RajKumar Rampelli RajKumar Rampelli - 6 months ago 15
Linux Question

How to get details of all modules/drivers got initialized/probed during kernel boot

I need the sequence of modules/drivers that are invoked|initialized|probed during the kernl boot.

Can you please let me know if any flash command-line option available to get this sequence ?

Answer

Passing the option "initcall_debug" on the kernel command line will cause timing information to be printed to the console for each init routine of built-in drivers. The initcalls are used to initialize statically linked kernel drivers and subsystems and contribute a significant amount of time to the Linux boot process. (Loadable modules are not available until after the root filesystem has been mounted.)

The output looks like:

calling  tty_class_init+0x0/0x44 @ 1
initcall tty_class_init+0x0/0x44 returned 0 after 9765 usecs
calling  spi_init+0x0/0x90 @ 1
initcall spi_init+0x0/0x90 returned 0 after 9765 usecs

Reference: http://elinux.org/Initcall_Debug