The smallest executable

[Vortex]

Creating small executables is interesting also while working with HLLs.

[Gunther]

Creating small executables is interesting also while working with HLLs.

But the EXE files generated by compilers are not so small.

Gunther

[jj2007]

But the EXE files generated by compilers are not so small.

Erol is a genius, he can produce a 1.5k C executable. The problem with such tiny programs is that a) they can't fill a hard drive sector (4k) and b) they don't do anything useful (but wait until Alex logs in :lol:)

[frktons]

I've done some refinement to the code, and got rid of about
20 instructions, sparing some 50-60 bytes, but still not sufficient
to reduce the size to 2K. It's actually fixed at 2,5K.

I've seen that there is a lot of space for size reduction, so the 2K
goal is quite feasible.

Attached the shrinked version 0.4.

Frank

[frktons]

In order to get rid of the .data section altogether, I need
to transform this line of .data:

Code Select Expand


ConTitle  db " -----------   **  Extended ASCII chart displayable characters  **  ----------", 0


in a line of LOCAL to put inside the PROC that uses it.

I have no clue how to do it. Any help is welcome.

[dedndave]

it doesn't need to be local
what you want is to put it in the code section

if you did want it to be local, you could push it onto the stack in reverse order - very clumsy

[frktons]

it doesn't need to be local
what you want is to put it in the code section

if you did want it to be local, you could push it onto the stack in reverse order - very clumsy

I want to put it in the .code section, but I don't know how.
How I define it, where I put these bytes?

[dedndave]

stick it any place you like, really - someplace where it won't be executed   :P

Code Select Expand

DisplaySequence ENDP

ConTitle  db " -----------   **  Extended ASCII chart displayable characters  **  ----------", 0

; -------------------------------------------------------------------------
; Writes the Screen Title with enhanced color attribute White on Magenta
;--------------------------------------------------------------------------

WriteScreenTitle PROC

as a matter of practice, i try to define things earlier in the source than where i use them
that isn't always practical

[frktons]

stick it any place you like, really - someplace where it won't be executed   :P

Code Select Expand

DisplaySequence ENDP

ConTitle  db " -----------   **  Extended ASCII chart displayable characters  **  ----------", 0

; -------------------------------------------------------------------------
; Writes the Screen Title with enhanced color attribute White on Magenta
;--------------------------------------------------------------------------

WriteScreenTitle PROC

as a matter of practice, i try to define things earlier in the source than where i use them
that isn't always practical

In this way the .data section is not created? Because this is my goal here.

[dedndave]

if there is nothing left in the .DATA section, don't use .DATA and it won't be created

[frktons]

if there is nothing left in the .DATA section, don't use .DATA and it won't be created

OK, good.  :t My .data section is empty and deleted from the program,
but nothing changes in the size of the prog. 2,560 bytes  ::)

[frktons]

The prog without the .data section attached. Anyone can see where I can
save some other bytes?

[jj2007]

DisplayFmt PROC szFmtName:DWORD
LOCAL rc:SMALL_RECT
  movlps xmm0, windowSize        ; make a copy
  movlps rc, xmm0
  INVOKE WriteConsoleOutput, wHnd, szFmtName, DWORD PTR bufferSize,
  DWORD PTR startPoint, addr rc                ; offset windowSize crashes the app
  ret
DisplayFmt ENDP

[sinsi]

If they don't change then put them in .code
Of course, some APIs will expect to write to it...

offset windowSize crashes the app

lpWriteRegion [in, out]
A pointer to a SMALL_RECT structure. On input, the structure members specify the upper-left and lower-right coordinates of the console screen buffer rectangle to write to. On output, the structure members specify the actual rectangle that was used.

[jj2007]

On output,

Indeed, see movlps above. Strange that it apparently did not crash on Frank's machine.