The attached file contains the sources of fdisax64.dll and an example.

The fdisax64.dll implements the Disax function to disassemble one 64-bit x86 instruction.

The Disax function takes 3 parameters :
- rcx: address of the instruction
- rdx: address of a buffer to receive the source of up to 128 characters
- r8: virtual code address
The Disax function returns in rax the nb. of bytes of the decoded instruction.

Disax uses source files from fdbg0025 by fasm users "Feryno" and "tthsqe"
with the following additions and modifications:

- cbw, cwde, cdqe, rdpid, retf, retfw, retfq
- MPX : bndmk, bndcl, bndcu, bndcn, bndmov, bndldx, bndstx
- MPX : 'BND' prefix
- discard duplicate rex prefix bytes

I wrote "SoS" in the comment of the source code that I added or modified.
The example allows you to experiment with x86 instructions.

Brought to you by fasm forum user seppe.

Hi seppe,

nice work! I've downloaded Disax.zip for trialling it on Linux.
It needed only a couple of form changes in disax.asm:
+ lines 2-3: format elf64, and comment out win64a.inc (not included)
+ lines 7-8: make it "section '.text' executable align 16" and "public Disax" (instead of entry)
+ line 33: make it "section '.data' writeable align 16"
+ lines 69-71: remove those last 3 lines

By that, it compiles nicely to a linkable object module (disax.o). I then introduced it to my rrqforth interpreter[1] for experimenting. Initially just wrapped it the "disax" word plus a dedicated buffer (named "axbuf"). We'll see where it goes

regards,
Ralph.

[1] https://board.flatassembler.net/topic.php?t=21955