===== Overview =====

Ongoing notes for Madieu's book.




===== FIGURE OUT =====

==== General ====

  * How CONFIG_EXTRA_FIRMWARE_DIR is used.
  * Difference between ARM toolchains.
  * make xconfig (PKG_CONFIG_PATH)
  * scripts/cleanfile

==== Modules ====

  * /etc/modules-load.d/<filename>.conf
    * systemd-modules-load.service
    * man modules-load.d
  * /etc/modprobe.d/

==== Error handling ====

  * IS_ERR(), IS_ERR_VALUE(), PTR_ERR(), more (''err.h'')
  * console logging

==== Sleeping mechanisms ====

  * wait queues

==== Delays/timer management ====

  * programmable interrupt timer (PIT)
  * [[https://stackoverflow.com/questions/10812858/how-to-use-timers-in-linux-kernel-device-drivers]]
  * [[https://lwn.net/Articles/735887/]]
  * from_timer() [timer.h]