Hi sandeep, On Tue, Jul 26, 2011 at 2:05 AM, sandeep kumar <coolsandyforyou@gmail.com> wrote:

Hi all,

In kernel code at lot of places i came across "early_param("string", function_name)"

Eg: early_param("vmalloc", early_vmalloc); in arch/arm/mm/mmu.c

when this function will be called? and what is the significance of the string "vmalloc" there?

This function is called from here: http://lxr.linux.no/linux+v3.0/init/main.c#L378 In particular, it looks for the string "vmalloc" on the kernel command line, and if it finds it, then it will call early_vmalloc. early_params are processed early in the boot process, at a time when most services haven't yet been initialized. http://lxr.linux.no/linux+v3.0/Documentation/driver-model/platform.txt#L173 Most of the kernel command line options are documented here: http://lxr.linux.no/linux+v3.0/Documentation/kernel-parameters.txt with vmalloc in particular being here: http://lxr.linux.no/linux+v3.0/Documentation/kernel-parameters.txt#L2645 -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com