asmlinkage void __init start_kernel(void)

    -->sort_main_extable();

        -->sort_extable(__start___ex_table, __stop___ex_table);

            -->sort(start, finish - start, sizeof(struct exception_table_entry),cmp_ex, NULL);

/*

 * The exception table consists of pairs of addresses: the first is the

 * address of an instruction that is allowed to fault, and the second is

 * the address at which the program should continue.  No registers are

 * modified, so it is entirely up to the continuation code to figure out

 * what to do.

 *

 * All the routines below use bits of fixup code that are out of line

 * with the main instruction path.  This means when everything is well,

 * we don't even have to jump over them.  Further, they do not intrude

 * on our cache or tlb entries.

 */

struct exception_table_entry

{

    unsigned long insn, fixup;

};

         * The exception fixup table (might need resorting at runtime)

         */

        . = ALIGN();

        __start___ex_table = .;

#ifdef CONFIG_MMU

        *(__ex_table)

#endif

        __stop___ex_table = .;