debugger

jarcher jarcher at pobox.com
Thu May 15 13:49:28 CEST 2003


A POST (power on self test) card is basically a dumb card that decodes an 
I/O port (80h) and displays the value.  Nothing but the CPU access to the 
ROM and I/O bus (PCI or ISA) has to work to access the card.

         mov     al, CRUMB_1
         out     80h,al

Like I said really down and dirty.  But sometimes that's the only way to 
debug a system.

I snagged a link to some sources from a message posted here a couple of 
days ago.

Jordan

At 10:54 AM 5/15/2003 -0700, Frank wrote:
>I don't mind getting dirty. as a matter of fact i prefer to work
>in the dirt. That's why I'm looking at linuxbios.:-)
>I come from a ppc and mips world where debuuger's are a lot more
>plentiful and cheaper. What is a "POST card"...
>--- jarcher <jarcher at pobox.com> wrote:
> > To add to Ron's message.
> >
> > It varies a lot with your experience and how dirty you want to
> > get.
> >
> > A simple POST card and a lot of creative POST code bread
> > crumbs is the
> > cheap and dirty way to go, until you get the serial port
> > debugger up and
> > running.  But it requires you to be really creative in
> > crawling through the
> > code.  And takes a lot of time.
> >
> > But you can move up the a logic analyzer looking at bus cycles
> > or an ICE
> > (in circuit emulator) looking at CPU activity  These two are
> > expensive
> > (lots of $10K), but you can often rent them.  Setup is usually
> > the time
> > burner here.  But with a LA you can take selective pictures of
> > events
> > chained together in time.  I don't know if SIS has an ICE for
> > their SOC
> > products.
> >
> > Jordan
> >
> > PS: Has anyone done a USB interface low level debugger?  Early
> > BIOS or at
> > least just prior to payload decompress.
> >
> >
> > At 12:00 PM 5/15/2003 -0400, you wrote:
> > >Message: 10
> > >Date: Thu, 15 May 2003 08:50:44 -0700 (PDT)
> > >From: Frank <frannk_m1 at yahoo.com>
> > >Subject: Re: debugger
> > >To: ron minnich <rminnich at lanl.gov>
> > >Cc: linuxbios at clustermatic.org
> > >
> > >sis55x SOC x86 based
> > >--- ron minnich <rminnich at lanl.gov> wrote:
> > > > On Thu, 15 May 2003, Frank wrote:
> > > >
> > > > > Can anyone recommend a debugger for bringing up
> > LinuxBios on
> > > > an
> > > > > x86 system...
> > > >
> > > > what kind of chip? and how much money can you spend?
> > > >
> > > > ron
> >
> > _______________________________________________
> > Linuxbios mailing list
> > Linuxbios at clustermatic.org
> > http://www.clustermatic.org/mailman/listinfo/linuxbios
>
>
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