bdi2000 + mpc8560ads, very early breakpoints

bdi2000 + mpc8560ads, very early breakpoints

[Kylo Ginsberg]

I'm running a bdi2000 (with mpc85xx-gdb f/w 1.03) with a mpc8560ads 
target, and I'm trying to set breakpoints early on in linux startup (in 
the head_e500.S code that sets up tlb's).   I'm setting the breakpoints 
from within the bdi telnet interface.

I can:
--succesfully hit a breakpoint set up to any instruction <= the address 
of the first 'tlbwe'.
--single step (with the bdi "TI" command) past that 'tlbwe' as far as 
I've cared to try

I cannot:
--hit a breakpoint once the first 'tlbwe' has executed.  If I attempt to 
do so, linux startup doesn't proceed, I lose further communication with 
the target and the BDI claims "COP Freeze" and I have to reset the target.

Btw, the 'tlbwe' in question marks invalid the first tlb1 entry setup by 
u-boot, which pointed at flash address space.  Code is running out of 
ram at this point.

I'm probably missing something very basic here.  Any ideas?

Thanks,
Kylo

RE: bdi2000 + mpc8560ads, very early breakpoints

[Fahd Abidi]

Try the suggestions pointed out in here:

http://www.ultsol.com/faq-P308.htm

This is based off suggestions from another customer. Let me know if this
works for you or not.

Fahd

-----Original Message-----
From: Kylo Ginsberg [mailto:kylo@veriwave.com]=20
Sent: Tuesday, April 12, 2005 3:21 PM
To: linuxppc-embedded@ozlabs.org
Subject: bdi2000 + mpc8560ads, very early breakpoints

I'm running a bdi2000 (with mpc85xx-gdb f/w 1.03) with a mpc8560ads=20
target, and I'm trying to set breakpoints early on in linux startup (in=20
the head_e500.S code that sets up tlb's).   I'm setting the breakpoints=20
from within the bdi telnet interface.

I can:
--succesfully hit a breakpoint set up to any instruction <=3D the =
address=20
of the first 'tlbwe'.
--single step (with the bdi "TI" command) past that 'tlbwe' as far as=20
I've cared to try

I cannot:
--hit a breakpoint once the first 'tlbwe' has executed.  If I attempt to

do so, linux startup doesn't proceed, I lose further communication with=20
the target and the BDI claims "COP Freeze" and I have to reset the
target.

Btw, the 'tlbwe' in question marks invalid the first tlb1 entry setup by

u-boot, which pointed at flash address space.  Code is running out of=20
ram at this point.

I'm probably missing something very basic here.  Any ideas?

Thanks,
Kylo

_______________________________________________
Linuxppc-embedded mailing list
Linuxppc-embedded@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-embedded

Re: bdi2000 + mpc8560ads, very early breakpoints

[Kylo Ginsberg]

Thanks; that was instructive.  I hadn't read up on the 85xx debug 
exceptions yet.

For posterity, my issue was that even though the code is running out of 
ddr at this stage, u-boot has left the IVPR pointed at flash.  So once 
head_e500.S invalidated the tlb entry for the flash region, the debug 
exception vector was inaccessible and a breakpoint sent the processor 
off the road.  As a workaround, I modified u-boot to re-point IVPR when 
it relocates itself into ddr.

Cheers,
Kylo

Fahd Abidi wrote:

>Try the suggestions pointed out in here:
>
>http://www.ultsol.com/faq-P308.htm
>
>This is based off suggestions from another customer. Let me know if this
>works for you or not.
>
>Fahd
>
>-----Original Message-----
>From: Kylo Ginsberg [mailto:kylo@veriwave.com] 
>Sent: Tuesday, April 12, 2005 3:21 PM
>To: linuxppc-embedded@ozlabs.org
>Subject: bdi2000 + mpc8560ads, very early breakpoints
>
>I'm running a bdi2000 (with mpc85xx-gdb f/w 1.03) with a mpc8560ads 
>target, and I'm trying to set breakpoints early on in linux startup (in 
>the head_e500.S code that sets up tlb's).   I'm setting the breakpoints 
>from within the bdi telnet interface.
>
>I can:
>--succesfully hit a breakpoint set up to any instruction <= the address 
>of the first 'tlbwe'.
>--single step (with the bdi "TI" command) past that 'tlbwe' as far as 
>I've cared to try
>
>I cannot:
>--hit a breakpoint once the first 'tlbwe' has executed.  If I attempt to
>
>do so, linux startup doesn't proceed, I lose further communication with 
>the target and the BDI claims "COP Freeze" and I have to reset the
>target.
>
>Btw, the 'tlbwe' in question marks invalid the first tlb1 entry setup by
>
>u-boot, which pointed at flash address space.  Code is running out of 
>ram at this point.
>
>I'm probably missing something very basic here.  Any ideas?
>
>Thanks,
>Kylo
>
>_______________________________________________
>Linuxppc-embedded mailing list
>Linuxppc-embedded@ozlabs.org
>https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
>_______________________________________________
>Linuxppc-embedded mailing list
>Linuxppc-embedded@ozlabs.org
>https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
>  
>

Re: bdi2000 + mpc8560ads, very early breakpoints

[Wolfgang Denk]

In message <425D6C03.1070805@kylo.net> you wrote:
> 
> off the road.  As a workaround, I modified u-boot to re-point IVPR when 
> it relocates itself into ddr.

Will you submit a patch to the U-Boot mailing list, please?

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
I think there's a world market for about five computers.
         -- attr. Thomas J. Watson (Chairman of the Board, IBM), 1943