NSIS ANTI EMULATOR - nsis

Question

I'm trying to make a anti emulator
allocating a big memory region and force the kernel to commit the pages to physical ram by filling the memory with values because the emulator can't allocate too much memory
But I don't know how to fill the memory with values of that region
this is what I made so far
System::Call "kernel32::LocalAlloc(i 0, i 143978374) p .r0" ; allocate 143 978 374 bytes and write pointer in $0
;I need to fill the memory with values here
System::Call "kernel32::LocalFree(p r0)"

Answer 1

If you call LocalAlloc with the LMEM_ZEROINIT flag Windows might write to the buffer for you. Technically speaking, this might be a implementation detail and in theory a future system could support such a feature in hardware. Your emulation thing, whatever that is, might ignore it as well.
You can write to memory with the system plug-in struct syntax:
!define PAGESIZE 4096
!define BLOBSIZE 143978374
!include Util.nsh
!ifndef IntPtrOp ; NSIS 2 compatibility
!define IntPtrOp IntOp
!endif
!ifndef IntPtrCmpU
!define IntCmpU
!endif
System::Alloc ${BLOBSIZE} ; This calls GlobalAlloc(GPTR, ...)
Pop $0
${IntPtrCmpU} $0 0 done "" "" ; Failure to allocate memory?
StrCpy $1 $0 ; Start
${IntPtrOp} $2 $1 + ${BLOBSIZE} ; End
loop:
System::Call '*$1(&i1 42)' ; Set the first byte in the page to 42
${IntPtrOp} $1 $1 + ${PAGESIZE}
${IntPtrCmpU} $1 $2 "" loop ""
System::Free $0
done:
The System plug-in is not super fast so a large memory block will take a while to fill.