[ECOS] interrupt handlers for the ARM SA1110

[Warren Jasper <wjasper@tx.ncsu.edu>]

I have a few comments and a suggestion.

Per Gary Thomas's suggestion, I have added  some hooks to the file
/hal/arm/sa11x0/var/current/src/sa11x0_misc.c so that I could extend the

hal_interrupt_handle table to include 32 extra interrupts from my DSP.
The file
is attached.   Changes are like:

/* macro for board specific IRQ handler */
#ifdef HAL_EXTENDED_IRQ_HANDLER
      HAL_EXTENDED_IRQ_HANDLER(index);
 #endif

Please consider wrapping these changes into the main distribution.
That way, hooks will be
available for other variants of the sa11x0  to incorporate extra
interrupts.

The user needs to replace
hal/arm/sa11x0/var/current/include/hal_var_ints.h with
a modified version:
hal/arm/sa11x0/variant_board_hal/include/platform_hal_ints.h

and in the cdl for the variant, include the lines:

    define_proc {
        puts $::cdl_header \
       "#define CYGBLD_HAL_PLF_INTS_H <cyg/hal/hal_platform_ints.h>"
    }

Unfortunately, doing this may or may not work.  There is a somewhat
cryptic comment
(I guess cryptic comments are better than no comments ???) in
/hal/arm/arch/current/src/vectors.S  near the end:

//
-------------------------------------------------------------------------

// Interrupt vector tables.
// These tables contain the isr, data and object pointers used to
deliver
// interrupts to user code.

// Despite appearances, their sizes are not #defines, but .equ symbols
// generated by magic without proper dependencies in arm.inc
// Recompiling will not DTRT without manual intervention.

        .data

init_flag:
        .balign 4
        .long   0

 .extern hal_default_isr

 .globl  hal_interrupt_handlers
hal_interrupt_handlers:
        .rept   CYGNUM_HAL_ISR_COUNT
        .long   hal_default_isr
        .endr

Once  CYGNUM_HAL_ISR_COUNT is redefined, it sure would be nice to know
exactly how to
 increase the size of the table, and to know up front that the following
wont' work:

ecosconfig tree
make clean
make

I ended up disassembling the code and counting the size of
hal_interrupt_handlers before I
felt confident that that size of the table (which is kind of important)
was what I thought it was.

Warren