[rescue] rescue Digest, Vol 170, Issue 8

[Mike Spooner]

> ----------------------------------------------------------------------
>
> Date: Sun, 15 Jan 2017 12:08:25 +0000
> From: Peter Stokes <peter at ashlyn.co.uk>
> To: The Rescue List <rescue at sunhelp.org>
> Subject: Re: [rescue] IPX boot prom image 525-1177 earlier than 04?
> Message-ID: <851647EE-BB61-40DA-ADE0-1DF949326A2B at ashlyn.co.uk>
> Content-Type: text/plain; charset=us-ascii
>
> Hi Walter
>
> I guess there is a way of mapping the boot rom into memory space and
> running a
> forth loop to print the contents from the ok prompt on a serial console
> such
> as Putty, then copy/paste the results to give a binary hex output, but no
> idea
> of the mapping or the forth loop required, maybe someone here can help?
>
> Peter
> ---------------------------
> Peter Stokes
> Ashlyn Computer Services
> Mbl: 07977 532320
> ---------------------------
>

In fact, the OpenBOOT PROM itself has a "dump" command that will print hex
and ASCII from specifiable memory (virtual address) for a specifiable
length. Although time-consuming, you could use the OBP "map?" command to
probe which virtually- addressed pages are mapped, and use the "dis" and
"+dis" (disassembler) commands to probe for likely-looking PROM
instructions.

On my SS10 using Ross OBP 2.25R, from the "ok" prompt, the PROM image
obviously starts at virtual address f0040000 (and consistently, across
severeal reboot/resets). I would not be surprised if the IPX 2.x PROM is at
the same address. Presumably the length could be intuited/probed using
simlar techniques (or guessed from the capacity of the physical ROM chip
involved).

I'm sure I read of someone once managing to capture an OBP image this way,
over a serial-console, but it was a long time ago, and the (unfortunately
all-too-common-these-days) Web-bit-rot of Sun hardware information seems to
have claimed another victim :-(

-- Mike Spooner