Boot from UDA50/RA81 on second VAX Unibus

[Pieter Hartel]

The following describes a modification to be made to the BSD 4.1a code
to support a UDA50/RA81 as a boot device on the second Unibus of a
VAX-11/7[58]0

The problem is, that the stand alone driver for the UDA50/RA81 does not
use the correct unit number, as it may be typed by the operator to the boot
command (e.g. ra(8,0)vmunix). Instead the value 0 is assumed, which
of course works fine for the first Unibus.

The routine "udopen" in /sys/stand/uda.c has to be modified to copy
the "io_unit" field of the "io" parameter to the "io_unit" field
of the local "cudbuf" structure.

The code below shows where one extra statement is to be inserted.


udopen(io)
	register struct iob *io;
{
	register struct mscp *mp;
	int i;

	if (udaddr == 0)
		udaddr = (struct udadevice *)ubamem(io->i_unit, udastd[0]);
	if (ud_ubaddr == 0) {
/* HERE>>>> */	cudbuf.i_unit = io->i_unit; /* INSERT THIS LINE HERE<<<< */
		cudbuf.i_ma = (caddr_t)&uda;
		cudbuf.i_cc = sizeof(uda);
		ud_ubaddr = (struct uda *)ubasetup(&cudbuf, 2);
	}

We wish you luck,		Pieter Hartel & Wiet Bouma
				...!mcvax!uva!root

				University of Amsterdam, Comp. Science Dept.