Better kobo support by pcouy · Pull Request #238 · rmkit-dev/rmkit

pcouy · 2026-05-05T10:50:43Z

This branch contains a few tweaks I implemented after trying rmkit (more specifically remux) on my Elipsa 2E. The commits can be grouped into a few categories :

Build related changes : upgrade a docker image and add a missing CROSS_TC env var to a build script
Deal with some stability issues (remux going to stable 90% CPU use and not showing on gesture) by :
1. Letting me manually restart remux by killing any previously running instance in the wrapper script
2. Fixing an exception storm when using remux's API to show/hide it
Improve app switching by :
1. Changing the interface of perform_redraw(...) to have an optional second boolean parameter to control screen flashing with FBInk, and using it when showing/hiding remux. This fixed ghosting for me
2. Preventing nickel from grabbing inputs by grabbing them first, which let other apps detect rotation and power button presses on my Kobo Elipsa 2E (with this, I can have nickel and koreader running side by side, both working well with the remux flow)

This is a lot of different things, but I tried to make each commit as atomic as possible, and wrote detailed commit messages when the commit changed more than a couple of lines. I hope this helps with the review.

If needed, I can make a separate branch with only the commits you want to merge.

- Add kobo/ output dir to .gitignore - Fix `make remux_docker` and other similar targets for kobo => Build is a lot faster than rebuilding everything everytime

Updated the kobo wrapper script. Before this, I would sometimes have 2 remux instances running at the same time when testing, which caused weird issues. This is kind of a dirty hack that was quicker than finding the root cause

Before this, when sending commands through the API, stdout would fill with exceptions with the call eventually working. After a few calls, remux would crash. Changed the locking logic in `TaskQueue`, mainly by repurposing `task_m` (which I could not find the purpose of, or anywhere in the code that acquired this lock) to prevent having more than 1 task thread running at a time.

Updated method signatures for all backends, only implemented it for FBInk

Done by grabbing the inputs on first launch and releasing them only after the nickel process is running. Context : I added a modified version of koreader.sh to my remux, which does not kill nickel before launching koreader. The goal is to seamlessly switch between nickel and koreader, and to use bluetooth on y Elipsa 2E without fearing a wipe on my /mnt/onboard if I accidentaly restart nickel instead of rebooting the e-reader. This introduced an issue where koreader would not handle rotations or the power button because nickel grabs these devices and never releases them. WARNING : I have only tested this on my Kobo Elipsa 2E (Condor), this may break on other devices. Not sure why input grabbing was disabled by the preprocessor for Kobo target, but disabling it did not break anything on Condor. I also needed to add the `gpio` device to inputs, which emits orientation change events on my Condor. The `EV_MSC` + `MSC_RAW` filter might match other input devices on other e-readers. I think this would be harmless anyway, but is worth checking before merging

After commit 2fd7055 most apps would not build for the kobo target. Example build output below : ``` $ TARGET=kobo DOCKERFILE=Dockerfile.kobo FBINK=1 make harmony_docker CXX=arm-kobo-linux-gnueabihf-g++ okp -sh -ig "RMKIT_IMPLEMENTATION" -ns -ni -for -d ../.rmkit.h_cpp/ -o ../build/rmkit.h rmkit.cpy ../build/stb.arm.o -- -D"KOBO=1" -D"RMKIT_IMPLEMENTATION" -ldl -pthread -lpthread -fdata-sections -ffunction-sections -Wl,--gc-sections -L/rmkit/src/vendor/FBInk/Release -l:libfbink.a -D"RMKIT_FBINK=1" -O2 -static -static-libstdc++ -static-libgcc compile flags: -DKOBO=1 -DRMKIT_IMPLEMENTATION -ldl -pthread -lpthread -fdata-sections -ffunction-sections -Wl,--gc-sections -L/rmkit/src/vendor/FBInk/Release -l:libfbink.a -DRMKIT_FBINK=1 -O2 -static -static-libstdc++ -static-libgcc missing file: ../shared/proc.h missing file: ../shared/string.h generating single header /rmkit/src/rmkit/../build/rmkit.h MISSING FILE! /rmkit/src/.rmkit.h_cpp/shared/proc.h MISSING FILE! /rmkit/src/.rmkit.h_cpp/shared/string.h compiled into /rmkit/src/.rmkit.h_cpp missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/proc.h missing file: ../shared/string.h make[2]: Leaving directory '/rmkit/src/rmkit' make[1]: Leaving directory '/rmkit/src/rmkit' cd src/harmony && make make[1]: Entering directory '/rmkit/src/harmony' make compile_kobo make[2]: Entering directory '/rmkit/src/harmony' make[3]: Entering directory '/rmkit/src/vendor/FBInk' make[3]: Nothing to be done for 'staticlib'. make[3]: Leaving directory '/rmkit/src/vendor/FBInk' CXX=arm-kobo-linux-gnueabihf-g++ okp -ig "RMKIT_IMPLEMENTATION" -ns -ni -for -d ../.harmony_cpp/ -o ../build/harmony main.cpy ../build/stb.arm.o -- -D"KOBO=1" -D"RMKIT_IMPLEMENTATION" -ldl -pthread -lpthread -fdata-sections -ffunction-sections -Wl,--gc-sections -L/rmkit/src/vendor/FBInk/Release -l:libfbink.a -D"RMKIT_FBINK=1" -Wno-psabi -O2 -static -static-libstdc++ -static-libgcc compile flags: -DKOBO=1 -DRMKIT_IMPLEMENTATION -ldl -pthread -lpthread -fdata-sections -ffunction-sections -Wl,--gc-sections -L/rmkit/src/vendor/FBInk/Release -l:libfbink.a -DRMKIT_FBINK=1 -Wno-psabi -O2 -static -static-libstdc++ -static-libgcc arm-kobo-linux-gnueabihf-g++ -c /rmkit/src/.harmony_cpp/main.cpp -o /rmkit/src/.harmony_cpp/main.o -DKOBO=1 -DRMKIT_IMPLEMENTATION -ldl -pthread -lpthread -fdata-sections -ffunction-sections -Wl,--gc-sections -L/rmkit/src/vendor/FBInk/Release -l:libfbink.a -DRMKIT_FBINK=1 -Wno-psabi -O2 -static -static-libstdc++ -static-libgcc In file included from /rmkit/src/.harmony_cpp/main.cpp:3: /rmkit/src/.harmony_cpp/../build/rmkit.h: In lambda function: /rmkit/src/.harmony_cpp/../build/rmkit.h:22492:22: error: 'proc' has not been declared 22492 | auto procs = proc::list_procs(bins); | ^~~~ missing file: stb_image.h missing file: stb_image_resize.h Couldn't compile /rmkit/src/.harmony_cpp/main.cpp aborting compiled into /rmkit/src/.harmony_cpp make[2]: *** [../actions.make:42: compile_kobo] Error 1 make[2]: Leaving directory '/rmkit/src/harmony' make[1]: Leaving directory '/rmkit/src/harmony' make[1]: *** [../actions.make:11: compile] Error 2 make: *** [Makefile:18: harmony] Error 2 ```

pcouy · 2026-05-05T10:50:43Z

This branch contains a few tweaks I implemented after trying rmkit (more specifically remux) on my Elipsa 2E. The commits can be grouped into a few categories :

Build related changes : upgrade a docker image and add a missing CROSS_TC env var to a build script
Deal with some stability issues (remux going to stable 90% CPU use and not showing on gesture) by :
1. Letting me manually restart remux by killing any previously running instance in the wrapper script
2. Fixing an exception storm when using remux's API to show/hide it
Improve app switching by :
1. Changing the interface of perform_redraw(...) to have an optional second boolean parameter to control screen flashing with FBInk, and using it when showing/hiding remux. This fixed ghosting for me
2. Preventing nickel from grabbing inputs by grabbing them first, which let other apps detect rotation and power button presses on my Kobo Elipsa 2E (with this, I can have nickel and koreader running side by side, both working well with the remux flow)