User`s guide
The instructions contained within these indirect command files causes the console subsystem to perform
the following sequence of events (Figure 3-1):
• Initialize the
CPU
to
a known state
and
load
the address
of
the first 64K bytes
of
good
memory
plus 200, which was located
by
the console program, into
the
stack
pointer
(SP
which is
GPR
E).
• Load parameters into the general registers
RO
through R5. These parameters inform the
primary bootstrap program what to load (either the operating system or diagnostic supervisor),
what device to load from and how to load it. The parameters
that
can be loaded into the general
registers are shown in Table 3-1.
•
Examine
the
stack pointer
(SP)
for
the
address
of
the first 64K bytes
of
good memory.
This
address is
placed
in a console RAM location
to
be
used when
the
@ symbol replaces this
address.
• Load the primary bootstrap program VMB.EXE into memory starting
at
the address
in
the SP,
then start the program.
•
Start
processing instructions
in
VMB.EXE. VMB.EXE takes control and loads the secondary
bootstrap
program (either
SYSBOOT.EXE
for cold
starting
the operating system or
DIAGBOOT.EXE for cold starting the diagnostic supervisor) into memory and starts it
running.
Register
RO
Rl
R2
R3
Table 3-1 Parameters Loaded into the General Registers
at
BOOT
Parameters
<07:00>
1 (hex)
2 (hex)
3 (hex)
17
(hex)
32 (hex)
64 (hex)
<15:08>
<31:16>
<31:04>
<03:00>
<31:18>
<17:00>
Description
Cold start device type code
RK06/7
RLOI/2
IDe
(R80, RL02)
UDA-50 (RA80,
RA81,
RA60)
HSC
on CI
TU58
Reserved for future expansion
Device class dependent
(RPB$WROUBVEC).
UNIBUS-optional vector address; 0
implies use the default vector.
Cold start device bus adapter address
MBZ
TR
number
of
adapter
UNIBUS
bootstrap device code
MBZ
UNIBUS
address
of
cold start device's
CSR
Cold start device controller unit number
3-5