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digitalmars.D.learn - Hello Assembly!

reply "Taylor Hillegeist" <taylorh140 gmail.com> writes:
So i was playing around with the D inline assembly trying to make 
it say hello world on my windows setup...

void main(){
     asm
     {
         myhello:
         db "HELLO, WORLD$";
         mov EAX , myhello;
         mov AH, 0x09;
         int 0x21;
     }
}


I figure this should do it. but i'm running into problems. 
Anybody know why?
Aug 12 2015
next sibling parent reply Justin Whear <justin economicmodeling.com> writes:
On Wed, 12 Aug 2015 22:10:30 +0000, Taylor Hillegeist wrote:


 I figure this should do it. but i'm running into problems. Anybody know
 why?


Describe "problems"
Aug 12 2015
parent "Taylor Hillegeist" <taylorh140 gmail.com> writes:
On Wednesday, 12 August 2015 at 22:14:58 UTC, Justin Whear wrote:

 On Wed, 12 Aug 2015 22:10:30 +0000, Taylor Hillegeist wrote:


 I figure this should do it. but i'm running into problems. 
 Anybody know why?


 Describe "problems"


object.Error (0): Access Violation
----------------
0x00402028
0x38004023
0x6C0018FF
0x38004023
0xE50018FF
0xA1004022
0x010041E0
0x38000000
0x5C0018FF
0x38000001
0xD00018FF
0xF40100FD
0x780018FD
0x1E0018FF


Thats pretty much it!
Aug 12 2015
prev sibling parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Wednesday, 12 August 2015 at 22:10:32 UTC, Taylor Hillegeist 
wrote:

 So i was playing around with the D inline assembly trying to 
 make it say hello world on my windows setup...


Have you ever written assembly for Windows before? Your code 
looks more like DOS (aside from the EAX, which would be 
overwriten by the AH mov anyway! In DOS, I think it was DX.)

But DOS code won't work here anyway, since it was 16 bit and D 
makes 32 or 64 bit exes.

The way you'd typically do it on Windows is to just call one of 
the win32 api functions, similarly to how you'd do it from C or 
regular D, just calling the functions manually.
Aug 12 2015
next sibling parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Wednesday, 12 August 2015 at 22:18:41 UTC, Adam D. Ruppe wrote:

 The way you'd typically do it on Windows is to just call one of 
 the win32 api functions, similarly to how you'd do it from C or 
 regular D, just calling the functions manually.


Here's an example:

import core.sys.windows.windows; // make the names of C funcs 
available

void main() {
     int written; // just let D handle the local var for us

     asm
     {
         // the goal is:
         // WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), 
myhello.ptr, myhello.length, &written, null);

         // so call GetStdHandle first
         push STD_OUTPUT_HANDLE;
         call GetStdHandle;
         // the return value is now in EAX
         mov EBX, EAX; // save it for later in EBX

         // we push arguments from right to left for the 
WriteConsoleA call..
         push 0; // null
         mov EAX, written; // local vars in D are available too
         push EAX; // &written
         push 13; // length of "HELLO, WORLD\n"
         lea EAX, myhello; // the address of our string
         push EAX; // pointer
         push EBX; // our saved handle from before
         call WriteConsoleA;
         jmp past_hello; // need to jump past the string since it 
isn't actually executable code!
         myhello:
         db "HELLO, WORLD\n";
         past_hello:
         nop;
     }
}




That should run successfully.

Putting the string in a db like that isn't ideal either, you 
should probably just put it in an ordinary D variable too so the 
compiler can place it in the right place.

Then you can also load it. Since D asm complains about the .ptr 
property thinking it means an instruction, I would do something 
like:

string hello = "HELLO, WORLD\n";
auto myhello = hello.ptr;


Then you can just `mov EAX, myhello;` and it will work.
Aug 12 2015
parent "Taylor Hillegeist" <taylorh140 gmail.com> writes:
On Wednesday, 12 August 2015 at 22:32:30 UTC, Adam D. Ruppe wrote:

 On Wednesday, 12 August 2015 at 22:18:41 UTC, Adam D. Ruppe 
 wrote:

 [...]


 Here's an example:

 [...]


Wow, very cool thanks!
Aug 12 2015
prev sibling parent "Taylor Hillegeist" <taylorh140 gmail.com> writes:
On Wednesday, 12 August 2015 at 22:18:41 UTC, Adam D. Ruppe wrote:

 On Wednesday, 12 August 2015 at 22:10:32 UTC, Taylor Hillegeist 
 wrote:

 So i was playing around with the D inline assembly trying to 
 make it say hello world on my windows setup...


 Have you ever written assembly for Windows before? Your code 
 looks more like DOS (aside from the EAX, which would be 
 overwriten by the AH mov anyway! In DOS, I think it was DX.)

 But DOS code won't work here anyway, since it was 16 bit and D 
 makes 32 or 64 bit exes.

 The way you'd typically do it on Windows is to just call one of 
 the win32 api functions, similarly to how you'd do it from C or 
 regular D, just calling the functions manually.


Ahh, It probably is! I was looking for a minimal example. DOS != 
Windows CMD

I was following the example on 
http://web.archive.org/web/20100529113659/http://home.comcast.net/~fbkotler/clueless.html

It is werid working with asm on windows... RISC/asm is much more 
fimilar to me..
Aug 12 2015