l4linux.cfg
>>> module io
>>> module vmlinuz
>>> module drops-rd.rd
>>>
>>> I have disabled the framebuffer and input server in the L4linux stub drivers configuration and enabled the serial console.
>>>
>>> l4linux.cfg:
>>>
>>> --vim:set ft=lua:
>>>
>>> L4.default_loader:start({ caps = {
>>>          log = L4.Env.log:m("rws"),
>>>        },
>>>        l4re_dbg = L4.Dbg.Warn,
>>>        log = { "l4linux", "yellow" },
>>>      }, "rom/io -vvvv rom/vmlinuz mem=64M console=ttyLv0 l4x_rd=rom/drops-rd.rd root=1:0 ramdisk$
>>>
>>>
>>> I also specify a custom frequency for my board to fiasco.oc, do I have to make similar modifications to l4linux (e.g., Timer frequency)?
>>>
>>> Thanks,
>>> Ramya




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