83 lines
3.4 KiB
Groff
83 lines
3.4 KiB
Groff
|
.CD "dis88 \(en disassembler [IBM]"
|
||
|
|
.SX "dis88\fR [\fB\(eno\fR] \fIinfile\fR [\fIoutfile\fR]"
|
||
|
|
.FL "\(eno" "List the object code along with the assembly code"
|
||
|
|
.EX "dis88 a.out >listing" "Disassemble \fIa.out\fR"
|
||
|
|
.EX "dis88 \(eno a.out listing" "Ditto, but with object code"
|
||
|
|
.PP
|
||
|
|
\fIDis88\fR disassembles 8088 object code to the assembly language format
|
||
|
|
used by
|
||
|
|
.MX .
|
||
|
|
It makes full use of
|
||
|
|
symbol table information, supports separate
|
||
|
|
instruction and data space, and generates synthetic labels when needed.
|
||
|
|
It does not support 8087 mnemonics, symbolic data segment references, or
|
||
|
|
the ESC mnemonic.
|
||
|
|
.PP
|
||
|
|
The program is invoked by:
|
||
|
|
.HS
|
||
|
|
.Cx "dis88 [\(eno] infile [outfile]"
|
||
|
|
.HS
|
||
|
|
The \(eno flag causes object code to be listed.
|
||
|
|
If no outfile is given, \fIstdout\fR is used.
|
||
|
|
.PP
|
||
|
|
The text segment of an object file is always padded to an even address.
|
||
|
|
In addition, if the file has split I/D space, the text segment will be padded
|
||
|
|
to a paragraph boundary (i.e., an address divisible by 16). Due to padding, the
|
||
|
|
disassembler may produce a few spurious, but harmless, instructions at the end
|
||
|
|
of the text segment.
|
||
|
|
.PP
|
||
|
|
Because the information to which initialized data refers cannot generally
|
||
|
|
be inferred from context, the data segment is treated literally. Byte values
|
||
|
|
(in hexadecimal) are output, and long stretches of null data are represented by
|
||
|
|
appropriate \fI.zerow\fR pseudo-ops.
|
||
|
|
Disassembly of the bss segment, on the other
|
||
|
|
hand, is quite straightforward, because uninitialized data is all zero by
|
||
|
|
definition.
|
||
|
|
No data is output in the bss segment, but symbolic labels are output
|
||
|
|
as appropriate.
|
||
|
|
.PP
|
||
|
|
The output of operands in symbolic form is complicated somewhat by the
|
||
|
|
existence of assembler symbolic constants and segment override opcodes. Thus,
|
||
|
|
the program's symbol lookup routine attempts to apply a certain amount of
|
||
|
|
intelligence when it is asked to find a symbol. If it cannot match on a symbol
|
||
|
|
of the preferred type, it may output a symbol of some other type, depending on
|
||
|
|
preassigned (and somewhat arbitrary) rankings within each type. Finally, if
|
||
|
|
all else fails, it will output a string containing the address sought as a hex
|
||
|
|
constant. For user convenience, the targets of branches are also output, in
|
||
|
|
comments, as hexadecimal constants.
|
||
|
|
.SS "Error Messages"
|
||
|
|
.PP
|
||
|
|
Various error messages may be generated as a result of problems encountered
|
||
|
|
during the disassembly.
|
||
|
|
They are listed below
|
||
|
|
.HS.
|
||
|
|
.in +3.20i
|
||
|
|
.ta +2.75i +0.2i
|
||
|
|
.ti -2.95i
|
||
|
|
Cannot access input file \(en Input file cannot be opened or read
|
||
|
|
.ti -2.95i
|
||
|
|
Cannot open output file \(en Output file cannot be created
|
||
|
|
.ti -2.95i
|
||
|
|
Input file not in object format \(en Bad magic number
|
||
|
|
.ti -2.95i
|
||
|
|
Not an 8086/8088 object file \(en CPU ID of the file header is incorrect
|
||
|
|
.ti -2.95i
|
||
|
|
Reloc table overflow \(en Relocation table exceeds 1500 entries
|
||
|
|
.ti -2.95i
|
||
|
|
Symbol table overflow \(en Symbol table exceeds 1500 entries
|
||
|
|
.ti -2.95i
|
||
|
|
Lseek error \(en Input file corrupted (should never happen)
|
||
|
|
.ti -2.95i
|
||
|
|
Warning: no symbols \(en Symbol table is missing (use ast)
|
||
|
|
.ti -2.95i
|
||
|
|
Cannot reopen input file \(en Input file was removed during execution
|
||
|
|
.in -3.20i
|
||
|
|
.SS "Author"
|
||
|
|
.PP
|
||
|
|
\fIDis88\fR was written and
|
||
|
|
copyrighted by G. M. Harding and is included here by permission. It may be
|
||
|
|
freely redistributed provided that complete source code, with all copyright
|
||
|
|
notices, accompanies any redistribution. This provision also applies to any
|
||
|
|
modifications you may make. You are urged to comment such changes, giving,
|
||
|
|
as a minimum, your name and complete address.
|