How does module_init(jpeg_init) get called

[Miles MH Chen]

Hello Michael,

The module_init call is defined as device_initcall, which is one of kernel
inicalls.
All initcalls are put to initcall section and kernel calls all initcalls at
boot time.

You can check this in your vmlinux:

ffffffff81765ed8 T __initcall_start
ffffffff81765ed8 T __setup_end
ffffffff81765ee0 t __initcall_trace_init_flags_sys_exitearly
ffffffff81765ee8 t __initcall_trace_init_flags_sys_enterearly
ffffffff81765ef0 t __initcall_init_hw_perf_eventsearly
ffffffff81765ef8 t __initcall_register_trigger_all_cpu_backtraceearly
ffffffff81765f00 t __initcall_spawn_ksoftirqdearly
ffffffff81765f08 t __initcall_init_workqueuesearly
ffffffff81765f10 t __initcall_check_cpu_stall_initearly
ffffffff81765f18 t __initcall_migration_initearly
...

kernel calls do_initcalls in do_basic_setup

783 static void __init
do_basic_setup(void)

784
{

785
cpuset_init_smp();

786
usermodehelper_init();

787
shmem_init();

788
driver_init();

789
init_irq_proc();

790
do_ctors();

791
usermodehelper_enable();

*792         do_initcalls();   *

793
random_int_secret_init();

794 }

Regards,
MH



On Thu, Jan 9, 2014 at 10:25 AM, m silverstri <
michael.j.silverstri at gmail.com> wrote:

> Hi,
>
> In a kernel driver code, I see it has 'module_init(jpeg_init)' and
> 'module_exit(jpeg_exit)'.  I would like how know how will
> jpeg_init(void) gets call during kernel bring up.
>
> As an example:
> static int __init jpeg_init(void)
> {
> printk(KERN_CRIT "Initialize JPEG driver\n");
>
> platform_driver_register(&jpeg_driver);
>
> return 0;
> }
>
> static void __exit jpeg_exit(void)
> {
> platform_driver_unregister(&jpeg_driver);
> }
>
> module_init(jpeg_init);
> module_exit(jpeg_exit);
>
> Thank you.
>
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> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
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>
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