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 as input to l4linux.
Thanks a lot for your help for your help. Best, Ramya ________________________________________ From: Masti Ramya Jayaram Sent: 29 August 2014 17:48 To: Martin Schröder; l4-hackers@os.inf.tu-dresden.de Subject: RE: Minimal requirements to run L4linux using only a serial console 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 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 [l4-hackers-boun...@os.inf.tu-dresden.de] on behalf of Martin Schröder [martin.schroe...@openlimit.com] Sent: 29 August 2014 17:35 To: l4-hackers@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, Martin Am 29.08.2014 um 16:56 schrieb Masti Ramya Jayaram: > 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 which they used to boot fiasco > on the SCC. With it I am able to run hello world both in qemu with no-acpi as > well as on the SCC successfully. > > The patch to the best of my knowledge does the following: > > a. Makes the cmdline also parse an argument so that the frequency is an input > (533Mhz) > b. Uses the apic timer for scheduling. > c. Disables the pic-8259 because it does not exist. Instead the core in the > SCC has two interrupt lines and this patch initializes these lines as > interrupts to the core. > d. Disables keyboard and screen and enables a serial line for communication > instead > e. Disables super pages because the SCC does not support it. > > So, when I try the patched fiasco/L4linux on qemu, it works when I do not > disable acpi. But since the SCC does not have any ACPI/IO-APIC, when I try to > run the same thing on qemu with ACPI off, l4linux boots but is not responsive > to input. > > In short: > > when I run with I (below) , my l4linux responds to input and with II (below) > not. > > qemu-system-i386 -m 256 -serial stdio -kernel bootstrap_l4linux.elf -append > "-arg=fiasco,,-serial_esc -freq=533000" > > qemu-system-i386 -no-acpi -m 256 -serial stdio -kernel bootstrap_l4linux.elf > -append "-arg=fiasco,,-serial_esc -freq=533000" > > Now the question is: > > a. Is the IO-APIC a must for the serial line? > b. Are ACPI tables just a matter of writing data at the right memory > locations (e..g, qemu lets you give the acpi-table as input I noticed)? Or > is there more to it? > > Thanks for your patience, > ramya > > > ________________________________________ > From: l4-hackers [l4-hackers-boun...@os.inf.tu-dresden.de] on behalf of > Martin Schröder [martin.schroe...@openlimit.com] > Sent: 29 August 2014 16:29 > To: l4-hackers@os.inf.tu-dresden.de > Subject: Re: Minimal requirements to run L4linux using only a serial console > > 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@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@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.schroe...@openlimit.com] >> Sent: 27 August 2014 18:32 >> To: Masti Ramya Jayaram; l4-hackers@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-boun...@os.inf.tu-dresden.de] on behalf of >>> Martin Schröder [martin.schroe...@openlimit.com] >>> Sent: 27 August 2014 16:28 >>> To: l4-hackers@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-boun...@os.inf.tu-dresden.de] on behalf of >>>> Masti Ramya Jayaram [rma...@inf.ethz.ch] >>>> Sent: 27 August 2014 14:07 >>>> To: l4-hackers@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 _______________________________________________ l4-hackers mailing list l4-hackers@os.inf.tu-dresden.de http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers _______________________________________________ l4-hackers mailing list l4-hackers@os.inf.tu-dresden.de http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers