low level masm

[plaguez]

Hello,

I want to learn assembler, so I am more interested in doing everything myself. Surely this is possible? What I want to do first is print numbers and string to the screen. So I can see what my newbie programs are doing. So do I have to include all those files and libraries? is the windows.inc necessary?

thanks.

[qWord]

So do I have to include all those files and libraries? is the windows.inc necessary?

no, but it makes things easier.
Especially as beginner you should use the HLL stuff, which comes with MASM and the MASM32 package (IMO).

[hutch--]

plaguez,

Yo can do it that way if you take long enough and know enough about it. First you create your own include files and libraries so that you can interface with the operating system, then you write your own runtime library so you can doo all those hacky things like write to the screen, file IO and so on. Should be about 5 years work from scratch.  :P

[dedndave]

i think i can understand his point
using things that are pre-made can hide underlying information
for example, if you use the "print" macro, you have no idea what happens and really don't learn anything
may as well be writing in BASIC   :P

but, there is a better approach to learning
in the example i mentioned, use the print macro
but, do a little research into how the macro is written
it calls a function - look that function up and understand it
that function uses a few API calls - look them up
then, use the macro to be productive and learn something else

you can write things for windows without using windows.inc
but - you will be learning the same things over and over - and not move very fast, either   :'(
i can write a simple trivial without windows.inc, but you don't want to write only trivials
i can't imagine writing anything useful without the inc files

[sjums]

Here's the print macro

Code Select Expand

print MACRO arg1:REQ,varname:VARARG      ;; display zero terminated string
        IFNDEF __UNICODE__
          invoke StdOut,expand_prefix(reparg(arg1))
        ELSE
          invoke StdOutW,expand_prefix(reparg(arg1))
        ENDIF
      IFNB <varname>
        IFNDEF __UNICODE__
          invoke StdOut,chr$(varname)
        ELSE
          invoke StdOutW,chr$(varname)
        ENDIF
      ENDIF
    ENDM

It invokes StdOut, which is this

Code Select Expand

; #########################################################################

    .386
    .model flat, stdcall
    option casemap :none   ; case sensitive

    include \masm32\include\windows.inc
    include \masm32\include\kernel32.inc

    StrLen PROTO :DWORD

    .code

; #########################################################################

StdOut proc lpszText:DWORD

    LOCAL hOutPut  :DWORD
    LOCAL bWritten :DWORD
    LOCAL sl       :DWORD

    invoke GetStdHandle,STD_OUTPUT_HANDLE
    mov hOutPut, eax

    invoke StrLen,lpszText
    mov sl, eax

    invoke WriteFile,hOutPut,lpszText,sl,ADDR bWritten,NULL

    mov eax, bWritten
    ret

StdOut endp

; #########################################################################

end

Which invokes WriteFile.. That's windows API To be found Here


If you download the MASM32 Installer, and unpacks the .zip, you can then again unpack the .exe witch contains the source for the diffrent macros  :)

[dedndave]

it also uses GetStdHandle
so, for those API functions, use MSDN...

GetStdHandle
http://msdn.microsoft.com/en-us/library/windows/desktop/ms683231%28v=vs.85%29.aspx

WriteFile
http://msdn.microsoft.com/en-us/library/windows/desktop/aa365747%28v=vs.85%29.aspx

at the bottom of those pages is a list of links for further reading
for example, at the bottom of the GetStdHandle page is a link...

Console Handles
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682075%28v=vs.85%29.aspx