declaration & initialisation of a global & local variable. (linux)

global variable:

In C global variables are stored in data segment ,
if variable is only declared & not initialised with some value :  that variable is stored in BSS(block startup symbol) segment which is starting address of data segment where it is initialised with value '0' with a logical address.When we assign some value to it then it will move to main data segment .
if variable is assigned value at time of declaration : it directly moves to main data segment with some physical addressing.

local variables:

Local variables are stored in stack segment of process context
if variable is only declared & not initialised with some value: logical address is given to the variable like if we initialise "int val" then only 4 bytes or 8bytes (depending on compiler) with starting logical address is given to the variable.But physical addressing is provided by kernel at the time we assign some value to variable.