PW4 Completely shut down a PW4

[invertebrate]

Greetings, thank you all for your hard work! The following questions have partly been answered for older devices but not specifically for the PW4 (unless I'm blind).


What would happen if I issued a poweroff command from the command line on a jailbroken kindle paperwhite 4 (2018)?

Would doing that entail the risk of bricking the device or losing the jailbreak or other miseries that could be considered harmful/undesirable (like losing data, etc.)?

What would have to be done to start it up again afterwards? Is it even possible? How long would it take?

Does it even make sense to attempt doing that?

[ilovejedd]

Originally Posted by invertebrate

What would happen if I issued a poweroff command from the command line on a jailbroken kindle paperwhite 4 (2018)?

Not sure about poweroff but I use a script I found in the Kindle Dev forum.

#!/bin/sh

exec shutdown -P now

Device turns off and you a get the boy under tree image with a "Please wait a moment while your Kindle starts up..." message.

Originally Posted by invertebrate

Would doing that entail the risk of bricking the device or losing the jailbreak or other miseries that could be considered harmful/undesirable (like losing data, etc.)?

Not that I can tell.

Originally Posted by invertebrate

What would have to be done to start it up again afterwards? Is it even possible? How long would it take?

Same as you do when you get a brand new Kindle (press power button for a few seconds) and boot time is just as long.

Originally Posted by invertebrate

Does it even make sense to attempt doing that?

Long term storage, sure. For example, I bought extra Kindles that could be jailbroken for backup purposes that are just sitting in a drawer unused for months on end. Makes sense to turn those off.

Normal usage, just stick to standby.

[odamizu]

This is intriguing. But before I risk messing things up, can you tell me if my understanding is correct?

• Connect Kindle to computer via USB
• Open Terminal window (I'm on Mac)
• Navigate to Kindle root directory ??
• Type: #!/bin/sh and hit return ??
• Type: exec shutdown -P now and hit return ??

This will power down my Kindle completely? Not just sleeping anymore?

And this will work on a non-jailbroken Kindle?

Thank you!

[knc1]

*) Yes
*) Yes
+ do you mean to include "Start USB networking" here?
*) Yes
But you need command line access to do that (kTerm, USB networking, ...)
Since the root of the file system is not exported, only the user area is.
*) Not required when do this interactively on the command line.
*) Yes, sort of.
The only way to completely shut down a Kindle is to remove the battery.
There is always some hardware running, for example, what else would read power button presses when the main processor is sleeping?

[ilovejedd]

Ah, sorry I wasn't clear enough.

Jailbreak is absolutely required (OP is already jailbroken so I didn't feel the need to mention that in my previous reply). I don't connect to USB. Not really up to doing the research on setting up USB networking in Windows 7.

I found a KUAL add-on on this forum that powers down the kindle. That code above was the contents of the shell script that does the shutdown. I just go to KUAL and select Power OFF Kindle (which launches the above script).

[j.p.s]

Originally Posted by odamizu

This is intriguing. But before I risk messing things up, can you tell me if my understanding is correct?

• Connect Kindle to computer via USB
• Open Terminal window (I'm on Mac)
• Navigate to Kindle root directory ??
• Type: #!/bin/sh and hit return ??
• Type: exec shutdown -P now and hit return ??

This will power down my Kindle completely? Not just sleeping anymore?

And this will work on a non-jailbroken Kindle?

Thank you!

If your kindle is not jailbroken and your mac has a shutdown command, the last command would shutdown your mac.

Without jailbreak, the only terminal access to a kindle is over the serial port.

[j.p.s]

Originally Posted by ilovejedd

Ah, sorry I wasn't clear enough.

Jailbreak is absolutely required (OP is already jailbroken so I didn't feel the need to mention that in my previous reply). I don't connect to USB. Not really up to doing the research on setting up USB networking in Windows 7.

I found a KUAL add-on on this forum that powers down the kindle. That code above was the contents of the shell script that does the shutdown. I just go to KUAL and select Power OFF Kindle (which launches the above script).

You could boot KNOPPIX or any other linux live CD and set up USB networking for that. They can be put on USB sticks and set up to have configuration changes persist. The ultimate solution is to come to the light side and run linux.

[odamizu]

Okay, thanks all! This is clearly over my head

[knc1]

Originally Posted by odamizu

Okay, thanks all! This is clearly over my head

The Kindle does have to be jail broken.
Your Mac already has the ssh client installed as part of its standard system.

There are "Mac specific" directions posted here for USB networking and ... (not sure what else).

[ilovejedd]

Originally Posted by j.p.s

You could boot KNOPPIX or any other linux live CD and set up USB networking for that. They can be put on USB sticks and set up to have configuration changes persist. The ultimate solution is to come to the light side and run linux.

I've already got persistent USB sticks with Mint, Kubuntu, Xubuntu and non-persistent Manjaro, Neon and LMDE, plus a multi-boot system with most of the above on a dedicated netbook (i3-3227U, 4GB RAM and 512GB Crucial SSD) which I played with for a couple of months before losing interest. At this point, switching desktop OSes is too much hassle when I'm using an iPad ~80% of the time.

I don't tinker with my Kindle enough to make the effort to setup USB networking. KOReader, LibrarianSync and Screensaver all work so I'm a happy camper.

[atonement]

I had powered off my jailbroken KPW3 at 96%. Powered it on about a day later and battery is shown at 100%!

[NiLuJe]

Not out of the ordinary. The gauge lies to you all the time: it's designed to avoid your battery dying a horrible death, not giving you accurate information.

[atonement]

That figures. I try to not charge it beyond 80% but in case I forget and it charges to 100% it falls to 94% or so rather quickly. I wish there was a way to limit charge to say 80%.

[j.p.s]

Originally Posted by NiLuJe

Not out of the ordinary. The gauge lies to you all the time: it's designed to avoid your battery dying a horrible death, not giving you accurate information.

And the percent charge shown on the display might be a lie about the lie reported by the gauge, which can be greater than 100% because of the values used in the math. The firmware will display 100% for values above 100%.