Redboot Polling Timers

In my build of Redboot from version eCos 1.0.7 the execution aborts with 
an IU Error when executing __timer_poll. If I remove the call to 
__timer_poll in package tcp.c the initialization proceeds to a RedBoot 
prompt and I can execute commands (ping, help, ip, version, load) at the 
prompt.

One call sequence executes the polling timer with  http_stream_open -> 
__tcp_open -> __tcp_poll -> __timer_poll.  Another starts from 
'net_io_test'. Another one should set the timer with __enet_poll -> 
__ip_handler -> __tcp_handler -> __tcp_send -> __timer_set or similar.  
The debugger shows me '__timer_set' is never called from anywhere so I 
would expect the polling timer to fail as it does.

Can someone suggest why the timers are not being set and what the 
calling sequence should be to set them. I can't yet explain why Redboot 
is functional (to the degree it still is) with the polling timer removed 
as I have done. The hardware abstraction layer is a baseline I have used 
successfully and the hardware has not changed. Platform is SPARC Leon on 
the now vintage GR-XCS-1500 from Pender Electronics.

Thank-you,
Les

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss