kindle (dxg) kernel/rootfs postmarketos port possibilities?

[unrznbl]

I have found this howto https://yifan.lu/2010/07/26/compilin...amazon-kindle/

and am wondering if anyone else has played with such things?

I started fixing up the kernel I could find for porting postmarketos to kindle dxg but wasn't 100% on what works and is fairly "safe" for developing.

https://gitlab.com/unrznbl/pmaports/...azon-kindledx/

Such as what is the equivalent on kindle dxg for fastboot/recovery and such.

I'll research more as I go of course but figured I'd start a thread to get quicker details from folks who know better than I.

Thanks in advance.

[NiLuJe]

The device is likely too underpowered to make anything modern remotely usable, unless you keep it CLI only, in which case, you don't really have to bother as it's already running Linux and getting a root shell is trivial?

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Otherwise, look at the Alpine images for K5 & up. Which are already dog slow, despite running on much more powerful hardware.

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Sidebar: You're absolute *NOT* going to be able to use anything other than Amazon's own kernel sources. Even on more modern devices, which are at least based on NXP's own kernel trees, rebasing against newer versions of said tree is a *massive* endeavor, and rebasing against anything more different than that is basically pure masochism.

You don't see a lot of custom kernels for consumer eInk devices, there's a reason for that .

[unrznbl]

Sure. My main goal is really to have stable usbnetwork and kvncserver. So I might poke at that.

Then again porting openfirmware would be fun right?

Is there some support in there somewhere like diagnostic tools are available right? Which would make flashing as it were fairly safe to iterate on?

Thanks again. Really. You are super helpful, no joke!

[NiLuJe]

Look at Kubrick, those are mostly unkillable, as long as you can get the tools to behave, which may prove to be the main issue here, because those things are old .

[unrznbl]

Got it. https://bitbucket.org/ixtab/kubrick Looks like a good place to start. Thank you.

[katadelos]

I've never worked with the older Kindles but there's a few tips I can pass on from working with the KT2 - there's a good chance that not all of these will be applicable to your device:

• Compile one of NiLuJe's toolchains (the version compatible with your device) and try to build and load some kernel modules before flashing a full kernel - doing this will give you some confidence and allow you to verify that your toolchain works correctly before you do anything that will be tricky to recover from
• Backup everything before you even think about flashing a self built kernel; you will thank yourself later if things go badly wrong
• It's a very, very good idea to have a serial cable permanently attached to your Kindle when messing around with the kernel + rootfs - it's likely that you'll brick your device at some point and being able to access it over serial will make life a lot easier
• If you're starting out, you will probably find it easiest to flash a new kernel using fastboot -
  you can enter fastboot mode from bist or by using the magic key+MfgTool+custom uboot combo (IIRC this is pretty much how Kubrick works)
• If the ancient kernel version on the DX supports the g_file_storage or g_multi kernel modules, you can directly flash your Kindle with dd without needing to enter fastboot in the first place

Once you've got your toolchain set up and have flashed a few custom kernels successfully, the process is a lot less scary. That said, the real struggle that you're going to face will not be running your own kernel - it'll be tweaking your chosen userspace to allow you to load the firmware blobs and waveforms required by the wifi/wan hardware + screen. Like NiLuJe said above, it's possible to run an Alpine Linux userspace within a chroot (or as a rootfs if you mess around the init scripts first), but you might be disappointed with how slowly it runs and the amount of additional work that'll be required to get all of the hardware vaguely working.