[ECOS] context for creating interrupts on edb7312

["Aaron Case" <aaron dot case at dynazign dot com>]

Hello,

My question pertains to the context for which an interrupt would be created
and attached.

The Massa text shows an example where an interrupt is created, attached, and
unmasked in cyg_user_start(), see code listing 3.2. Yet 3 pages later, see
Item list 3.7, it gives thread(and not init as in the code listing) as the
only viable context for creating a interrupt(via cyg_interrupt_create).
This seems to be in conflict.

Intuitively, creation of interrupts would be in cyg_user_start, init
context, like the code listing example BUT, I was never able to get this to
work. I have however been able to get work in the thread context, which
agrees with the item list but seems counter intuitive.

The eCos reference manual confirms my intuition by stating the following in
the valid context section of the ref manual...

"In a typical configuration interrupt handlers are created and attached
during system initialization, and never detached or deleted. However it is
possible to perform these operations at thread level, if desired..."

I, however, have not be able to get interrupts to work in the init context,
only in the thread context.

------Is creating interrupts within the init context possible?-------

I am using the EDB7312 processor with the arm720t core.

I would prefer to locate all interrupt creation and configuration in
cyg_user_start, the init context, but have had little success in doing so.

I would also like to add, Im not criticizing the online docs, they appear
correct, just a bit generic(so as to apply to all platforms, I assume).

Aaron Case
Firmware Engineer
Dynazign, Inc.
Charlotte, NC


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