m68kdis.1

m68k系列反汇编的C语言源码,供学习编译原理的同学使用。实用！

.TH M68KDIS 1 "November 15, 1994"
.SH NAME
m68kdis \- disassemble Motorola 68000 family object code
.SH SYNOPSIS
.LP
m68kdis
\fB[\fP\-\fIddd\fP\fB]\fP
\fB[\fP\-a\ \fIfile\fP\fB]\fP
\fB[\fP\-all[c]\fB]\fP
\fB[\fP\-b\ \fIfile\fP\fB]\fP
\fB[\fP\-bad\fB]\fP
\fB[\fP\-f\ \fIfile\fP\fB]\fP
\fB[\fP\-fdigits\ \fIdigits\fP\fB]\fP
\fB[\fP\-i\ \fIfile\fP\fB]\fP
\fB[\fP\-isp\fB]\fP
\fB[\fP\-j\ \fIfile\fP\fB]\fP
\fB[\fP\-l\fB]\fP
\fB[\fP\-lft\fB]\fP
\fB[\fP\-n\ \fIfile\fP\fB]\fP
\fB[\fP\-ns\ \fIfile\fP\fB]\fP
\fB[\fP\-o\ \fIfile\fP\fB]\fP
\fB[\fP\-odd\fB]\fP
\fB[\fP\-pc\ \fIinitialpc\fP\fB]\fP
\fB[\fP\-s\ \fIlength\fP\fB]\fP
\fB[\fP\-slenp\ \fIlength\fP\fB]\fP
\fB[\fP\-sp\fB]\fP
\fIfile...\fP
.SH DESCRIPTION
.LP
.I m68kdis
is a disassembler for the Motorola 68000 family of cpu chips.
The disassembler attempts to discern between the instruction
and data portions of an object code file.
.LP
.I m68kdis
produces output files much like
.BR cc (1).
When the \fB\-o\fP option is not used, file arguments that end in \.o
have output filenames with \.s substituted for \.o; otherwise, \.s
is simply appended.
.LP
The output consists of five columns:
.IP \(bu
program counter in hexadecimal
.IP \(bu
file contents with each byte displayed as two characters in hexadecimal
.IP \(bu
label (if any)
.IP \(bu
instruction name
.IP \(bu
operands (if any)
.SH OPTIONS
.LP
.IP "\fI\-ddd\fP"
Specifies the chip and coprocessors.
Valid values for
.I ddd
are currently \fI000\fP, \fI008\fP, \fI010\fP, \fI020\fP,
\fI030\fP, \fI851\fP, \fI881\fP, and \fI882\fP.
This option may be repeated as appropriate.
The default is \fI000\fP with no coprocessors.
.IP "\-a\ \fIfile\fP"
Specifies that
.I file
contains lines of the form ``\fIaXXX\ instruction\-string\fP'' which
specify acceptable A-line opcodes.
.I XXX
is in hexadecimal.
.IP \-all[c]
Specifies that only one pass should be made,
outputting the instruction (if any) at each word boundary.
If the
.I c
is included, \fB\-i\fP, \fB\-j\fP, \fB\-n\fP and \fB\-ns\fP options
are also processed,
and another pass is made to ensure consistency between instructions.
.IP "\-b\ \fIfile\fP"
Specifies that
.I file
contains program counter values which are taken as
locations in data to be output on a new line.
The values should be one to a line, and of a form acceptable to
.BR strtoul ()
with base equal to 0.
.IP \-bad
Specifies that lines should be printed to standard error that specify
which data caused a potential instruction to be made invalid.
.IP "\-f\ \fIfile\fP"
Specifies that
.I file
contains lines of the form ``\fIfXXX\ instruction\-string\fP'' which
specify acceptable F-line opcodes.
.I XXX
is in hexadecimal.
.IP "\-fdigits\ \fIdigits\fP"
Specifies that mantissas of floating-point constants should be printed with
.I digits
significant digits.
The minimum value of
.I digits
is 2; the default is 6.
.IP "\-i\ \fIfile\fP"
Specifies that
.I file
contains program counter values which are, if possible, to be taken as
locations of valid instructions.
The values should be one to a line, and of a form acceptable to
.BR strtoul ()
with base equal to 0.
.IP \-isp
Specifies that the determination of a printing character should be
done by the local system's
.BR isprint ().
By default, only ASCII characters (0x20 to 0x7e inclusive) are considered
printing characters.
.IP "\-j\ \fIfile\fP"
Specifies that
.I file
contains A-line and F-line opcodes which are unconditional jumps and
therefore do not need to be followed by a valid instruction.
The values should be one to a line, and of a form acceptable to
.BR strtoul ()
with base equal to 0.
.IP \-l
Specifies that output should be in lower-case.
(Exception: Label references retain an upper-case ``L''.)
.IP \-lft
Specifies that instructions that ``fall through'' to a LINK instruction
should be considered valid.
By default, these instructions are considered invalid.
.IP "\-n\ \fIfile\fP"
Specifies that
.I file
contains program counter values which are to be taken as
locations of data.
The values should be one to a line, and of a form acceptable to
.BR strtoul ()
with base equal to 0.
.IP "\-ns\ \fIfile\fP"
Specifies that
.I file
contains program counter values which are to be taken as
locations at which instructions do not begin.
The words at these locations may, however, be extension words of instructions.
The values should be one to a line, and of a form acceptable to
.BR strtoul ()
with base equal to 0.
.IP "\-o\ \fIfile\fP"
Specifies the output file.
Only one file to be disassembled may be given when this option is used.
.IP \-odd
Specifies that instructions may begin at odd offsets.
This can be useful when code to be disassembled is not stripped out of
an object file.
In particular, this option is often needed when disassembling
an intact Macintosh resource fork.
.IP "\-pc\ \fIinitialpc\fP"
Specifies that
.I initialpc
be taken as the program counter value for the start of the object code.
The default is 0.
.IP "\-s\ \fIlength\fP"
Specifies that data contain at least
.I length
consecutive printing characters to be output as a string.
The minimum value for
.I length
is 2; the default is 5.
.IP "\-slenp\ \fIlength\fP"
Specifies that strings should print out no more than 
.I length
characters per output line.
The minimum value for
.I length
is 10; the default is 30.
.IP \-sp
Specifies that register A7 should be output as SP, except in MOVEM instructions.
.SH NOTES
.LP
The output is based on Motorola syntax.
.LP
Immediate values are sometimes also output in hexadecimal after an
intervening
'if t \fC!\fP.
'if n !.
.LP
The following procedure is used to filter out the data from the instructions:
.IP \(bu
An initial pass is made determining at which file offsets potential
instructions exist and the sizes of those instructions including operands.
.IP \(bu
File offsets specified by the user as being data are processed.
.IP \(bu
File offsets specified by the user as not starting instructions are processed.
.IP \(bu
File offsets specified by the user as being instructions are processed.
.IP \(bu
Potential instructions which reference data as instructions
are changed to data.
(This step is repeated after each of the remaining steps.)
.IP \(bu
LINK instructions which are referenced by BSR and JSR instructions are
accepted as final instructions.
(A final instruction is one that is included in the final output.)
.IP \(bu
Remaining LINK instructions are accepted as final instructions.
.IP \(bu
Branching and jumping instructions that reference final instructions
and are not potential extension words of floating-point instructions
are accepted as final instructions.
.IP \(bu
Remaining branching and jumping that are not extension words of
potential floating-point instructions
and returning instructions are accepted as final instructions.
.IP \(bu
Overlapping instructions are selected by minimizing the amount of data.
.SH BUGS
.LP
Since
.I m68kdis
uses the imperfect procedure given in the \fB\s-2NOTES\s+2\fP,
errors may result in the instruction/data determination.
When problems are suspected, the \fB\-bad\fP\fIX\fP option can be used
to determine why instructions get interpreted as data.
You can then use the \fB\-i\fP, \fB\-ns\fP, and \fB\-n\fP options,
as appropriate.
.LP
The character set used in the object file may be neither ASCII
nor that used by the local system.
.LP
Two unusual conditions checked for should be mentioned.
Sometimes the decision to designate an instruction as a final instruction
is later contradicted and the instruction is changed to data.
In general, the instruction causing the contradiction should be
regarded as data via the \fB\-ns\fP option.
Also, sometimes it is reported that there is an ``overlap'' at a
certain offset.
This is because
.I m68kdis
is unsure if the best selection of two possible instructions
which overlap each other was made.
A quick inspection of the output at this offset should clear this up.
Messages for these conditions are printed to standard error.
.SH "SEE ALSO
.IP 1.
Motorola: \fIM68000 8/16/32 Bit Microprocessors:
Programmer's Reference Manual\fP\&, 5th ed\., Prentice-Hall,
Englewood Cliffs, NJ, 1986.
.IP 2.
Motorola: \fIM68030: Enhanced 32-Bit Microprocessor
User's Manual\fP\&, 2nd ed\., Prentice-Hall,
Englewood Cliffs, NJ, 1989.
.IP 3.
Motorola: \fIM68851: Paged Memory Management Unit
User's Manual\fP\&, 2nd ed\., Prentice-Hall,
Englewood Cliffs, NJ, 1989.
.IP 4.
Motorola: \fIM68881/MC68882: Floating-Point Coprocessor
User's Manual\fP\&, 2nd ed\., Prentice-Hall,
Englewood Cliffs, NJ, 1989.
.SH AUTHOR
.LP
.nf
Christopher G. Phillips
[e-mail]