MobileRead Forums - View Single Post - Router + USB keyboard <-> Kindle input

knc1 · 04-02-2015, 12:03 AM

First consideration, and a show-stopper if you don't make allowances for it:

Linux (any *nix) **MUST** have an "operator console" device.
It will not boot without one, talk about an early failure, it will not even complete pre-boot initialization.

Note: The system only needs something to send to, it doesn't matter if there is anything "listening" on the other end.
(An unmodified Kindle does not have anything listening on the other end - other than the empty solder pads.

)

- - - - -

So to free up the hardwired serial port (that we know of, there are probably at least four others on the SoC) -
Move the "operator console" to something else -
Say, a network console:
https://mindplusplus.wordpress.com/2...sole-on-linux/

If Amazon didn't supply that kernel module (they probably don't) -
You can grab the Amazon, kernel source release, and build one "after the fact" as it where.
It will work just as if Amazon had built it for you.

See:
https://mindplusplus.wordpress.com/2...sole-on-linux/
For a spoiler on this part of your project.

Note: Yes, you could put the "operator console" on one of the ports (if u-boot initializes them) that don't have any external connections.
Above I just assumed you want to log the kernel message output so you have a hint as to why the Kindle bricked when it got to the next part of your modifications.

- - - - -

Next, you want to setup another console device, using the (now freed) known serial port.

A spoiler on this part of the project:
https://www.howtoforge.com/setting_up_a_serial_console

**READ THE COMMENTS**
The devices using series 5.x firmware use upstart for user space initialization.

You can ignore the specifics about GRUB and/or LILO - embedded devices **usually** don't use them (Kindles don't - they use u-boot).

But it is unlikely that you need to export the u-boot console.

- - - -

The above is only a **teaser** - not a worked out solution.
It is hard to provide a worked out solution when the final use of this serial port is unknown.

Ah, but the above should have enough Linux-Specific keywords and phrases to get started with a web-search tool for other parts of the solution.
That is, to whatever it is you want to "solve"

.

- - - - -

For GUI input, you will have to tweak the input event device(s) that the standard Kindle GUI listens/talks to so that your new serial input is used instead.

Then use one (or two, send and receive) pairs of Kindle-local and Kindle-remote copies of netcat (or some such tool) to forward your new serial input device somewhere else that is network connected.

Note: you have not opened up your Kindle, only diddled with its system software setup.
Hint: practice on something, such as a Kindle Touch, that can be de-bricked with Kubrick when you screw it up.

04-02-2015, 12:03 AM	#5
knc1 Going Viral Posts: 17,212 Karma: 18210809 Join Date: Feb 2012 Location: Central Texas Device: No K1, PW2, KV, KOA	First consideration, and a show-stopper if you don't make allowances for it: Linux (any nix) MUST* have an "operator console" device. It will not boot without one, talk about an early failure, it will not even complete pre-boot initialization. Note: The system only needs something to send to, it doesn't matter if there is anything "listening" on the other end. (An unmodified Kindle does not have anything listening on the other end - other than the empty solder pads. ) - - - - - So to free up the hardwired serial port (that we know of, there are probably at least four others on the SoC) - Move the "operator console" to something else - Say, a network console: https://mindplusplus.wordpress.com/2...sole-on-linux/ If Amazon didn't supply that kernel module (they probably don't) - You can grab the Amazon, kernel source release, and build one "after the fact" as it where. It will work just as if Amazon had built it for you. See: https://mindplusplus.wordpress.com/2...sole-on-linux/ For a spoiler on this part of your project. Note: Yes, you could put the "operator console" on one of the ports (if u-boot initializes them) that don't have any external connections. Above I just assumed you want to log the kernel message output so you have a hint as to why the Kindle bricked when it got to the next part of your modifications. - - - - - Next, you want to setup another console device, using the (now freed) known serial port. A spoiler on this part of the project: https://www.howtoforge.com/setting_up_a_serial_console READ THE COMMENTS The devices using series 5.x firmware use upstart for user space initialization. You can ignore the specifics about GRUB and/or LILO - embedded devices usually don't use them (Kindles don't - they use u-boot). But it is unlikely that you need to export the u-boot console. - - - - The above is only a teaser - not a worked out solution. It is hard to provide a worked out solution when the final use of this serial port is unknown. Ah, but the above should have enough Linux-Specific keywords and phrases to get started with a web-search tool for other parts of the solution. That is, to whatever it is you want to "solve" . - - - - - For GUI input, you will have to tweak the input event device(s) that the standard Kindle GUI listens/talks to so that your new serial input is used instead. Then use one (or two, send and receive) pairs of Kindle-local and Kindle-remote copies of netcat (or some such tool) to forward your new serial input device somewhere else that is network connected. Note: you have not opened up your Kindle, only diddled with its system software setup. Hint: practice on something, such as a Kindle Touch, that can be de-bricked with Kubrick when you screw it up. Last edited by knc1; 04-02-2015 at 12:25 AM.