Re: VAX RPB (Restart Parameter Block)

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

> The Netbsd bootloader is faking an RPB in autoconf.c: [...]

> ...and I think that the behavior with the reboot has something todo
> with that "bootregs".

Quite possibly.

> so I've looked at the ../../include/rpb.h file:

>  * Look at "VAX/VMS Internals and Data Structures" around page 907
>  * to get more info about RPB.

You probably can also check your hardware's doc - I think you have the
hardware manual, right? - for how your particular hardware reacts to
various settings in the RPB.

> Or what is that rpb_rstflag meaning, I read somewhere in the rtVAX
> manual that a restart should be prevented when the booted Os is
> broken (for debugging purposes).

The KA630 manual describes a "restart in progress" flag which the OS is
presumably expected to change once it's far enough up that it should be
considered successfully booted.  It's not in the RPB, though:

    The  console  keeps  a  "Restart in progress" flag in CPMBX bit 3,
    which  it  uses  to  avoid  repeated attempts to restart a failing
    operating  system. An additional "Restart in progress" flag may be
    maintained by software in the RPB.

However, this affects attempts to restart the OS, not behaviour on
HALT.  Behaviour on HALT is controlled by a hardware pin and
CPMBX<1:0>.

Of course, how similar this is to your rtVAX is the real question.  The
KA630 manual has a section that's all about what the hardware does on
the various halt conditions (section 4.4.4, page 4-9); it doesn't go
into details about what the ROM code does (that's earlier - 3.3, page
3-7).  Does your hardware manual have something similar perhaps?

/~\ The ASCII                             Mouse
\ / Ribbon Campaign
 X  Against HTML                mouse%rodents-montreal.org@localhost
/ \ Email!           7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B