m68302 boot problem - newbie!!!

[Nicco]

I don't think this a timer problem because I just deleted the 3 suspect
lines before the problematic JSR instruction, and this problem seems
almost solved, the board contiues to boot. But I still don't know the
purpose of these instructions... Anyway, thank you very much for your
reply !!
 
 
 
-----Original Message-----
From: Steven Grunza [mailto:steven_grunza at ieee.org] 
Sent: mercredi 7 mai 2003 16:48
To: pigeon.nicolas at wanadoo.fr
Subject: Re: m68302 boot problem - newbie!!!
 
This is just a shot in the dark but does the 68302 have a watchdog 
timer?  If it does is it timing out?
 
Another thing I've seen happen is a periodic timer timing out before the

ISR that handles it is installed.  I've been bit with this on PowerPC
with 
the DECrementer.
 
PS
   I haven't used the 68302 but thought I'd contribute my USD 0.02
 
At 02:15 PM 5/7/2003 +0200, you wrote:
>Hi,
>
>I'm working on a home made board made of a m68302, 512 ko RAM on CS1 
>and 1
>Mo Eprom on CS0, and I have two problems I'm unable to solve...
>I (try to) use RedHat 7.3 and RTEMS 4.5.0, and my work is based on the 
>ods68302 BSP which seems very close to mine. And here's my first
problem: 
>everything boots fine until the 68302 reaches the code needed to copy
the 
>.data section into RAM. Indeed, the origin and destination addresses
are 
>the same, and located in the Eprom. I guess it's a linker problem, but
the 
>linker script seems OK (I did not modify it), and I can't locate the 
>problem. Does anybody have a little idea or suggestion please? This
work 
>is important to me because I'm still a student and I may not be
graduated 
>if I fail my internship...
>Then the second problem (the first one does not make the card hang, and

>it's still working... but not for a long time :-(): when the 68302
reaches 
>a JSR instruction to jump to the "boot_phase_3" subroutine, it indeed 
>jumps at the right place, but it only reads the first byte of the next 
>instruction (which is a JSR too), and then the address bus goes to
FFFFF, 
>and that's it! Here's the assembly code just before and after the
problem:
>        movel        %d0,_stack_init                       |do=0 here,
and 
> _stack_init is at the end of .bss
>        movew     #0x3700, %sr                          |supervisor
mode, 
> all interrupts off
>        movel       %d0, %a7                                 |set
master 
> stack pointer
>        movel       %d0, %a6                                 |set base
pointer
>        jsr            boot_phase_3
>   The jump is OK, at the right place, where there is
>        jsr            debug_port_banner
>This instruction is not even read until its end  (3 bytes long, only
the 
>first is read), and the adress bus goes to FFFFF. The 68302 doesn't
even 
>try to go to an exception vector...
>I would really appreciate any help or ideas, it would save me!!
>
>Thanks
 
 
 
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