[ViewVC] Contents of: cebix/mon/README


        mon, Version 2.2
        A command-driven file monitor

        Copyright (C) 1997-1999 Christian Bauer, Marc Hellwig
        Freely distributable


License
-------

mon is available under the terms of the GNU General Public License. See the
file "COPYING" that is included in the distribution for details.


Overview
--------

"mon" is an interactive command-driven file manipulation tool that is inspired
by the "Amiga Monitor" by Timo Rossi <trossi@jyu.fi>. It has commands and
features similar to a machine code monitor/debugger, but it is not intended
to be used for debugging. It doesn't operate on physical or virtual RAM
locations of a process but rather on a fixed-size (but adjustable) buffer with
adresses starting at 0. Also, there are no commands to trace code, set
breakpoints etc. There are, however, built-in PowerPC, 680x0, 6502 and 8080
disassemblers.


Installation
------------

Please consult the file "INSTALL" for installation instructions.


Usage
-----

mon can be started from the Shell or from the Tracker (BeOS), but command line
history doesn't work when started from the Tracker). If you give no command
line arguments, mon enters interactive mode. Otherwise, all arguments are
interpreted and executed as mon commands. The default buffer size is 1MB.
The mon command prompt looks like this:

  [00000000]->

The number in brackets is the value of "." (the "current address", see the
section on expressions). You can get a short command overview by entering
"h".

Commands that create a longer output can be interrupted with Ctrl-C.

To quit mon, enter the command "x".


Constants, variables and expressions
------------------------------------

The default number base is hexadecimal. Decimal numbers must be prefixed with
"_". Hexadecimal numbers may also be prefixed with "$" for clarity. Numbers
can also be entered as ASCII characters enclosed in single quotes (e.g. 'BAPP'
is the same as $42415050). All numbers are 32-bit values (one word).

With the "set" command, variables can be defined that hold 32-bit integer
values. A variable is referred to by its name. Variable names may be arbitrary
combinations of digits and letters (they may also start with a digit) that
are not also valid hexadecimal numbers. Names are case-sensitive.

mon accepts expressions in all places where you have to specify a number. The
following operators are available and have the same meaning and precedence as
in the C programming language:

  ~   complement
  +   unary plus
  -   unary minus
  *   multiplication
  /   integer division
  %   modulo
  +   addition
  -   subtraction
  <<  shift left
  >>  shift right
  &   bitwise AND
  ^   bitwise exclusive OR
  |   bitwise inclusive OR

Parentheses may be used to change the evaluation order of sub-expressions.

There are two special symbols that can be used in expressions:

  .   represents the "current address" (the value of "." is also displayed in
      the command prompt). What exactly the current address is, depends on the
      command last executed. The display commands set "." to the address after
      the last address displayed, the "hunt" commands sets "." to the address
      of the first found occurence of the search string, etc.
  :   is used by the "apply" ("y") command and holds the value of the byte/
      half-word/word at the current address.

The "modify" (":"), "fill" ("f") and "hunt" ("h") commands require you to
specify a byte string. Byte strings consist of an arbitrary number of byte
values and ASCII strings separated by commas. Examples:

  "string"
  12,34,56,78,9a,bc,de,f0
  "this",0a,"is a string",0a,"with","newlines",_10


The buffer
----------

Those mon commands that operate on "memory" operate on a buffer allocated by
mon whose size is adjustable with the "@" command. The default buffer size is
1MB. The buffer is an array of bytes where each byte has a 32-bit integer
address. Addresses start at 0 and are taken modulo the buffer size (i.e. for
the default 1MB buffer, addresses 0 and 100000 refer to the same byte).

The buffer is the working area of mon where you load files into, manipulate
them, and write files back from. Arbitraty portions of the buffer may be used
as scratch space.


Commands
--------

The following commands are available in mon ('[]' marks a parameter than can be
left out):


  x                        Quit mon

quits mon and returns to the shell.


  h                        Show help text

displays a short overview of commands.


  ??                       Show list of commands

displays a short list of available commands.


  ver                      Show version

shows the version number of mon.


  ? expression             Calculate expression

displays the value of the given expression in hex, decimal, and ASCII
characters. If the value is negative, it is displayed as a signed and unsigned
number.


  @ [size]                 Reallocate buffer

changes the size of the buffer to the given number of bytes while preserving
the contents of the buffer. If the "size" argument is omitted, the current
buffer size is displayed.


  i [start [end]]          ASCII memory dump

displays the buffer contents from address "start" to address "end" as ASCII
characters. Entering "i" without arguments is equivalent to "i .". The value
of "." is set to the address after the last address displayed.


  m [start [end]]          Hex/ASCII memory dump

displays the buffer contents from address "start" to address "end" as hex
words and ASCII characters. Entering "m" without arguments is equivalent to
"m .". The value of "." is set to the address after the last address displayed.


  d [start [end]]          Disassemble PowerPC code

disassembles the buffer contents from address "start" to address "end".
Entering "d" without arguments is equivalent to "d .". The value of "." is
set to the address after the last address displayed.


  d65 [start [end]]          Disassemble 6502 code

disassembles the buffer contents from address "start" to address "end".
Entering "d65" without arguments is equivalent to "d65 .". The value of
"." is set to the address after the last address displayed.


  d68 [start [end]]          Disassemble 680x0 code

disassembles the buffer contents from address "start" to address "end".
Entering "d68" without arguments is equivalent to "d68 .". The value of
"." is set to the address after the last address displayed.


  d80 [start [end]]          Disassemble 8080 code

disassembles the buffer contents from address "start" to address "end".
Entering "d80" without arguments is equivalent to "d80 .". The value of
"." is set to the address after the last address displayed.


  d86 [start [end]]          Disassemble 80x86 code (very incomplete)

disassembles the buffer contents from address "start" to address "end".
Entering "d86" without arguments is equivalent to "d86 .". The value of
"." is set to the address after the last address displayed.


  : start string           Modify memory

puts the specified byte string at the address "start" into the buffer. The
value of "." is set to the address after the last address modified.


  f start end string       Fill memory

fill the buffer in the range from "start" to (and including) "end" with the
given byte string.


  y[b|h|w] start end expr  Apply expression to memory

works like the "fill" ("f") command, but it doesn't fill with a byte string
but with the value of an expression that is re-evaluated for each buffer
location to be filled. The command comes in three flavors: "y"/"yb" works on
bytes (8-bit), "yh" on half-words (16-bit) and "yw" on words (32-bit). The
value of "." is the current address to be modified,  the value of ":" holds
the contents of this address before modification.

Examples:
  yw 0 fff :<<8    shifts all words in the address range 0..fff to the left
                   by 8 bits (you can use this to convert bitmap data from
                   ARGB to RGBA format, for example)
  y 0 1234 ~:      inverts all bytes in the address range 0..1234
  yh 2 ff 20000/.  creates a table of the fractional parts of the reciprocals
                   of 1..7f


  t start end dest         Transfer memory

transfers the buffer contents from "start" to (and including) "end" to "dest".
Source and destination may overlap.


  c start end dest         Compare memory

compares the buffer contents in the range from "start" to (and including)
"end" with the contents at "dest". The addresses of all different bytes and
the total number of differences (decimal) are printed.


  h start end string       Search for byte string

searches for the given byte string in the buffer starting at "start" up to
(and including) "end". The addresses and the total number of occurrences are
displayed. The value of "." is set to the address of the first occurrence. 


  \ "command"              Execute shell command

executes the given shell command which must be enclosed in quotes.


  ls [args]                List directory contents

works as the shell command "ls".


  rm [args]                Remove file(s)

works as the shell command "rm".


  cp [args]                Copy file(s)

works as the shell command "cp".


  mv [args]                Move file(s)

works as the shell command "mv".


  cd directory             Change current directory

works as the shell command "cd". The name of the directory doesn't have to be
enclosed in quotes.


  o ["file"]               Redirect output

When a file name is specified, all following output is redirected to this
file. The file name must be enclosed in quotation marks even if it contains
no spaces. Entering "o" without parameters closes the file and directs the
output into the terminal window again.


  [ start "file"           Load data from file

loads the contents of the specified file into the buffer starting from address
"start". The file name must be enclosed in quotation marks even if it contains
no spaces. The value of "." is set to the address after the last address
affected by the load.


  ] start size "file"      Save data to file

writes "size" number of bytes of the buffer from "start" to the specified file.
The file name must be enclosed in quotation marks even if it contains no spaces.


  set [var[=value]]        Set/clear/show variables

If no arguments are given, all currently defined variables are displayed.
Otherwise, the value of "var" is set to the specified value. If "=value"
is omitted, the variable "var" is cleared.


  cv                       Clear all variables

clears all currently defined variables.


rmon
----

When mon is started as "rmon", it enters "real mode". That is, all memory
related functions no longer operate on the buffer but on "real" (virtual)
memory. Unless you are writing Mac emulators, this is probably of not much
use. :-)


Examples
--------

Here are some simple examples for what is possible with mon.

Join "file1" and "file2" to "file3":

  [ 0 "file1"
  [ . "file2"
  ] 0 . "file3"

Remove the first 24 bytes (e.g. an unneeded header) of a file:

  [ 0 "file"
  ] 18 .-18 "file"

Load the mon executable and search for PowerPC "nop" commands:

  [ 0 "mon"
  h 0 . 60,00,00,00

Create a modified version of mon so that the prompt has " $" instead of "->":

  [ 0 "mon"
  set size=.
  h 0 . "->"
  : . " $"
  ] 0 size "mon1"

Convert a binary file which contains 16-bit numbers in little-endian format
to big-endian format (or vice-versa):

  [ 0 "file"
  yh 0 .-1 :>>8|:<<8  
  ] 0 . "file"

Load a BeBox boot ROM image and start disassembling the system reset handler:

  [ 0 "bootnub.image"
  d 100


History
-------

Please consult the file "ChangeLog" for the release history.


Christian Bauer
<Christian.Bauer@uni-mainz.de>

Marc Hellwig
<Marc.Hellwig@uni-mainz.de>
Revision:	1.2
Committed:	1999-10-04T19:40:36Z (25 years, 1 month ago) by cebix
Branch:	MAIN
Changes since 1.1:	+11 -30 lines
Log Message:	- added some doc files
#	Content
1
2	mon, Version 2.2
3	A command-driven file monitor
4
5	Copyright (C) 1997-1999 Christian Bauer, Marc Hellwig
6	Freely distributable
7
8
9	License
10	-------
11
12	mon is available under the terms of the GNU General Public License. See the
13	file "COPYING" that is included in the distribution for details.
14
15
16	Overview
17	--------
18
19	"mon" is an interactive command-driven file manipulation tool that is inspired
20	by the "Amiga Monitor" by Timo Rossi <trossi@jyu.fi>. It has commands and
21	features similar to a machine code monitor/debugger, but it is not intended
22	to be used for debugging. It doesn't operate on physical or virtual RAM
23	locations of a process but rather on a fixed-size (but adjustable) buffer with
24	adresses starting at 0. Also, there are no commands to trace code, set
25	breakpoints etc. There are, however, built-in PowerPC, 680x0, 6502 and 8080
26	disassemblers.
27
28
29	Installation
30	------------
31
32	Please consult the file "INSTALL" for installation instructions.
33
34
35	Usage
36	-----
37
38	mon can be started from the Shell or from the Tracker (BeOS), but command line
39	history doesn't work when started from the Tracker). If you give no command
40	line arguments, mon enters interactive mode. Otherwise, all arguments are
41	interpreted and executed as mon commands. The default buffer size is 1MB.
42	The mon command prompt looks like this:
43
44	[00000000]->
45
46	The number in brackets is the value of "." (the "current address", see the
47	section on expressions). You can get a short command overview by entering
48	"h".
49
50	Commands that create a longer output can be interrupted with Ctrl-C.
51
52	To quit mon, enter the command "x".
53
54
55	Constants, variables and expressions
56	------------------------------------
57
58	The default number base is hexadecimal. Decimal numbers must be prefixed with
59	"_". Hexadecimal numbers may also be prefixed with "$" for clarity. Numbers
60	can also be entered as ASCII characters enclosed in single quotes (e.g. 'BAPP'
61	is the same as $42415050). All numbers are 32-bit values (one word).
62
63	With the "set" command, variables can be defined that hold 32-bit integer
64	values. A variable is referred to by its name. Variable names may be arbitrary
65	combinations of digits and letters (they may also start with a digit) that
66	are not also valid hexadecimal numbers. Names are case-sensitive.
67
68	mon accepts expressions in all places where you have to specify a number. The
69	following operators are available and have the same meaning and precedence as
70	in the C programming language:
71
72	~ complement
73	+ unary plus
74	- unary minus
75	* multiplication
76	/ integer division
77	% modulo
78	+ addition
79	- subtraction
80	<< shift left
81	>> shift right
82	& bitwise AND
83	^ bitwise exclusive OR
84	\| bitwise inclusive OR
85
86	Parentheses may be used to change the evaluation order of sub-expressions.
87
88	There are two special symbols that can be used in expressions:
89
90	. represents the "current address" (the value of "." is also displayed in
91	the command prompt). What exactly the current address is, depends on the
92	command last executed. The display commands set "." to the address after
93	the last address displayed, the "hunt" commands sets "." to the address
94	of the first found occurence of the search string, etc.
95	: is used by the "apply" ("y") command and holds the value of the byte/
96	half-word/word at the current address.
97
98	The "modify" (":"), "fill" ("f") and "hunt" ("h") commands require you to
99	specify a byte string. Byte strings consist of an arbitrary number of byte
100	values and ASCII strings separated by commas. Examples:
101
102	"string"
103	12,34,56,78,9a,bc,de,f0
104	"this",0a,"is a string",0a,"with","newlines",_10
105
106
107	The buffer
108	----------
109
110	Those mon commands that operate on "memory" operate on a buffer allocated by
111	mon whose size is adjustable with the "@" command. The default buffer size is
112	1MB. The buffer is an array of bytes where each byte has a 32-bit integer
113	address. Addresses start at 0 and are taken modulo the buffer size (i.e. for
114	the default 1MB buffer, addresses 0 and 100000 refer to the same byte).
115
116	The buffer is the working area of mon where you load files into, manipulate
117	them, and write files back from. Arbitraty portions of the buffer may be used
118	as scratch space.
119
120
121	Commands
122	--------
123
124	The following commands are available in mon ('[]' marks a parameter than can be
125	left out):
126
127
128	x Quit mon
129
130	quits mon and returns to the shell.
131
132
133	h Show help text
134
135	displays a short overview of commands.
136
137
138	?? Show list of commands
139
140	displays a short list of available commands.
141
142
143	ver Show version
144
145	shows the version number of mon.
146
147
148	? expression Calculate expression
149
150	displays the value of the given expression in hex, decimal, and ASCII
151	characters. If the value is negative, it is displayed as a signed and unsigned
152	number.
153
154
155	@ [size] Reallocate buffer
156
157	changes the size of the buffer to the given number of bytes while preserving
158	the contents of the buffer. If the "size" argument is omitted, the current
159	buffer size is displayed.
160
161
162	i [start [end]] ASCII memory dump
163
164	displays the buffer contents from address "start" to address "end" as ASCII
165	characters. Entering "i" without arguments is equivalent to "i .". The value
166	of "." is set to the address after the last address displayed.
167
168
169	m [start [end]] Hex/ASCII memory dump
170
171	displays the buffer contents from address "start" to address "end" as hex
172	words and ASCII characters. Entering "m" without arguments is equivalent to
173	"m .". The value of "." is set to the address after the last address displayed.
174
175
176	d [start [end]] Disassemble PowerPC code
177
178	disassembles the buffer contents from address "start" to address "end".
179	Entering "d" without arguments is equivalent to "d .". The value of "." is
180	set to the address after the last address displayed.
181
182
183	d65 [start [end]] Disassemble 6502 code
184
185	disassembles the buffer contents from address "start" to address "end".
186	Entering "d65" without arguments is equivalent to "d65 .". The value of
187	"." is set to the address after the last address displayed.
188
189
190	d68 [start [end]] Disassemble 680x0 code
191
192	disassembles the buffer contents from address "start" to address "end".
193	Entering "d68" without arguments is equivalent to "d68 .". The value of
194	"." is set to the address after the last address displayed.
195
196
197	d80 [start [end]] Disassemble 8080 code
198
199	disassembles the buffer contents from address "start" to address "end".
200	Entering "d80" without arguments is equivalent to "d80 .". The value of
201	"." is set to the address after the last address displayed.
202
203
204	d86 [start [end]] Disassemble 80x86 code (very incomplete)
205
206	disassembles the buffer contents from address "start" to address "end".
207	Entering "d86" without arguments is equivalent to "d86 .". The value of
208	"." is set to the address after the last address displayed.
209
210
211	: start string Modify memory
212
213	puts the specified byte string at the address "start" into the buffer. The
214	value of "." is set to the address after the last address modified.
215
216
217	f start end string Fill memory
218
219	fill the buffer in the range from "start" to (and including) "end" with the
220	given byte string.
221
222
223	y[b\|h\|w] start end expr Apply expression to memory
224
225	works like the "fill" ("f") command, but it doesn't fill with a byte string
226	but with the value of an expression that is re-evaluated for each buffer
227	location to be filled. The command comes in three flavors: "y"/"yb" works on
228	bytes (8-bit), "yh" on half-words (16-bit) and "yw" on words (32-bit). The
229	value of "." is the current address to be modified, the value of ":" holds
230	the contents of this address before modification.
231
232	Examples:
233	yw 0 fff :<<8 shifts all words in the address range 0..fff to the left
234	by 8 bits (you can use this to convert bitmap data from
235	ARGB to RGBA format, for example)
236	y 0 1234 ~: inverts all bytes in the address range 0..1234
237	yh 2 ff 20000/. creates a table of the fractional parts of the reciprocals
238	of 1..7f
239
240
241	t start end dest Transfer memory
242
243	transfers the buffer contents from "start" to (and including) "end" to "dest".
244	Source and destination may overlap.
245
246
247	c start end dest Compare memory
248
249	compares the buffer contents in the range from "start" to (and including)
250	"end" with the contents at "dest". The addresses of all different bytes and
251	the total number of differences (decimal) are printed.
252
253
254	h start end string Search for byte string
255
256	searches for the given byte string in the buffer starting at "start" up to
257	(and including) "end". The addresses and the total number of occurrences are
258	displayed. The value of "." is set to the address of the first occurrence.
259
260
261	\ "command" Execute shell command
262
263	executes the given shell command which must be enclosed in quotes.
264
265
266	ls [args] List directory contents
267
268	works as the shell command "ls".
269
270
271	rm [args] Remove file(s)
272
273	works as the shell command "rm".
274
275
276	cp [args] Copy file(s)
277
278	works as the shell command "cp".
279
280
281	mv [args] Move file(s)
282
283	works as the shell command "mv".
284
285
286	cd directory Change current directory
287
288	works as the shell command "cd". The name of the directory doesn't have to be
289	enclosed in quotes.
290
291
292	o ["file"] Redirect output
293
294	When a file name is specified, all following output is redirected to this
295	file. The file name must be enclosed in quotation marks even if it contains
296	no spaces. Entering "o" without parameters closes the file and directs the
297	output into the terminal window again.
298
299
300	[ start "file" Load data from file
301
302	loads the contents of the specified file into the buffer starting from address
303	"start". The file name must be enclosed in quotation marks even if it contains
304	no spaces. The value of "." is set to the address after the last address
305	affected by the load.
306
307
308	] start size "file" Save data to file
309
310	writes "size" number of bytes of the buffer from "start" to the specified file.
311	The file name must be enclosed in quotation marks even if it contains no spaces.
312
313
314	set [var[=value]] Set/clear/show variables
315
316	If no arguments are given, all currently defined variables are displayed.
317	Otherwise, the value of "var" is set to the specified value. If "=value"
318	is omitted, the variable "var" is cleared.
319
320
321	cv Clear all variables
322
323	clears all currently defined variables.
324
325
326	rmon
327	----
328
329	When mon is started as "rmon", it enters "real mode". That is, all memory
330	related functions no longer operate on the buffer but on "real" (virtual)
331	memory. Unless you are writing Mac emulators, this is probably of not much
332	use. :-)
333
334
335	Examples
336	--------
337
338	Here are some simple examples for what is possible with mon.
339
340	Join "file1" and "file2" to "file3":
341
342	[ 0 "file1"
343	[ . "file2"
344	] 0 . "file3"
345
346	Remove the first 24 bytes (e.g. an unneeded header) of a file:
347
348	[ 0 "file"
349	] 18 .-18 "file"
350
351	Load the mon executable and search for PowerPC "nop" commands:
352
353	[ 0 "mon"
354	h 0 . 60,00,00,00
355
356	Create a modified version of mon so that the prompt has " $" instead of "->":
357
358	[ 0 "mon"
359	set size=.
360	h 0 . "->"
361	: . " $"
362	] 0 size "mon1"
363
364	Convert a binary file which contains 16-bit numbers in little-endian format
365	to big-endian format (or vice-versa):
366
367	[ 0 "file"
368	yh 0 .-1 :>>8\|:<<8
369	] 0 . "file"
370
371	Load a BeBox boot ROM image and start disassembling the system reset handler:
372
373	[ 0 "bootnub.image"
374	d 100
375
376
377	History
378	-------
379
380	Please consult the file "ChangeLog" for the release history.
381
382
383	Christian Bauer
384	<Christian.Bauer@uni-mainz.de>
385
386	Marc Hellwig
387	<Marc.Hellwig@uni-mainz.de>