[Voyage-linux] Several comments on Voyage 0.75

[Kim-man 'Punky' TSE]

Hi Edwin,

Honestly, I like patches more than comments...

1. PXE boot is /dev/sda:  Can you remove "all_generic_ide" in /tftpboot/pxelinux.cfg/default and see if it could change 
back to /dev/hda?

2. Timing.  I have no idea about clocksource as this really don't matter me.  But seem the kernel can safe adjust to use 
an accurate clock source.

3. Displaylink.  I can add udlfb kernel module to next kernel release.  For xorg driver, please contact or submit bug to 
Debian.

4. CPU optimization.  Voyage kernel should be compiled in CONFIG_M486 for generic purpose.  I am not sure what you want 
to point out.

On 8/16/2011 11:36 PM, Edwin van Drunen wrote:
> Hello,
>
> I have been using Voyage since version 0.6.0 for many industrial systems and have been very satisfied with it. Some 
> custom fixes were applied to previous versions of voyage that don't work anymore in 0.7.5 and I found several issues 
> with version 0.7.5 that maybe can be easily fixed in the base image:
>
> ### Problem: CF card is /dev/sda instead of /dev/hda
> When using the voyage 0.7.5 live CD to PXE boot an Alix 2D13 board, the compact flash card is recognised as /dev/sda.
> The automated installer assumes the CF card to be /dev/hda and therefore the installer won't work. It has to be 
> installed manually using voyage.update and selecting /dev/sda as the target
>
> After the installation is finished and the board has rebooted, the CF card is recognised as /dev/hda.
>
>
> ### Timing
> I had a lot of timing issues with Voyage 0.6.5 and 0.7.0.
> The kernel (2.6.32-voyage) would complain that clocksource "tsc" was unstable and use "jiffies" instead. The clock 
> would drift with several minutes every hour and NTP was unable to keep the clock in sync.
> Since Voyage 0.65 I added "clocksource=tsc" bootparameter to grub's menu.lst and combine it with NTP to keep the clock 
> in sync and this worked well.
>
> Besides that I added the following things to properly access the hardware clock during boot on alix boards:
> add "rtc" to '/etc/modules'
> add "HCTOSYS_DEVICE=rtc" to '/etc/default/rcS'
>
> The new kernel (2.6.38-voyage) now uses "pit" as clocksource on the Alix 2D13. After 10 hours the clock was 5 seconds 
> behind. This is something that NTP can manage. Are there any other significant differences or advantages to using pit 
> instead of tsc?
>
>
> ### Displaylink USB monitor drivers
> The "udlfb" driver module for Displaylink devices is included in kernel 2.6.38. It would be nice if the module could 
> be part of the default voyage kernel:
> Device Drivers -> Graphics support -> Support for frame buffer devices -> Displaylink USB framebuffer support -> M
>
> For use if the monitor in Xorg the video driver "xserver-video-xorg-displaylink" is also needed, but this is not part 
> of the Debian distribution. Ubuntu does have packages and source available.
> Currently I build this module on the Voyage SDK myself, but also this would be a good addition to the Voyage distribution.
>
>
> ### Kernel CPU optimization
> The default kernel is optimised for 486 and higher CPU's and using 586 on the Geode LX CPU's would make performance worse.
> Now there is also a Geode LX option in the kernel. Does this increase performance or enable features otherwise not used?
>
>
>
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-- 
Regards,
Kim-man "Punky" Tse

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