Originally Posted by ixtab
There is a reason why there are comparatively few hacks for the KT at the moment, and why many are low-level: the device is still new, and devs obviously focus on the most important aspects first. "Important" is highly subjective of course. Remember that this is all spare-time fun hacking, so everyone is tackling what they find most interesting or useful. ....
In the case of "native mode" (arm machine code) programs that output to the eInk display (like the onscreen terminal), the programs designed for the K3 and earlier generally seem to assume that the display framebuffer uses 4 bits-per-pixel. The K4 and newer use 8 bits-per-pixel, and the touch usually has an extra 8 bytes of unused memory at the end of each row of pixels (but not always). The eInk drivers support multiple modes, and it is not always safe to assume anything about the layout. You can do "eips -i" to get information about the current display mode.
For very simple script-level (/bin/sh) eInk support, I have been using the "eips" command (for a lot more than its "eips -i" features). And eips works on the older kindles too.
For a couple of examples of using eips (along with hexdump and dd) for direct control of the eink framebuffer (and reading device input events like touchscreen), look at these very simple scripts:
K4 and Touch (ddplot): https://www.mobileread.com/forums/sho....php?p=1997659
Touch (touchpaint): https://www.mobileread.com/forums/sho....php?p=1989102
said, this is a hobby, so ENJOY the time you spend doing this stuff!
I learned a lot while developing the techniques used in the scripts at the above links (especially how to simplify and speed up the code, while using only the latest script features that work in the busybox shell supplied in the kindles, while reducing calls to external processes like "sed" and "cut"). I hope you find some of the techniques I discovered to be valuable in your future "script kiddie" kindle exploits.