Re: NetBSD and VMEbus RAM

[Michael Thompson <michael.99.thompson%gmail.com@localhost>]

Maybe it really is finding a parity error?

On Thu, Aug 13, 2020 at 4:36 PM Chris Hanson <cmhanson%eschatologist.net@localhost>
wrote:

> On Aug 13, 2020, at 1:32 PM, Michael Thompson <
> michael.99.thompson%gmail.com@localhost> wrote:
> >
> > 
> > The MM-6230 manual says "The user must initialize the memory module to
> allow the parity generator to store ODD parity otherwise the module will
> assert BERR* for any subsequent read cycle."
> >
> > The first time that NetBSD reads an uninitialized location from this RAM
> it will cause a bus error. BetBSD might scan RAM locations to see how much
> RAM is available.
> >
> > You can either write an initialization routine that writes to all memory
> locations on the board before NetBSD touches it, or you can move jumper
> E1-E2 to E2-E3 to prevent the board from causing a BERR*.
>
> Indeed, I read this as well, so before installing the board yesterday I
> set the jumpers to not generate BERR* on parity error and to auto-recover