NAME

monitor − system PROM monitor and command interpreter

SYNOPSIS

Interrupt UNIX bootstrap to activate command interpreter as described below. 

DESCRIPTION

The CPU board of the Sun workstation contains a set of PROMs called the monitor, which control the system during startup.  They normally test the system then search for and attempt to boot UNIX.  However if you interrupt the boot procedure, they enter interactive mode and accept commands interactively.

To enter the interactive mode, power down or reset the system, then interrupt the UNIX bootstrap.  When the message:

autoboot in progress

appears, enter either:

L1 -a (press L1, then a) from the keyboard, or

BREAK (press the break key) from a terminal. 

The monitor displays its prompt:

>

COMMANDS

The list of monitor commands is divided into two sections; miscellaneous commands, and commands to open and examine system memory resources.  These are clustered at the end because they all use the same syntax. 

The miscellaneous commands are:

b[pathname]
Boot.  By itself, b searches for and boots UNIX; when followed by a pathname, it boots the specified program.  b? lists the possible boot devices. 

c[addr]
Continue executing.  With an address, it executes starting there; without an address, it executes starting at the current PC.

g[addr][param]
Start program execution.  Starts executing code at the specified address; the default is the current PC.

k[number]
Reset.  The default is 0 which resets the system without changing memory or the maps; 1 resets the system except for memory, and 2 resets the entire system including memory and the maps.

s[number]
Set or query the address space to be used by subsequent access commands. number represents the function code to be used; no number prints the current function code. 

u[dev][arg]
Change UART assignment.  This command manipulates the on-board UARTs and switches the current input and output device.  It accepts the following devices:

a — SIO-A
b — SIO-B
s — screen
k — keyboard

And the following arguments:

i — input
o — output
# (a number) — UART speed
u addr — Set virtual UART address. 

The commands a, d, e, l, m, o, p, and r open various system resources so that you can examine and change the contents.  These commands all use the following syntax:

c[addr][a...]

where:

cis the command

addris the address (in hex) or the register number

ais a desired action.  A hex number means "write this as data"; any non-hex character means "read this location"

The following paragraphs describe these commands:

a[addr][a...]
Open A-register. n is between 0 and 7, 0 starts at the boundary defined by the command s, and 7 is the stack pointer. 

d[addr][a...]
Open D-register.  n is 0 to 7, with default 0. 

e[addr][a...]
Open word in memory.  Default address is 0 as set by the command s, and odd addresses are rounded down. 

l[addr][a...]
Open longword.  Opens the longword at the address addr; the default is 0 in the address space set by s, and odd addresses are rounded down. 

m[addr][a...]
Open segment map entry which maps virtual address addr in the current context.  Current s command setting determines supervisor or user context. (0-3 = user; 4-7 = supervisor). 

o[addr][a...]
Open byte location.  Opens the byte at the specified location; the default is 0 in the address space specified by s. 

p[addr][a...]
Open page map entry which maps virtual address addr in the current context.  The default is 0.  The choice of context is determined by the current s setting (0-3 = user; 4-7 = supervisor).  Displays the revelant segment map entry with each page map entry in brackets. 

r[addr][a...]
Open miscellaneous registers, as follows:

ssis the supervisor stack pointer

us
is the user stack pointer

sf
is the source function code

df
is the destination function code

vb
is the vector base

sc
is the system context

uc
is the user context

sr
is the status register

pc
is the program counter.

Changes made to these registers (except sc and vc) do not take effect until the next c command. 

Sun Release 2.0  —  Last change: 28 March 1985