RE: [ECOS] RedBoot serial rx interrupts

[Gary Thomas <gthomas@cambridge.redhat.com>]

On 12-Jan-2001 Grant Edwards wrote:
> 
> I've got RedBoot running fine without network support.  It's
> using polled serial I/O: the individual serial Rx interrupts
> are unmasked but the global interrupt mask is set.  
> 
> [Why are interrupts being unmasked when polled I/O is being
> used?]
> 

It should not.  Where are you seeing this [which file/line]?

> When I add network support, the global interrupt mask is
> cleared; cyg_hal_plf_serial_isr then consumes all of input
> data.  RedBoot is still calling cyg_hal_plf_serial_getc() to
> try to read input, but it never sees any because it's all being
> consumed by the interrupt routine.
> 
> Can anybody point me to something that explains RedBoot's use
> of interrupts?
> 

RedBoot does not use interrupts.

> Is the network stack interrupt driven?
> 

RedBoot's stack does not.  eCos' does of course.

> Why does including network support clear the global interrupt
> mask bit?
> 

It does not - or should not - for RedBoot.

> When is serial I/O interrupt driven?
> 

Only when you use the serial I/O functions (serial_write, etc).

Are you sure about all of these questions?  RedBoot absolutely _never_
touches interrupts.  The only time interrupts are used is by eCos
applications.