[ECOS] Enabling Interrupts

[ECOS] Enabling Interrupts

[Christoph Csebits]

Hi,

i am working on an eCos port for a PowerPC MPC860T
based board. On the board is a simple "load and go"
bootstrapper doing simple board initialization.

Serial ports under eCos are not yet working, but
i have blinking leds (based on simple hello.c).

Then i started to try this with two threads.
My problem is, that enabling the interrupts
(in Cyg_Interrupt::enable_interrupts(); -> MSR[EE]=1)
never returns. 

Any idea, where to start?

best regards
Christoph

Re: [ECOS] Enabling Interrupts

[Linus Nielsen Feltzing]

It looks like a problem with your interrupts.
How are your vectors set up? Where are they located (interrupt prefix)?
It is probably the Decrementer interrupt that has triggered.

/Linus

----- Original Message ----- 
From: "Christoph Csebits" <Christoph.Csebits@frequentis.com>
To: <ecos-discuss@sources.redhat.com>
Sent: Thursday, April 26, 2001 11:57 AM
Subject: [ECOS] Enabling Interrupts


> Hi,
> 
> i am working on an eCos port for a PowerPC MPC860T
> based board. On the board is a simple "load and go"
> bootstrapper doing simple board initialization.
> 
> Serial ports under eCos are not yet working, but
> i have blinking leds (based on simple hello.c).
> 
> Then i started to try this with two threads.
> My problem is, that enabling the interrupts
> (in Cyg_Interrupt::enable_interrupts(); -> MSR[EE]=1)
> never returns. 
> 
> Any idea, where to start?
> 
> best regards
> Christoph
> 

Re: [ECOS] Enabling Interrupts

[Christoph Csebits]

On Thu, Apr 26, 2001 at 12:26:34PM +0200, Linus Nielsen Feltzing wrote:
> It looks like a problem with your interrupts.
> How are your vectors set up? Where are they located (interrupt prefix)?

Due to using not the ecos gdb stub to upload my applications the
exception vector table is not initialized/set up.

How can i configure eCos to set up the vector tables, and how
can i verify that they are put into the right memory location?

And is there anything to manage after the vector table is set up?
(registering some isr routines, or is it done automatically)

> It is probably the Decrementer interrupt that has triggered.
you are right, it was the Decrementer interrupt.

prehistory:
> > Hi,
> > 
> > i am working on an eCos port for a PowerPC MPC860T
> > based board. On the board is a simple "load and go"
> > bootstrapper doing simple board initialization.
> > 
> > Serial ports under eCos are not yet working, but
> > i have blinking leds (based on simple hello.c).
> > 
> > Then i started to try this with two threads.
> > My problem is, that enabling the interrupts
> > (in Cyg_Interrupt::enable_interrupts(); -> MSR[EE]=1)
> > never returns. 
> > 
> > Any idea, where to start?
> > 
> > best regards
> > Christoph
> > 
best regards, Christoph

Re: [ECOS] Enabling Interrupts

[Gary Thomas]

On 02-May-2001 Christoph Csebits wrote:
> On Thu, Apr 26, 2001 at 12:26:34PM +0200, Linus Nielsen Feltzing wrote:
>> It looks like a problem with your interrupts.
>> How are your vectors set up? Where are they located (interrupt prefix)?
> 
> Due to using not the ecos gdb stub to upload my applications the
> exception vector table is not initialized/set up.
> 
> How can i configure eCos to set up the vector tables, and how
> can i verify that they are put into the right memory location?
> 

Set  CYGSEM_HAL_POWERPC_COPY_VECTORS

> And is there anything to manage after the vector table is set up?
> (registering some isr routines, or is it done automatically)
> 
>> It is probably the Decrementer interrupt that has triggered.
> you are right, it was the Decrementer interrupt.
> 
> prehistory:
>> > Hi,
>> > 
>> > i am working on an eCos port for a PowerPC MPC860T
>> > based board. On the board is a simple "load and go"
>> > bootstrapper doing simple board initialization.
>> > 
>> > Serial ports under eCos are not yet working, but
>> > i have blinking leds (based on simple hello.c).
>> > 
>> > Then i started to try this with two threads.
>> > My problem is, that enabling the interrupts
>> > (in Cyg_Interrupt::enable_interrupts(); -> MSR[EE]=1)
>> > never returns. 
>> > 
>> > Any idea, where to start?
>> > 
>> > best regards
>> > Christoph
>> > 
> best regards, Christoph

Re: [ECOS] Enabling Interrupts

[Hugo Tyson]

Christoph Csebits <Christoph.Csebits@frequentis.com> writes:
> i am working on an eCos port for a PowerPC MPC860T
> based board. On the board is a simple "load and go"
> bootstrapper doing simple board initialization.
> 
> Serial ports under eCos are not yet working, but
> i have blinking leds (based on simple hello.c).
> 
> Then i started to try this with two threads.
> My problem is, that enabling the interrupts
> (in Cyg_Interrupt::enable_interrupts(); -> MSR[EE]=1)
> never returns. 
> 
> Any idea, where to start?

You probably have an interrupt loop; ie. some source is interrupting and
there is no handler, so the CPU spins being interrupted constantly.  Or
it's hung up trying to use the serial, or something.  If you had a serial
port you might see the results of this code from hal_misc.c (so long as
you're not using VIRTUAL_VECTOR_SUPPORT when an empty routine is used
instead):

externC cyg_uint32
hal_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
    diag_printf("Interrupt: %d\n", vector);

    CYG_FAIL("Spurious Interrupt!!!");
    return 0;
}

You could modify that to diddle your LEDs and loop forever so you know it
was in there; print the interrupt vector number in LEDflashes.  Track down
the hardware that's on that interrupt number and shut it down and mask its
interrupt during startup so it's not interrupting and you can move onto the
next inexplicable crash ;-)

HTH,
	- Huge