Section: User Commands (1)
Updated: The Netwide Assembler Project
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ndisasm - the Netwide Disassembler, an 80x86 binary file disassembler
command generates a disassembly listing of the binary file
and directs it to stdout.
to exit immediately, after giving a summary of its invocation
to exit immediately, after displaying its version number.
- -o origin
Specifies the notional load address for the file. This option causes
to get the addresses it lists down the left hand margin, and the
target addresses of PC-relative jumps and calls, right.
- -s sync-point
Manually specifies a synchronisation address, such that
will not output any machine instruction which encompasses bytes on
both sides of the address. Hence the instruction which
at that address will be correctly disassembled.
- -e hdrlen
Specifies a number of bytes to discard from the beginning of the
file before starting disassembly. This does not count towards the
calculation of the disassembly offset: the first
instruction will be shown starting at the given load address.
- -k offset,length
bytes, starting from disassembly offset
should be skipped over without generating any output. The skipped
bytes still count towards the calculation of the disassembly offset.
- -a or -i
Enables automatic (or intelligent) sync mode, in which
will attempt to guess where synchronisation should be performed, by
means of examining the target addresses of the relative jumps and
calls it disassembles.
- -b bits
Specifies either 16-bit or 32-bit mode. The default is 16-bit mode.
Specifies 32-bit mode, more compactly than using `-b 32'.
- -p vendor
Prefers instructions as defined by
in case of a conflict. Known
The default is
only disassembles binary files: it has no understanding of the
header information present in object or executable files. If you
want to disassemble an object file, you should probably be using
Auto-sync mode won't necessarily cure all your synchronisation
problems: a sync marker can only be placed automatically if a jump
or call instruction is found to refer to it
actually disassembles that part of the code. Also, if spurious jumps
or calls result from disassembling non-machine-code data, sync
markers may get placed in strange places. Feel free to turn
auto-sync off and go back to doing it manually if necessary.
can only keep track of 8192 sync markers internally at once: this is
to do with portability, since DOS machines don't take kindly to more
than 64K being allocated at a time.
- SEE ALSO
linux.jgfs.net manual pages