Kindlet How to make a new Kindlet?

mrfakename · 03-23-2023, 09:27 PM

Hello,
I'm trying to develop a Kindlet for my Kindle 3G. I recently found this thread, but it mentions copying files from the /opt/amazon/ebook/lib/Kindlet-1.1.jar folder. When plugging in my Kindle, I was unable to locate this folder, or any /opt folder.
This post says they removed it, and I was wondering if there is any way to develop a Kindlet today?

Quote:

Originally Posted by xception

It seems that in 5.9.6.1 amazon has removed /opt/amazon/ebook/lib/Kindlet-1.1.jar
is there a workaround, or a copy available ??

Thanks,
mrfakename

dhdurgee · 03-23-2023, 10:14 PM

Quote:

Originally Posted by mrfakename

Hello,
I'm trying to develop a Kindlet for my Kindle 3G. I recently found this thread, but it mentions copying files from the /opt/amazon/ebook/lib/Kindlet-1.1.jar folder. When plugging in my Kindle, I was unable to locate this folder, or any /opt folder.
This post says they removed it, and I was wondering if there is any way to develop a Kindlet today?

Thanks,
mrfakename

No, unless you are willing to backlevel to a firmware with Kindlet support.

You CAN develop a Booklet, which is how the newer version of KUAL works. That interface, however, is obfuscated and only portions of it are known at this point. If you want to try this take a look at KUAL and contact those supporting it at present if you would like to see the code.

Dave

encol · 03-24-2023, 05:34 AM

Quote:

Originally Posted by mrfakename

Hello,
I'm trying to develop a Kindlet for my Kindle 3G. I recently found this thread, but it mentions copying files from the /opt/amazon/ebook/lib/Kindlet-1.1.jar folder. When plugging in my Kindle, I was unable to locate this folder, or any /opt folder.
This post says they removed it, and I was wondering if there is any way to develop a Kindlet today?

Thanks,
mrfakename

Only if your firmware is still compatible

see also these links:
https://www.mobileread.com/forums/sh...d.php?t=219663
http://kimhauser.ch/index.php/articl...hello-world-v2

mrfakename · 03-24-2023, 03:44 PM

Hi,
@encol Thank you so much for the JAR files!
I tried to compile it on my Kindle 3G (here is my code), however I'm getting the following error:

Code:

The title you attempted to open requires a new version of Kindle software. Please update your Kindle to the new software version from the Menu in Settings or the Manage Your Kindle web page. For additional help, please call Kindle Customer Service at 1-866-321-8851 or 206-266-0927

I've never programmed in Java before and I'm new to Kindle development, so I was wondering if this was something with my code or the JAR files? (My Kindle 3G stopped receiving updates long ago).
Thank you so much!

j.p.s · 03-24-2023, 04:23 PM

Quote:

Originally Posted by mrfakename

Hello,
I'm trying to develop a Kindlet for my Kindle 3G. I recently found this thread, but it mentions copying files from the /opt/amazon/ebook/lib/Kindlet-1.1.jar folder. When plugging in my Kindle, I was unable to locate this folder, or any /opt folder.
This post says they removed it, and I was wondering if there is any way to develop a Kindlet today?

Thanks,
mrfakename

How are you trying to access /opt on your kindle?

Also, "Kindle 3G" is ambiguous. What are the first 6 characters of its serial number?

mrfakename · 03-24-2023, 08:48 PM

Hi @j.p.s,
1. This post seems to imply that it has been removed, which may mean that I no longer need /opt, so I'm no longer attempting to access it

Quote:

Originally Posted by xception

It seems that in 5.9.6.1 amazon has removed /opt/amazon/ebook/lib/Kindlet-1.1.jar
is there a workaround, or a copy available ??

2. The first 4 digits are B006A0.

j.p.s · 03-25-2023, 03:15 PM

Quote:

Originally Posted by xception

It seems that in 5.9.6.1 amazon has removed /opt/amazon/ebook/lib/Kindlet-1.1.jar
is there a workaround, or a copy available ??

Quote:

Originally Posted by mrfakename

Hi @j.p.s,
1. This post seems to imply that it has been removed, which may mean that I no longer need /opt, so I'm no longer attempting to access it

That is just 1 specific file.

I have a kindle PW3 running firmware 5.9.6.1, which does not have that file and can not run kindlets, but /opt/amazon/ebook/lib/ does have 560 other files.

I have a reason for asking, and ask again, how specifically did you try to access /opt?

Quote:

2. The first 4 digits are B006A0.

You have a Kindle 3 3G, AKA K3 or K3G. Lots of kindle models have 3G cellular modems, so Kindle 3G covers many kindle models, with many different firmware versions.

Which firmware version are you running?

By the way, the wiki page
https://wiki.mobileread.com/wiki/Kindle_Serial_Numbers
lists the mobileread nicknames for each kindle model.

evilReader · 03-26-2023, 11:36 AM

Quote:

Originally Posted by mrfakename

Hi,
@encol Thank you so much for the JAR files!
I tried to compile it on my Kindle 3G (here is my code), however I'm getting the following error:

Code:

The title you attempted to open requires a new version of Kindle software. Please update your Kindle to the new software version from the Menu in Settings or the Manage Your Kindle web page. For additional help, please call Kindle Customer Service at 1-866-321-8851 or 206-266-0927

I've never programmed in Java before and I'm new to Kindle development, so I was wondering if this was something with my code or the JAR files? (My Kindle 3G stopped receiving updates long ago).
Thank you so much!

I'm guessing you just tried to compile it with whatever java version you are using on your desktop, which won't work. I believe the version you want to target is java 1.4 for K3, though if you have jailbreak access you can try checking the java version by running

Code:

/usr/java/bin/cvm -version

For example on my PW2 at the end of the output:

Code:

java version "1.8.0_211-ea"
Java(TM) SE Embedded Runtime Environment (build 1.8.0_211-ea-b00, profile compact1, headless)
Java HotSpot(TM) Embedded Minimal VM (build 25.211-b00, mixed mode)

It looks like you are using ant to build the project so add these properties to tell it to compile for java 1.4

Code:

<property name="ant.build.javac.source" value="1.4"/>
<property name="ant.build.javac.target" value="1.4"/>

Also in your manifest file, you have the line

Code:

SDK-Specification-Version: 2.1

but this needs to be <= whatever Kindlet-x.x.jar version is on your kindle (So change it to 1.0 or 1.2)

mrfakename · 03-26-2023, 05:51 PM

@evilReader, thank you so much! I performed your recommended fixes and was able to remove the "The title you attempted to open requires a new version of Kindle software." error!
I'm now having another error, however. When I attempt to run my Kindlet, I am getting the following error:

Code:

Main class of the requested title could not be found

I have updated the GitHub code to fix the update issue.
Thank you!

AABBox · 03-27-2023, 09:26 AM

Quote:

Originally Posted by mrfakename

@evilReader, thank you so much! I performed your recommended fixes and was able to remove the "The title you attempted to open requires a new version of Kindle software." error!
I'm now having another error, however. When I attempt to run my Kindlet, I am getting the following error:

Code:

Main class of the requested title could not be found

I have updated the GitHub code to fix the update issue.
Thank you!

This error is because the kindle can not find the main class.

In your build.xml, make sure you define the following:

Code:

<attribute name="Main-Class" value="test.main" />

I plan to open up a template repo with a working Kindlet app at some point, as I've spent the past year or so making a Kindlet at work.

mrfakename · 03-27-2023, 03:46 PM

Hi,
Thank you @AABBox! I tried your fixes, however I'm still getting the class not found error. I looked more carefully at my console and realized it may have something to do with my Java installation. I'm very new to Java so I might be completely wrong, but here's my console output:

Code:

added manifest
adding: src/test/(in = 0) (out= 0)(stored 0%)
adding: src/test/main.java(in = 624) (out= 254)(deflated 59%)
Buildfile: <DIRECTORY>build.xml

compile:
    [javac] <DIRECTORY>build.xml:15: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
    [javac] Compiling 1 source file to <DIRECTORY>/bin
    [javac] warning: [options] bootstrap class path not set in conjunction with -source 1.4
    [javac] error: Source option 1.4 is no longer supported. Use 7 or later.
    [javac] error: Target option 1.4 is no longer supported. Use 7 or later.

BUILD FAILED
<DIRECTORY>/build.xml:15: Compile failed; see the compiler error output for details.

Total time: 0 seconds
jar signed.

Warning:
The signer's certificate is self-signed.
jar signed.

Warning:
The signer's certificate is self-signed.
jar signed.

Warning:
The signer's certificate is self-signed.

I don't know if this is the issue, because when I ran "jar tf kindlet.azw2," it seems to have compiled properly:

Code:

$ jar tf kindlet.azw2
META-INF/MANIFEST.MF
META-INF/DNKINDLE.SF
META-INF/DNKINDLE.RSA
META-INF/DIKINDLE.SF
META-INF/DIKINDLE.RSA
META-INF/DKKINDLE.SF
META-INF/DKKINDLE.RSA
META-INF/
src/test/
src/test/main.java
$ jar tf kindlet.jar
META-INF/
META-INF/MANIFEST.MF
src/test/
src/test/main.java

Thank you!

evilReader · 03-27-2023, 05:49 PM

It looks like you have the source file for main.java in the jar, you need to put the compiled .class files into the jar for it to run.

evilReader · 03-27-2023, 05:53 PM

Quote:

Originally Posted by mrfakename

Hi,
Thank you @AABBox! I tried your fixes, however I'm still getting the class not found error. I looked more carefully at my console and realized it may have something to do with my Java installation. I'm very new to Java so I might be completely wrong, but here's my console output:

Code:

added manifest
adding: src/test/(in = 0) (out= 0)(stored 0%)
adding: src/test/main.java(in = 624) (out= 254)(deflated 59%)
Buildfile: <DIRECTORY>build.xml

compile:
    [javac] <DIRECTORY>build.xml:15: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
    [javac] Compiling 1 source file to <DIRECTORY>/bin
    [javac] warning: [options] bootstrap class path not set in conjunction with -source 1.4
    [javac] error: Source option 1.4 is no longer supported. Use 7 or later.
    [javac] error: Target option 1.4 is no longer supported. Use 7 or later.

BUILD FAILED
<DIRECTORY>/build.xml:15: Compile failed; see the compiler error output for details.

Total time: 0 seconds
jar signed.

Warning:
The signer's certificate is self-signed.
jar signed.

Warning:
The signer's certificate is self-signed.
jar signed.

Warning:
The signer's certificate is self-signed.

I don't know if this is the issue, because when I ran "jar tf kindlet.azw2," it seems to have compiled properly:

Code:

$ jar tf kindlet.azw2
META-INF/MANIFEST.MF
META-INF/DNKINDLE.SF
META-INF/DNKINDLE.RSA
META-INF/DIKINDLE.SF
META-INF/DIKINDLE.RSA
META-INF/DKKINDLE.SF
META-INF/DKKINDLE.RSA
META-INF/
src/test/
src/test/main.java
$ jar tf kindlet.jar
META-INF/
META-INF/MANIFEST.MF
src/test/
src/test/main.java

Thank you!

Looking at the compiler output,

Code:

    [javac] error: Source option 1.4 is no longer supported. Use 7 or later.
    [javac] error: Target option 1.4 is no longer supported. Use 7 or later.

It never properly compiled the .java into .class files, looks like the JDK you have installed is too new. Try using java 8, that's what worked for me.

mrfakename · 03-28-2023, 05:38 PM

@evilReader thank you so much! I switched to Java 8 and it worked perfectly! I'm now running into another problem with the keystore but I opened a different thread for that.
Thank you again!

03-24-2023, 03:44 PM	#4
mrfakename Developer Posts: 18 Karma: 15056 Join Date: Mar 2023 Device: Kindle 3G (Customized - Fonts + Screen Saver)	Hi, @encol Thank you so much for the JAR files! I tried to compile it on my Kindle 3G (here is my code), however I'm getting the following error: Code: The title you attempted to open requires a new version of Kindle software. Please update your Kindle to the new software version from the Menu in Settings or the Manage Your Kindle web page. For additional help, please call Kindle Customer Service at 1-866-321-8851 or 206-266-0927 I've never programmed in Java before and I'm new to Kindle development, so I was wondering if this was something with my code or the JAR files? (My Kindle 3G stopped receiving updates long ago). Thank you so much!

03-26-2023, 05:51 PM	#9
mrfakename Developer Posts: 18 Karma: 15056 Join Date: Mar 2023 Device: Kindle 3G (Customized - Fonts + Screen Saver)	@evilReader, thank you so much! I performed your recommended fixes and was able to remove the "The title you attempted to open requires a new version of Kindle software." error! I'm now having another error, however. When I attempt to run my Kindlet, I am getting the following error: Code: Main class of the requested title could not be found I have updated the GitHub code to fix the update issue. Thank you!

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03-27-2023, 05:49 PM	#12
evilReader Junior Member Posts: 8 Karma: 84 Join Date: Mar 2023 Device: Kindle Paperwhite 2	It looks like you have the source file for main.java in the jar, you need to put the compiled .class files into the jar for it to run.

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mrfakename Developer Posts: 18 Karma: 15056 Join Date: Mar 2023 Device: Kindle 3G (Customized - Fonts + Screen Saver)	@evilReader thank you so much! I switched to Java 8 and it worked perfectly! I'm now running into another problem with the keystore but I opened a different thread for that. Thank you again!