[ECOS] i386 RedBoot serial

Patrick Doyle wpd@delcomsys.com
Thu Feb 7 05:45:00 GMT 2002

We experienced similar problems when we first started trying to use eCos and
tracked it down to something wrong with one of the serial ports.  Basically,
RedBoot displays its output on all COMM channels (which, in the default
configuration is 2 COM ports and the console) and switches to the first COMM
channel from which it receives a character.  We found that, for some reason,
RedBoot was receiving a 0xFF character on COM2, switching to that, and never
talking to COM1 or the console again.  We solved the problem by only
enabling one serial port (which, due to the configration options at that
time, meant COM1).

I always meant to get back to the list on this, and it just fell of the pile
of things to do :-(.  It would be a relatively simple patch modify RedBoot
to switch to the single COMM channel only when it received a "valid"
character (where "valid" needs to be suitably defined, but 0xFF would
probably be right out).

Paul will chime in here if I am misremembering or have left anything out...


> -----Original Message-----
> From: ecos-discuss-owner@sources.redhat.com
> [mailto:ecos-discuss-owner@sources.redhat.com]On Behalf Of Pete Barrie
> Sent: Thursday, February 07, 2002 3:49 AM
> To: McAtee, Kip; 'ecos-discuss@sources.redhat.com'
> Subject: Re: [ECOS] i386 RedBoot serial
> At 17:03 06/02/2002 -1000, McAtee, Kip wrote:
> >Greetings-
> >
> >I've successfully booted from the pre-built i386 RedBoot
> >binary to the RedBoot> prompt, but the keyboard and the
> >COM1 port don't accept input on several PCs.
> >
> >I'm using Hyperterm at 38400,8,N,1,none with a null
> >modem cable. I see the boot messages (June 8, 2001 build)
> >and the Redboot> prompt on both the video and the COM1
> >port. Should I try a different terminal program?
> This is interesting to me. I had redboot fail on several PC's
> but then work on another (older Dell PII 180MHz) machine.
> Failure always takes the same form on these non-working nodes:
> 1.Target PC boots:
> 2.Target PC delivers prompt via serial Port (seen on Hypertyerm on
> my Win 2000 host)
> Then...
>     Target PC does not respond to Hyperterm
>     Target PC local keyboard does not respond
> Have others had this hit/miss experience with target PC's?
> However, the latest advice on this group is to rebuild
> redboot for i386 target PC's rather than use the prebuilt binary.
> I've yet to get time to do this but will report back.
> Maybe solves this issue?
> Pete
> See recent mail from:
> Date: Wed, 6 Feb 2002 19:19:18 -0800 (PST)
> From: michael shiloh <michael@magrittesystems.com>
> To: "McAtee, Kip" <Kip.McAtee@SpirentCom.COM>
> Pete
> >My compliments and appreciation-
> >Kip

More information about the Ecos-discuss mailing list