Random Screensaver Image

[Liriel]

mmh with 3.18.0 on my glo work it not with the new offset data

[frostschutz]

It's different for every device and language... you'll have to use the debug mode to get correct values for the Glo and whatever language you're using, unless someone else does it and shares their settings.

I will try to make the setup easier in the future but right now it's the way it is

[Liriel]

mmh with 17.3 there was no need to edit the setting

[frostschutz]

Yup, but the logread method no longer works in 3.18.0, Kobo removed the log messages...

[Bandi-T]

My Aura H2O 3.18.0 in English needed:

offset=150
standby=f400e0d8bdc587d96e9d14fcd584144c

As a thank you, attached are a few random sleep screen PNG images - the last one is, of what else, but nickel.

[Bandi-T]

Hmm, I am experiencing race conditions: sometimes the custom image gets displayed for a moment, but then gets overwritten again by the kobo sleep screen image.

I'm wondering, wouldn't it be better to strace the hell out of nickel to see the what it does when going to sleep, and then do an LD_PRELOAD hook into whatever it is actually doing? Like actually invoking the power state transition (be that done through open()ing and write()ing to a device file, or a syscall)?

[frostschutz]

@Bandi-T: is that using scanline mode? and have you disabled Kobo's cover/progress options, it probably works best with the plain "standby" screen?

Possible problems with scanline mode are... using the wrong signature, or using the wrong delay values. If you're not on 3.18.0 firmware and still using logread mode, your best bet is the delay option as well, see if other values work better.

There is another screensaver mod that does the LD_PRELOAD. I'm trying to avoid this solution though, as it would raise the conflict potential with other mods [that modify rcS and use their own preloads already such as the night mode].

Basically in order to control the preload you also have to control the nickel startup but I don't [it could be started by rcS, it could be started by KSM, it could be with or without nightmode, etc. etc.].

I rather prefer my mod to be an external/independent entity, although the scanline solution is already breaking that rule a little by hooking into 'dd'...

[tshering]

Originally Posted by Bandi-T

and then do an LD_PRELOAD hook into whatever it is actually doing?

You might be interested in this approach. You can find the most recent version here.

[NiLuJe]

There's always /etc/ld.so.preload if you don't want to mess with init scripts (provided Kobo's ld.so isn't hobbled to prevent that).

[frostschutz]

But that's not limited to nickel... is it?

I'm not sure if I want to have custom libraries preloaded for everything.

Besides, there already is a screensaver mod that does just that, so I don't have to do it.

[NiLuJe]

@frostschutz: True .

(FWIW, Amazon does it on the Kindle to enforce locales).

[Bandi-T]

Originally Posted by frostschutz

@Bandi-T: is that using scanline mode?

Yes to all: Aura H2O, 3.18.0, English, scanline mode, kobo sleep screen is plain "Sleeping" displayed on white background.

Originally Posted by frostschutz

wrong delay values.

I suspect this is my issue, yes. Must confess haven't looked at these options yet - I assumed it was only neeeded for the scanline detection, which does seem to work each time. I'll take a proper look at the docs.

Originally Posted by frostschutz

There is another screensaver mod that does the LD_PRELOAD.

Ahh, lovely, I must take a look; apologies, I haven't stumbled upon it yet, did not think there would be several, so once I found yours I stopped looking.

Originally Posted by frostschutz

Basically in order to control the preload you also have to control the nickel startup but I don't [it could be started by rcS, it could be started by KSM, it could be with or without nightmode, etc. etc.].

For the first issue, replacing nickel with a shell script should do the trick. Granted, chaining multiple mods would need a framework to be established.

Originally Posted by frostschutz

I rather prefer my mod to be an external/independent entity, although the scanline solution is already breaking that rule a little by hooking into 'dd'...

Yes, I can see your design goal now, thanks for highlighting and apologies for being unaware of my surroundings. And yes, hacking into dd is what led me down this slippery thinking slope of replacing nickel with a shell script doing preload.

[frostschutz]

The nickel binary is 5M, so if you replace it with a shell script and then make a firmware update (bye your shellscript), you've wasted 5M of the internal memory. Now, there is ~100M free internally which seems like a lot, but... and then you still have the issue that all mods have to cooperate on this somehow.

It might still come to that, depending on which ways Kobo decides to break this mod in the future.

Yes to all: Aura H2O, 3.18.0, English, scanline mode, kobo sleep screen is plain "Sleeping" displayed on white background.

If the screensaver is displayed _before_ the Kobo ever displayed "Sleeping" then you have the wrong signature. With scanline mode there should be no race as it's supposed to react only after Kobo already displayed "Sleeping". [And as far as I'm aware Kobo does not display "Sleeping" twice]. If the screensaver is not displayed at all, then it could be either wrong signature or wrong delay.

I'm still hoping to find a way to improve the scanline method, right now it's impossible to tell what the signature stands for, so it's easy to pick the wrong one.

As for delay, smaller delays work better for scanline mode, so try delay=0.1 0.1 0.1 0.1 0.1

[Liriel]

ok i have found the setting for my Kobo Glo with 3.18.0 in German with scanline setting

offset=150
standby=a9895b287a8a132de16bbd63e853d8f4
poweroff=0bfbd0ae1eb3aec960d7d9728914ee9d

it wont work with setting logread.

@frostschutz
da ist noch ein kleines problem.
ich versuchs dir auf deutsch zu erklären da du ja von hier bist.
wenn man aus dem schlaf modus raus geht ist oft kurz das menü zu sehen und dann kommt wieder das bild vom screensaver zum vorschein.
das geht dann nur weg in dem bereich was geändert wird.
da ist noch ein kleines problem das ab und an auftrifft

[Symptym]

Just tried this on my Aura HD running 3.18.0 in English.

Still getting the delay timings right (it's still leaving 'power off' on occasion when I'm testing it) but the offset and patterns seem to work just fine.

offset=145
standby=f400e0d8bdc587d96e9d14fcd584144c
poweroff=0721f0fe4c1e6e1b1e4137531f2fea80

I'm considering running the offsets and patterns for other languages if I can get the delay timings so if anybody has them I'd be pretty grateful.