format PE GUI 4.0 at 0x400000

include 'win32a.inc'

section '.text' code readable executable
		; Sekcie s kodom pravo na zapis vacsinou z bezpcnostnych dovodov nemaju nastavene. Preto je potrebne nasledujucim volanim API nastavit
		; V nasledujucom pouziti ziadame nastavit prava len na 1 byte, OS windows dokaze nastavit prava iba po strankach - 0x1000 bytov.
		; preto mozme prepisovat aj dalsie byty.
		invoke VirtualProtect,JNE_INSTRUCTION, 1, PAGE_EXECUTE_READWRITE,old_protect
		cmp eax,0
		jz EXIT
		
		;SMC - toto prepise instrukciu JNE na JE
		mov byte [JNE_INSTRUCTION],0x74
		;xor byte [JNE_INSTRUCTION],0x01   ;JNE = "0x75";  0x75 xor 0x01 =  0x74
	
		;CMP: if (4=5) then MessageBox(...)
		mov eax, 4
		mov ebx, 5
		cmp eax, ebx
		
	JNE_INSTRUCTION:
		jne EXIT_1   ; v momente, ked sa zacne vykonavat tato instrukcia, tak uz bude predchadzajucim "mov"-om prepisana
		invoke MessageBoxA, 0, message_text,message_caption, MB_OK+MB_ICONINFORMATION
	EXIT_1:
		; obnova prav - toto uz aplikacii nepomoze, je to tu len pre uplnost
		invoke VirtualProtect,JNE_INSTRUCTION, 1, [old_protect],old_protect
	EXIT:
		ret
	
section '.bss' readable writeable
	old_protect   dd ?

section '.data' readable
	message_text	db 'Zazrak!',0
	message_caption db 'OK',0

section '.idata' import data readable writeable
	library \
		kernel32,'KERNEL32.DLL',\
		user32	,'USER32.DLL'
	import kernel32,\
		VirtualProtect	   ,'VirtualProtect'
	import user32,\
		MessageBoxA	  ,'MessageBoxA'

;section '.reloc' fixups data readable discardable