hello,
Anybody here could please explain to me how __setup macro works?
For example, in drivers/block/loop.c, we have
__setup("max_loop=", max_loop_setup)
After some investigation, I see that __setup is a macro that defines a
static struct obs_kernel_param, as in its definition:
#define __setup_param(str, unique_id, fn, early) \
static char __setup_str_##unique_id[] __initdata = str; \
static struct obs_kernel_param __setup_##unique_id \
__attribute_used__ \
__attribute__((__section__(".init.setup"))) \
__attribute__((aligned((sizeof(long))))) \
= { __setup_str_##unique_id, fn, early }
#define __setup(str, fn) \
__setup_param(str, fn, fn, 0)
Things look fine, but the problem is how obs_kernel_param is used? I
guess the function fn (as in the above example, is "max_loop_setup")
will be called somewhere, but I dont see how it is called (?)
All the helps are appreciated.
Thank you,
Hieu
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