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contents of the table " hal_interrupt_handlers" arm7 processor
- From: Bob Brusa <bob dot brusa at gmail dot com>
- To: ecos discuss <ecos-discuss at ecos dot sourceware dot org>
- Date: Sat, 08 Sep 2012 17:56:21 +0200
- Subject: [ECOS] contents of the table " hal_interrupt_handlers" arm7 processor
Hi,
my program generates "spurious interrupts" from time to time. This is
not surprising, because I have several threads that access the data that
are also used by my pwm_isr. And all these data accesses are embedded
between mask/unmask calls as shown below:
cyg_interrupt_mask(CYGNUM_HAL_INTERRUPT_PWMC);
....access here...
cyg_interrupt_unmask(CYGNUM_HAL_INTERRUPT_PWMC);
The hardware-manual tells me that under such conditions, spurious
interrupts are likely to occure (and can thus not be avoided - except
one sacrifices data integrity - which is of course an unacceptable choice)
ECOS has a feature which should handle such "spurious interrupts"
correctly - simply write to eoi and exit - but it does not work
In vectors.S I find the sequence:
---------------------------------------------------------------------
cmp r0,#CYGNUM_HAL_INTERRUPT_NONE // spurious interrupt
bne 10f
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_IGNORE_SPURIOUS
// Acknowledge the interrupt
THUMB_CALL(r1,12,hal_interrupt_acknowledge)
#else
mov r0,v6 // register frame
THUMB_CALL(r1,12,hal_spurious_IRQ)
#endif // CYGIMP_HAL_COMMON_INTERRUPTS_IGNORE_SPURIOUS
b spurious_IRQ
10: ldr r1,.hal_interrupt_data
ldr r1,[r1,v1,lsl #2] // handler data
ldr r2,.hal_interrupt_handlers
ldr v3,[r2,v1,lsl #2] // handler (indexed by vector #)
-----------------------------------------------------------------------
I find, that the jump bne 10f is always executed and subsequently, the
correct handler is fetched from the table hal_interrupt_handlers. But
hellas - when I get my "spurious interrupt" I find that the interrupt
source is correct (10 for pwm), the datapointer however is zero und all
entries in the hal_interrupt_handlers table are filled with the address
of the hal_default_isr.
I would expect the table hal_interrupt_handlers to be initialized during
system startup. But obviously, this assumption is wrong. Which part of
eCOS (dynamically) modifies this table and why??
Thanks for help and advice....Bob
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