RED Brick fast image: Speed vs Features

Hi,

When we started with the fast image of the RED Brick it had a really fast boot time (~12-15 seconds boot time). But then we added lots of features and we were not able to optimize the boot time before the release again.

Currently the boot process of the fast image looks as follows:

http://i.imgur.com/sIxhuwY.png

The biggest offenders are:

* apache (webserver): Uses about 2.4 seconds CPU and 7 seconds IO.

* fbi (frame buffer imageviewer, shows the TF logo at during boot): Uses about 1 second IO.

* python+wicd (ethernet/wifi management): Uses about 1.6 seconds CPU.

I currently think that we should remove fbi from the fast image (it is not supposed to support HDMI anyway) and we should disable Apache by default and add a button to Brick Viewer that allows to enable/disable Apache.

With these changes we are probably down to ~20 seconds boot time. What do you guys think? Would you rather have all features enabled in the fast image too? The fast image will always have the benefit of more RAM (because of the disabled GPU).

Hello borg,

just a remark: It is a big time difference to boot to HDMI-Graficmode or HDMI-Textmode?

I would prefer a Textmodescreen also in Fast-Image for debugging/console issues.

Is there the possibility to create only one image and switch between Fast- and Featuremode via Brickviewer followed by a reboot?

Thanks.

Der Loetkolben

Hello borg,

 

just a remark: It is a big time difference to boot to HDMI-Graficmode or HDMI-Textmode?

 

I would prefer a Textmodescreen also in Fast-Image for debugging/console issues.

Yes, there will automatically be a framebuffer text mode if we remove the splash screen.

Is there the possibility to create only one image and switch between Fast- and Featuremode via Brickviewer followed by a reboot?

That is not easily possible. In the fast image, the GPU is disabled directly in the kernel configuration, which means that a different Linux kernel is used. This is by far the most important feature of the fast image, since the GPU shares RAM with the CPU and hence the fast image has more RAM available.

I do like the idea, optimally we would just have some checkboxes in brickv, such as

* [ ] Use GPU

* [ ] Start X

* [ ] Start Apache (webserver)

* [ ] Use splashscreen

* [ ] ...

Is there the possibility to create only one image and switch between Fast- and Featuremode via Brickviewer followed by a reboot?

That is not easily possible.

I didn't looked at RED git repo, but if You use DeviceTree in your RED kernel, then it should be quite easy to switch to GPU/nonGPU mode trought fw_setenv-->uboot-->DT-->Kernel

I do like the idea, optimally we would just have some checkboxes in brickv, such as

 

* [ ] Use GPU

* [ ] Start X

* [ ] Start Apache (webserver)

* [ ] Use splashscreen

* [ ] ...

 

nice!