I am new to fenix and trying to optimize my 4.9.y kernel for faster boot on VIM3.
I am compiling ubuntu for SD on a Ubuntu 20.04 host. Initially, everything compiles and the SD card works great.
After I edit the kernel source or .dts files, and I type “make” in fenix/, the kernel is recompiled and the SD image rebuilt, but after flashing to SD and checking the dates, the kernel’s dates are still the ones of the first compilation (before my edits). If I boot the card, my changes are not run.
I tried to run “make distclean” in fenix/linux/ and then “make” in fenix, which now recompiles the whole kernel but the SD card still contains the old kernel and dtb files.
If I run “make clean” in fenix and then “make”, the kernel is updated on SD, but this takes 40 minutes each time.
How can I update the kernel on SD without a full “make clean” of fenix?