Hi Stefan
I run into the same problem with you and trying to look for an HR
timer solution for my ts7800 board.
However, I tried to port 2.6.28 kernel to my board, I encountered some
trouble:
Compiling is fine, but when I tried to boot the board with new kernel
Image, the following error message pops up:
VFS: Cannot open root device "ram0" or unknown-block( 2,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block( 2,0)
Did you run into the same problem when applying 2.6.29 kernel?
Thanks
Henry
--- In Stefan Agner <> wrote:
>
> Hello,
>
> I try to reach some Real Time needs with the TS-7800 board.
Therefore a patched the 2.6.21-ts kernel with Ingo's PREEMPT_RT-Patch
which worked fine so far. The kernel boots completely. I tried to
compile the "RT-Hello world" from
http://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO. I inserted code
so that a Sqarewave should be visible on some GPIO pins (see
Attachment, compile with gcc -lrt rthello.c). This works so far, my
oscilloscope shows a sqarewave, but not with 50us distance, but with
10ms distance. I already read about here in the mailing list. As far
as I understood the discussions, it seems to be a problem of lacking
HRTimers:
>
> # cat /proc/timer_list
> Timer List Version: v0.3
> HRTIMER_MAX_CLOCK_BASES: 2
> now at 102967692000 nsecs
>
> cpu: 0
> clock 0:
> .index: 0
> .resolution: 10000000 nsecs
> .get_time: ktime_get_real
> active timers:
> clock 1:
> .index: 1
> .resolution: 10000000 nsecs
> .get_time: ktime_get
> active timers:
>
> I then compiled Alexander Clouter's tree (which is a 2.6.29-rc5
kernel) with High Resolution Timers but without PREEMPT_RT Patch
(wasnt avilable for rc5 atm). But anyway, here they are, real HRTimers:
>
> # cat /proc/timer_list
> Timer List Version: v0.4
> HRTIMER_MAX_CLOCK_BASES: 2
> now at 606613986235 nsecs
>
> cpu: 0
> clock 0:
> .base: c048a440
> .index: 0
> .resolution: 1 nsecs
> .get_time: ktime_get_real
> .offset: 1235464200238099709 nsecs
> active timers:
> clock 1:
> .base: c048a470
> .index: 1
> .resolution: 1 nsecs
> .get_time: ktime_get
> .offset: 0 nsecs
>
> My squarewave example worked, this time with 50us distance, but with
some misses (due to lack of PREEMPT_RT).
>
> Now, my question, does anybody brought the HRTimers on 2.6.21-ts
kernel to work? Or the other way around, does anyone ported the
NAND/SD drivers to 2.6.29? Alexander Clouter told me that MTD works
without DMA (which is not optimal for my needs) and SD doesnt work at
all atm. All the other devices should work (network, usb does for sure)...
>
> Thanks
> bye
> Stefan
>
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ts-7000/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|