This has been discussed already: https://board.flatassembler.net/topic.php?t=20762

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The FASM DLL outputs code that is in raw binary format, this means that then when running that code, it may not work properly if it's not loaded at the correct address. For example, lets say I made launcher in Windows (using something like C or C++ to write the launcher) that used FASM DLL to assemble code and then run it. There's no guarenty what address in memory the assembled code will be at. Therefore the fasm_Assemble function should in addition to outputting a byte array for the assembled code, it should also output relocation information, so that the launcher program that ran the fasm_Assemble function could then proceed to use this info to perform relocation fixes on the code prior to running the code.

If you don't want to add this feature to the fasm_Assemble function, maybe have the FASM DLL store this relocation info internally after running fasm_Assemble and then make a new function for the calling code to get that relocation info (maybe call it fasm_GetRelocs).

This relocation information would consist of a doubleword value stating the number of relocation entries, followed by the array of relocation entries. Each relocation entry would contain the offset to where the relocation needed to be performed, and the size of the relocation (whether it's 2, 4, or 8 bytes).

Since the launcher program for the assembled code would already know where the assembled code is in memory, it could use this relocation information to fix the absolute addresses that appear in the code.

While a simple ORG statement in the will work if the location the code will be executed from is known before assembling it, in many cases the exact location where the code will be executed from is not known before assembling the code. And leaving out the ORG statement of course is just equivalent to starting the code with an address of 0 (in other words, equivalent to "ORG 0"). So making the code that is generated by the FASM DLL, actually work properly in the launcher program (which is responsible for both assembling and running the code), will require that this launcher program have access to the relocation information.

Is this a feature you intend to add to future versions of the FASM DLL?

You can write position independent code if it is important that it executes from all offsets. Code can also relocate itself if you want it to.

64-bit code is easier to make position independent than 32-bit code. But it can be done in both.

Maybe so, but I think it would expand the usefulness of the FASM DLL if it could output a list of relocations.

Can you use PE format in the FASM DLL? I thought the DLL version exclusively output only raw binary format.

Try it and see what happens.