Message-ID: <20020816072109.53259.qmail@web12407.mail.yahoo.com>
Date: Fri, 16 Aug 2002 00:21:09 -0700 (PDT)
From: Amol Lad <dal_loma@yahoo.com>
Subject: SMP boot query
To: linux-kernel@vger.kernel.org
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1323
Lines: 47

Hi,
 Lets assume, boot processor has done all its
initialization and is booting the second processor. 
In do_boot_cpu(), it calls fork_by_hand() and creates
an idle task for cpu#2 . 
It then iniliazes all relevant fields of 'idle' task
for cpu#2.
It also does following
start_eip = setup_trampoline();
stack_start.esp = (void *) (1024 + PAGE_SIZE + (char
*)idle);

After doing lot of APIC related stuff, it sends
Startup IPI to cpu#2 to start booting from start_eip .


cpu#2, from trampoline code jumps to startup_32 and
from there to initialize_secondary. 

initialize_secondary is

        asm volatile(
                "movl %0,%%esp\n\t"
                "jmp *%1"
                :
                :"r" (current->thread.esp),"r"
(current->thread.eip));

Now my questions
1] what is trampoline ?
2] I did not understood, how 'current' above is set to
  new idle task created in fork_by_hand (is some magic
done in start_stack.esp ?? )

-- Amol


__________________________________________________
Do You Yahoo!?
HotJobs - Search Thousands of New Jobs
http://www.hotjobs.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/