Zydis  v2.0.3
Zydis Documentation

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Fast and lightweight x86/x86-64 disassembler library.

Features

  • Supports all x86 and x86-64 (AMD64) instructions and extensions
  • Optimized for high performance
  • No dynamic memory allocation ("malloc")
  • Thread-safe by design
  • Very small file-size overhead compared to other common disassembler libraries
  • Complete doxygen documentation
  • Absolutely no dependencies — not even libc
    • Should compile on any platform with a working C99 compiler
    • Tested on Windows, macOS, FreeBSD and Linux, both user and kernel mode

Quick Example

The following example program uses Zydis to disassemble a given memory buffer and prints the output to the console.

#include <stdio.h>
#include <inttypes.h>
#include <Zydis/Zydis.h>
int main()
{
uint8_t data[] =
{
0x51, 0x8D, 0x45, 0xFF, 0x50, 0xFF, 0x75, 0x0C, 0xFF, 0x75,
0x08, 0xFF, 0x15, 0xA0, 0xA5, 0x48, 0x76, 0x85, 0xC0, 0x0F,
0x88, 0xFC, 0xDA, 0x02, 0x00
};
// Initialize decoder context.
ZydisDecoder decoder;
&decoder,
ZYDIS_ADDRESS_WIDTH_64);
// Initialize formatter. Only required when you actually plan to
// do instruction formatting ("disassembling"), like we do here.
ZydisFormatter formatter;
// Loop over the instructions in our buffer.
// The IP is chosen arbitrary here in order to better visualize
// relative addressing.
uint64_t instructionPointer = 0x007FFFFFFF400000;
size_t offset = 0;
size_t length = sizeof(data);
&decoder, data + offset, length - offset,
instructionPointer, &instruction)))
{
// Print current instruction pointer.
printf("%016" PRIX64 " ", instructionPointer);
// Format & print the binary instruction
// structure to human readable format.
char buffer[256];
&formatter, &instruction, buffer, sizeof(buffer));
puts(buffer);
offset += instruction.length;
instructionPointer += instruction.length;
}
}
ZYDIS_EXPORT ZydisStatus ZydisDecoderDecodeBuffer(const ZydisDecoder *decoder, const void *buffer, ZydisUSize bufferLen, ZydisU64 instructionPointer, ZydisDecodedInstruction *instruction)
Decodes the instruction in the given input buffer.
ZYDIS_EXPORT ZydisStatus ZydisDecoderInit(ZydisDecoder *decoder, ZydisMachineMode machineMode, ZydisAddressWidth addressWidth)
Initializes the given ZydisDecoder instance.
ZYDIS_EXPORT ZydisStatus ZydisFormatterInit(ZydisFormatter *formatter, ZydisFormatterStyle style)
Initializes the given ZydisFormatter instance.
@ ZYDIS_FORMATTER_STYLE_INTEL
Generates intel-style disassembly.
Definition: Formatter.h:65
ZYDIS_EXPORT ZydisStatus ZydisFormatterFormatInstruction(const ZydisFormatter *formatter, const ZydisDecodedInstruction *instruction, char *buffer, ZydisUSize bufferLen)
Formats the given instruction and writes it into the output buffer.
@ ZYDIS_MACHINE_MODE_LONG_64
64 bit mode.
Definition: SharedTypes.h:76
#define ZYDIS_SUCCESS(status)
Checks if a zydis operation was successfull.
Definition: Status.h:167
Master include file, including everything else.
Defines the ZydisDecodedInstruction struct.
Definition: DecoderTypes.h:818
ZydisU8 length
The length of the decoded instruction.
Definition: DecoderTypes.h:830
Defines the ZydisDecoder struct.
Definition: Decoder.h:151
Defines the ZydisFormatter struct.
Definition: Formatter.h:578

Sample Output

The above example program generates the following output:

007FFFFFFF400000 push rcx
007FFFFFFF400001 lea eax, [rbp-0x01]
007FFFFFFF400004 push rax
007FFFFFFF400005 push qword ptr [rbp+0x0C]
007FFFFFFF400008 push qword ptr [rbp+0x08]
007FFFFFFF40000B call [0x008000007588A5B1]
007FFFFFFF400011 test eax, eax
007FFFFFFF400013 js 0x007FFFFFFF42DB15

Build

Unix

Zydis builds cleanly on most platforms without any external dependencies. You can use CMake to generate project files for your favorite C99 compiler.

git clone 'https://github.com/zyantific/zydis.git'
cd zydis
mkdir build && cd build
cmake ..
make

Windows

Either use the Visual Studio 2017 project or build Zydis using CMake (video guide).

ZydisInfo tool

ZydisInfo

Bindings

Official bindings exist for a selection of languages:

Inofficial but actively maintained bindings:

Credits

  • Intel (for open-sourcing XED, allowing for automatic comparision of our tables against theirs, improving both)
  • LLVM (for providing pretty solid instruction data as well)
  • Christian Ludloff (http://sandpile.org, insanely helpful)
  • LekoArts (for creating the project logo)
  • Our contributors on GitHub

License

Zydis is licensed under the MIT license.