Is there a standard that defines the syntax and semantics of assembly language? Similarly as language C has ISO standard and language C# has ECMA standard? Is there only one standard, or are there more of them?
I'm asking because I noticed that assembly language code looked different on Windows and Linux environment. I hoped that assembly language is not dependent on OS, that it's only language with some defined standard and via assembler (compiler of assembly language) is translated into machine instructions for particular processor.
thank you for answer
The closest thing to a standard is that the vendor that created the processor/instruction set will have a document describing that language and often that vendor will provide some sort of an assembler (program). Some vendors are more detail and standard oriented than others so you get what you get. Then things like this intel/at&t happen to mess things up. Add to that gnu assembler loves to mess up the assembly language for the chips it supports as well so in general you have chaos.
If there were an assembly language whose use were comparable to C or C++ then you would expect an organization to try to come up with a standard. Part of the problem would still be that with things like the C language there is an interpretation before it hits the hardware, with assembler there is none to very little so a chip vendor is going to make whatever they want to make due to market factors and the standard would have to be dragged along to match the hardware, instead of the other way around where a standard drives the vendors.
The opencore processor might be one that could be standards driven since it is not vendor specific, perhaps it is already.
With assembly assume that each version of each assembler program/software/tool has its own syntax rules within the same instruction set as well as across different instruction sets. (which is actually what you get with C/C++ but that is another topic) either choose your favorite tool and only know it, or try to memorize all the variations across all the tools, or my preference is to try to avoid as many tool specific syntax and nuances, and try to find the middle ground that works or at least has a chance to work or port across tools.