Re: booting the kernel

["Shyamal Shukla" <shyamalshukla@xxxxxxxxx>]

Hi,

       Some further questions on the same issue. At the time of kernel initialization, we have several set_trap_gate() and set_system_gate() function calls. As i understand, in case of x86, each of these shall install an entry in the Interrupt Descriptor Table at a particular index.

When the same interrupt occurs, the entry in IDT shall provide the Segment Selector and the offset in the segment, at which the interrupt handler code can be found. 

If the above understanding is correct, what role do the multiple ENTRY() linker script directives have to play in entry.S?

Regards,
Shyamal

On Tue, Apr 22, 2008 at 7:15 AM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote:

Hi

On Mon, Apr 21, 2008 at 3:58 PM, Shyamal Shukla <shyamalshukla@xxxxxxxxx> wrote:
> Hi Mulyadi,
>
>      I saw a post initiated by you regarding the entry.S file
>
>  http://mail.nl.linux.org/kernelnewbies/2005-11/msg00161.html

Ahhhh :)

>  I am stuck with the same doubt (the need for multiple entry points and when
> and how will each one of them be activated).

Short answer to trigger your own further research: because x86...and
so do many other processor's architectures...provide so many
interrupts, trap and exceptions. Each of them needs to be handled
properly.

Think about division by zero, segmentation fault and so on...

>  Some detailed explanation or pointers, shall be of great help.

I think LDD3 will provide you better background here... or buy a copy
of Understanding of Linux Kernel 3rd ed.

regards,

Mulyadi.

-- 
Linux - because life is too short for reboots...