[E3-hacking] PBL & running arbitrary code

[Ralph Corderoy]

Hi Matt,

> Another possibility (that'll be a bit more convenient than JTAGging it
> each time) would be - if the /WE pin is wired on the board (which I
> suspect it is) - to reprogram the PBL rom in-situ after downloading a
> little JTAG loader.  We could patch PBL to accept code over serial...
> Or if we're going to go this route, just replace it.  So many options!
> ;)

The 64KiB NOR flash has the ability to `blow' the first of its 8KiB
pages so it can never be altered.  See its data sheet.  I doubt this has
been done on the E2 because it would be inconvenient to the
manufacturer.

> (I'm still hoping for some sort of buff. ovf. in PBL so we can keep it
> unmodified - so much safer, easier, less time consuming (in some
> ways).)

Agreed.  Buy Emailer.  Connect EXP port to computer with special cable.
Run program on PC.  Have control of Emailer.  No case opening,
soldering, or knowledge required would be nice.

Cheers,


Ralph.