[coreboot] x60 : trying to boot to a debian in less than 2 seconds

[Paul Menzel]

Dear Charles,


Am Sonntag, den 24.08.2014, 23:25 -0400 schrieb Charles Devereaux:

> I'm still trying to improve boot time.

nice. Thank you for keeping us in the loop.

> After some further optimizations (previous results : 2.2s for the kernel,
> 0.6s for the daemons),

1. So what are your coreboot numbers? (Also what `.config` and what
payload (with `.config`) do you use?)

2. What hardware do you use? Especially what SSD?

3. Do you use the default Linux kernel shipped with Debian?

4. Which Debian release do you use?

5. Which init system do you use?

> I believe it should be possible to get a command line in less than 2
> seconds, since most of the time is spend re-initializing the video
> chip (almost a full second) while there are some features to prevent
> just that.

That sounds indeed possible. How do you measure the timings?

> It seems that coreboot is spending some time initializing the video chip
> for grub, then linux spends some time again - even when grub option "set
> gfxpayload=keep" is set (which should prevent that) and when coreboot is
> compiled with CONFIG_FRAMEBUFFER_KEEP_VESA_MODE
> 
> in kernel 3.10.45 :
> [    0.291014] [drm] GMBUS [i915 gmbus panel] timed out, falling back to bit banging on pin 3
> [    0.321926] [drm] initialized overlay support
> [    0.384013] [drm] GMBUS [i915 gmbus vga] timed out, falling back to bit banging on pin 2
> [    0.570068] fbcon: inteldrmfb (fb0) is primary device
> [    1.230010] Console: switching to colour frame buffer device 128x48
> [    1.258981] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
> [    1.258984] i915 0000:00:02.0: registered panic notifier
> [    1.258992] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
> 
> I'm currently trying a recent kernel since some i915 patches have been
> backported (cf http://blog.ffwll.ch/2014/04/neat-drmi915-stuff-for-315.html),
> introducing the i915.fastboot option to do just that, but it does not help.
> 
> I must be doing something terribly wrong, but I just don't realize what
> exactly.
> 
> Has anyone succeeded in keeping the vesa mode?

Sorry, I have not played with this. But I think the way to go is to
contact the Linux Intel graphics folks. Best is to submit a bug report.
Let’s hope to get that fixed for Debian Jessie, which is going to be
frozen in November [1].

Another approach would be to do it like the Chromium OS folks do it on
the Google Chromebooks. In normal mode they do not initalize the graphic
device (just place the Video BIOS/VGA Option ROM for VBT information),
so you cannot see GRUB, and let just Linux initialize the graphics. Then
they have a developer mode and only in this mode coreboot does graphics
initialization.

As these are smart people and they probably did a lot of testing, that
might be the only viable solution if you want to have quick boot times.
Though I have no idea why they did not go the `gfxpayload=keep` route.


Thanks,

Paul


[1] https://release.debian.org/jessie/freeze_policy.html
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