blob-cvs-commit

interrupt handler in blob

[Abraham vd M. <ab...@2d...>]

Hi!

I'm beating my head against a stone here :P

If I set the irq exception handler to any address in a
INIT_LEVEL_DRIVER_SELECTION hook and I check that address later on in a
INIT_LEVEL_OTHER_STUFF hook, the address differs, e.g. with

static void frodo_set_irq()
{
   u32 *irq_vector =3D (u32 *) 0x00000018;
   *irq_vector =3D 0xdeadbeaf;  =20
}
__initlist(frodo_set_irq,INIT_LEVEL_DRIVER_SELECTION);

static void frodo_debug_irq()
{
   u32 *irq_vector =3D (u32 *) 0x00000018;
   printf ("*irq_vector =3D=3D 0x%.8x\n",*irq_vector);  =20
}
__initlist(frodo_debug_irq,INIT_LEVEL_OTHER_STUFF);

I get *irq_vector =3D=3D 0xea0000c1 when booting blob.

I can't see anything in the second stage boot loader that modifies this
address, so what is happening here?

--=20

Regards
 Abraham

"Kill the Wabbit, Kill the Wabbit, Kill the Wabbit!"
-- Looney Tunes, "What's Opera Doc?" (1957, Chuck Jones)

__________________________________________________________
 Abraham vd Merwe - 2d3D, Inc.

 Device Driver Development, Outsourcing, Embedded Systems

  Cell: +27 82 565 4451         Snailmail:
   Tel: +27 21 761 7549            Block C, Aintree Park
   Fax: +27 21 761 7648            Doncaster Road
 Email: ab...@2d...         Kenilworth, 7700
  Http: http://www.2d3d.com        South Africa

Re: interrupt handler in blob

[Russ D. <Rus...@as...>]

didn't we already go over the whole thing about having a watchdog
running in the bootloader is bad? or are you trying to do something
else, its late, I'm confused easily

Re: interrupt handler in blob

[Abraham vd M. <ab...@2d...>]

Hi Russ!

> didn't we already go over the whole thing about having a watchdog
> running in the bootloader is bad? or are you trying to do something
> else, its late, I'm confused easily

It is still for the watchdog. I can change the watchdog in version 2, but
for now I need an interrupt handler in blob

--=20

Regards
 Abraham

No one knows like a woman how to say things that are at once gentle and dee=
p.
		-- Hugo

__________________________________________________________
 Abraham vd Merwe - 2d3D, Inc.

 Device Driver Development, Outsourcing, Embedded Systems

  Cell: +27 82 565 4451         Snailmail:
   Tel: +27 21 761 7549            Block C, Aintree Park
   Fax: +27 21 761 7648            Doncaster Road
 Email: ab...@2d...         Kenilworth, 7700
  Http: http://www.2d3d.com        South Africa

Re: interrupt handler in blob

[Erik M. <J.A...@it...>]

On Thu, Apr 25, 2002 at 12:33:34PM +0200, Abraham vd Merwe wrote:
> I'm beating my head against a stone here :P
> 
> If I set the irq exception handler to any address in a
> INIT_LEVEL_DRIVER_SELECTION hook and I check that address later on in a
> INIT_LEVEL_OTHER_STUFF hook, the address differs, e.g. with
> 
> static void frodo_set_irq()
> {
>    u32 *irq_vector = (u32 *) 0x00000018;
>    *irq_vector = 0xdeadbeaf;   

You're trying to write to flash...

> }
> __initlist(frodo_set_irq,INIT_LEVEL_DRIVER_SELECTION);
> 
> static void frodo_debug_irq()
> {
>    u32 *irq_vector = (u32 *) 0x00000018;
>    printf ("*irq_vector == 0x%.8x\n",*irq_vector);   
> }
> __initlist(frodo_debug_irq,INIT_LEVEL_OTHER_STUFF);
> 
> I get *irq_vector == 0xea0000c1 when booting blob.
> 
> I can't see anything in the second stage boot loader that modifies this
> address, so what is happening here?

Writing to flash doesn't work. Do it like I suggested before: "irq" in
start-sa11x0.S has to become an indirect branch to an entry point in
trampoline.S. The entry point in trampoline.S on its turn can push some
registers on the stack and branch&link into the C irq handler.


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty
of Information Technology and Systems, Delft University of Technology,
PO BOX 5031, 2600 GA Delft, The Netherlands  Phone: +31-15-2783635
Fax: +31-15-2781843  Email: J.A...@it...
WWW: http://www-ict.its.tudelft.nl/~erik/