[ECOS] exception when calling reset_platform

[ECOS] exception when calling reset_platform

[Roland Caßebohm]

Hi,

my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when the 
application calls reset_platform().

I added two nop's because I thought the processor prefetches the init_done 
value, but this doesn't help:

----------
        .global reset_platform
        .type   reset_platform,function
reset_platform:
#ifdef CYGSEM_HAL_ROM_MONITOR
        // initialize CPSR (machine state register)
        mov     r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE)
        msr     cpsr,r0
        b       warm_reset
#else
        mov     r0,#0
        mov     pc,r0           // Jump to reset vector
        //roland
        mov     r0,r0           // nop
        mov     r0,r0           // nop
#endif

init_done:
        .long   0xDEADB00B
----------

Does anybody know what's wrong?

Roland

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Re: [ECOS] exception when calling reset_platform

[Iztok Zupet]

On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> Hi,
>
> my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when the
> application calls reset_platform().
>
> I added two nop's because I thought the processor prefetches the init_done
> value, but this doesn't help:
>
> ----------
>         .global reset_platform
>         .type   reset_platform,function
> reset_platform:
> #ifdef CYGSEM_HAL_ROM_MONITOR
>         // initialize CPSR (machine state register)
>         mov    
> r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE) msr    
> cpsr,r0
>         b       warm_reset
> #else
>         mov     r0,#0
>         mov     pc,r0           // Jump to reset vector
>         //roland
>         mov     r0,r0           // nop
>         mov     r0,r0           // nop
> #endif
>
> init_done:
>         .long   0xDEADB00B
> ----------
>
> Does anybody know what's wrong?
>
> Roland

Hi:

  Looks like that the abort prefetch hapens somewhere else, not in the code 
You've sent. Take a look at the reset vector and the code that executes there 
( if it is in RAM). It may be corrupt for some reason. Anyhow, can You figure 
out the address of the exeption?

iz


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Re: [ECOS] exception when calling reset_platform

[Roland Caßebohm]

On Thursday, 13. June 2002 19:16, Iztok Zupet wrote:
> On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> > Hi,
> >
> > my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when the
> > application calls reset_platform().
> >
> > I added two nop's because I thought the processor prefetches the
> > init_done value, but this doesn't help:
> >
> > ----------
> >         .global reset_platform
> >         .type   reset_platform,function
> > reset_platform:
> > #ifdef CYGSEM_HAL_ROM_MONITOR
> >         // initialize CPSR (machine state register)
> >         mov
> > r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE) msr
> > cpsr,r0
> >         b       warm_reset
> > #else
> >         mov     r0,#0
> >         mov     pc,r0           // Jump to reset vector
> >         //roland
> >         mov     r0,r0           // nop
> >         mov     r0,r0           // nop
> > #endif
> >
> > init_done:
> >         .long   0xDEADB00B
> > ----------
> >
> > Does anybody know what's wrong?
> >
> > Roland
>
> Hi:
>
>   Looks like that the abort prefetch hapens somewhere else, not in the code
> You've sent. Take a look at the reset vector and the code that executes
> there ( if it is in RAM). It may be corrupt for some reason. Anyhow, can
> You figure out the address of the exeption?
>
> iz

The exception seems to be at 0x31638:

void vs_reboot(void)
{
   
    ...

   31638:       ebffbb55        bl      20394 <reset_platform>
}
   3163c:       e91ba800        ldmdb   r11, {r11, sp, pc}


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Re: [ECOS] exception when calling reset_platform

[Iztok Zupet]

On Friday 14 June 2002 12:45, Roland Caßebohm wrote:
> On Thursday, 13. June 2002 19:16, Iztok Zupet wrote:
> > On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> > > Hi,
> > >
> > > my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when the
> > > application calls reset_platform().
> > >
> > > I added two nop's because I thought the processor prefetches the
> > > init_done value, but this doesn't help:
> > >
> > > ----------
> > >         .global reset_platform
> > >         .type   reset_platform,function
> > > reset_platform:
> > > #ifdef CYGSEM_HAL_ROM_MONITOR
> > >         // initialize CPSR (machine state register)
> > >         mov
> > > r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE) msr
> > > cpsr,r0
> > >         b       warm_reset
> > > #else
> > >         mov     r0,#0
> > >         mov     pc,r0           // Jump to reset vector
> > >         //roland
> > >         mov     r0,r0           // nop
> > >         mov     r0,r0           // nop
> > > #endif
> > >
> > > init_done:
> > >         .long   0xDEADB00B
> > > ----------
> > >
> > > Does anybody know what's wrong?
> > >
> > > Roland
> >
> > Hi:
> >
> >   Looks like that the abort prefetch hapens somewhere else, not in the
> > code You've sent. Take a look at the reset vector and the code that
> > executes there ( if it is in RAM). It may be corrupt for some reason.
> > Anyhow, can You figure out the address of the exeption?
> >
> > iz
>
> The exception seems to be at 0x31638:
>
> void vs_reboot(void)
> {
>
>     ...
>
>    31638:       ebffbb55        bl      20394 <reset_platform>
> }
>    3163c:       e91ba800        ldmdb   r11, {r11, sp, pc}

Strange. Since the abort prefetch happens here (it happens only beacuse of the 
ABORT signal asserted) it means that <reset_platform> is no longer in valid 
memory that can be reached by cpu. What kind of memory mapping do You have? 
Take a look at the linker xxx.ldi script in the platform/hal directory if 
they if it's correct for  Your memory layout.

iz

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Re: [ECOS] exception when calling reset_platform

[Roland Caßebohm]

On Friday, 14. June 2002 14:05, Iztok Zupet wrote:
> On Friday 14 June 2002 12:45, Roland Caßebohm wrote:
> > On Thursday, 13. June 2002 19:16, Iztok Zupet wrote:
> > > On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> > > > Hi,
> > > >
> > > > my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when
> > > > the application calls reset_platform().
> > > >
> > > > I added two nop's because I thought the processor prefetches the
> > > > init_done value, but this doesn't help:
> > > >
> > > > ----------
> > > >         .global reset_platform
> > > >         .type   reset_platform,function
> > > > reset_platform:
> > > > #ifdef CYGSEM_HAL_ROM_MONITOR
> > > >         // initialize CPSR (machine state register)
> > > >         mov
> > > > r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE) msr
> > > > cpsr,r0
> > > >         b       warm_reset
> > > > #else
> > > >         mov     r0,#0
> > > >         mov     pc,r0           // Jump to reset vector
> > > >         //roland
> > > >         mov     r0,r0           // nop
> > > >         mov     r0,r0           // nop
> > > > #endif
> > > >
> > > > init_done:
> > > >         .long   0xDEADB00B
> > > > ----------
> > > >
> > > > Does anybody know what's wrong?
> > > >
> > > > Roland
> > >
> > > Hi:
> > >
> > >   Looks like that the abort prefetch hapens somewhere else, not in the
> > > code You've sent. Take a look at the reset vector and the code that
> > > executes there ( if it is in RAM). It may be corrupt for some reason.
> > > Anyhow, can You figure out the address of the exeption?
> > >
> > > iz
> >
> > The exception seems to be at 0x31638:
> >
> > void vs_reboot(void)
> > {
> >
> >     ...
> >
> >    31638:       ebffbb55        bl      20394 <reset_platform>
> > }
> >    3163c:       e91ba800        ldmdb   r11, {r11, sp, pc}
>
> Strange. Since the abort prefetch happens here (it happens only beacuse of
> the ABORT signal asserted) it means that <reset_platform> is no longer in
> valid memory that can be reached by cpu. What kind of memory mapping do You
> have? Take a look at the linker xxx.ldi script in the platform/hal
> directory if they if it's correct for  Your memory layout.
>
> iz

RAM is mapped to 0x0 and the size is 0x200000. The function reset_platform 
should be and is in this array (0x20394).

Roland

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and search the list archive: http://sources.redhat.com/ml/ecos-discuss

Re: [ECOS] exception when calling reset_platform

[Iztok Zupet]

On Friday 14 June 2002 14:41, Roland Caßebohm wrote:
> On Friday, 14. June 2002 14:05, Iztok Zupet wrote:
> > On Friday 14 June 2002 12:45, Roland Caßebohm wrote:
> > > On Thursday, 13. June 2002 19:16, Iztok Zupet wrote:
> > > > On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> > > > > Hi,
> > > > >
> > > > > my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when
> > > > > the application calls reset_platform().
> > > > >
> > > > > I added two nop's because I thought the processor prefetches the
> > > > > init_done value, but this doesn't help:
> > > > >
> > > > > ----------
> > > > >         .global reset_platform
> > > > >         .type   reset_platform,function
> > > > > reset_platform:
> > > > > #ifdef CYGSEM_HAL_ROM_MONITOR
> > > > >         // initialize CPSR (machine state register)
> > > > >         mov
> > > > > r0,#(CPSR_IRQ_DISABLE|CPSR_FIQ_DISABLE|CPSR_SUPERVISOR_MODE) msr
> > > > > cpsr,r0
> > > > >         b       warm_reset
> > > > > #else
> > > > >         mov     r0,#0
> > > > >         mov     pc,r0           // Jump to reset vector
> > > > >         //roland
> > > > >         mov     r0,r0           // nop
> > > > >         mov     r0,r0           // nop
> > > > > #endif
> > > > >
> > > > > init_done:
> > > > >         .long   0xDEADB00B
> > > > > ----------
> > > > >
> > > > > Does anybody know what's wrong?
> > > > >
> > > > > Roland
> > > >
> > > > Hi:
> > > >
> > > >   Looks like that the abort prefetch hapens somewhere else, not in
> > > > the code You've sent. Take a look at the reset vector and the code
> > > > that executes there ( if it is in RAM). It may be corrupt for some
> > > > reason. Anyhow, can You figure out the address of the exeption?
> > > >
> > > > iz
> > >
> > > The exception seems to be at 0x31638:
> > >
> > > void vs_reboot(void)
> > > {
> > >
> > >     ...
> > >
> > >    31638:       ebffbb55        bl      20394 <reset_platform>
> > > }
> > >    3163c:       e91ba800        ldmdb   r11, {r11, sp, pc}
> >
> > Strange. Since the abort prefetch happens here (it happens only beacuse
> > of the ABORT signal asserted) it means that <reset_platform> is no longer
> > in valid memory that can be reached by cpu. What kind of memory mapping
> > do You have? Take a look at the linker xxx.ldi script in the platform/hal
> > directory if they if it's correct for  Your memory layout.
> >
> > iz
>
> RAM is mapped to 0x0 and the size is 0x200000. The function reset_platform
> should be and is in this array (0x20394).
>
> Roland

Now, try to replace the 
	bl	<reset_platform>
with
        mov     r0,#0
        mov     pc,r0           // Jump to reset vector

to see what happens. I dont have any other idea. Do You have any kind of 
memory management on board?

iz


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Re: [ECOS] exception when calling reset_platform

[Roland Caßebohm]

> > > > On Thursday 13 June 2002 18:20, Roland Caßebohm wrote:
> > > > > Hi,
> > > > >
> > > > > my ARM7TDMI (SNDS100 Board) makes an abort prefetch exception when
> > > > > the application calls reset_platform().

Ooops, I think I have to disable the interrupts before trying to reset the 
platform.
I have done this yet and till now the exception don't come anymore.

Roland

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