1NDISASM(1) The Netwide Assembler Project NDISASM(1)
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6 ndisasm - the Netwide Disassembler, an 80x86 binary file disassembler
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9 ndisasm [ -o origin ] [ -s sync-point [...]] [ -a | -i ] [ -b bits ] [
10 -u ] [ -e hdrlen ] [ -p vendor ] [ -k offset,length [...]] infile
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13 The ndisasm command generates a disassembly listing of the binary file
14 infile and directs it to stdout.
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17 -h
18 Causes ndisasm to exit immediately, after giving a summary of its
19 invocation options.
20 -r|-v
22 Causes ndisasm to exit immediately, after displaying its version
23 number.
24 -o origin
26 Specifies the notional load address for the file. This option
27 causes ndisasm to get the addresses it lists down the left hand
28 margin, and the target addresses of PC-relative jumps and calls,
29 right.
30 -s sync-point
32 Manually specifies a synchronisation address, such that ndisasm
33 will not output any machine instruction which encompasses bytes on
34 both sides of the address. Hence the instruction which starts at
35 that address will be correctly disassembled.
36 -e hdrlen
38 Specifies a number of bytes to discard from the beginning of the
39 file before starting disassembly. This does not count towards the
40 calculation of the disassembly offset: the first disassembled
41 instruction will be shown starting at the given load address.
42 -k offset,length
44 Specifies that length bytes, starting from disassembly offset
45 offset, should be skipped over without generating any output. The
46 skipped bytes still count towards the calculation of the
47 disassembly offset.
48 -a|-i
50 Enables automatic (or intelligent) sync mode, in which ndisasm will
51 attempt to guess where synchronisation should be performed, by
52 means of examining the target addresses of the relative jumps and
53 calls it disassembles.
54 -b bits
56 Specifies 16-, 32- or 64-bit mode. The default is 16-bit mode.
57 -u
59 Specifies 32-bit mode, more compactly than using ‘-b 32’.
60 -p vendor
62 Prefers instructions as defined by vendor in case of a conflict.
63 Known vendor names include intel, amd, cyrix, and idt. The default
64 is intel.
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67 ndisasm only disassembles binary files: it has no understanding of the
68 header information present in object or executable files. If you want
69 to disassemble an object file, you should probably be using objdump(1).
70 Auto-sync mode won’t necessarily cure all your synchronisation
72 problems: a sync marker can only be placed automatically if a jump or
73 call instruction is found to refer to it before ndisasm actually
74 disassembles that part of the code. Also, if spurious jumps or calls
75 result from disassembling non-machine-code data, sync markers may get
76 placed in strange places. Feel free to turn auto-sync off and go back
77 to doing it manually if necessary.
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80 objdump(1)
81NASM 12/21/2022 NDISASM(1)