.386
.model flat, stdcall
option casemap :none

include masm32includewindows.inc
include masm32includekernel32.inc
include masm32includeuser32.inc

includelib masm32libkernel32.lib
includelib masm32libuser32.lib

.data

FileIn    db 'input.txt',0     ; file to read
FileOut   db 'output.txt',0    ; file to write

.data?

hFile       dd ?
FileSize    dd ?
hMem        dd ?
BytesRead   dd ?

.code
start:

    invoke  CreateFile,
        ADDR FileIn,
        GENERIC_READ,
        0,
        0,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        0

    mov hFile, eax

    invoke GetFileSize,
        eax,
        0

    mov FileSize, eax
    inc eax

    invoke VirtualAlloc,
        0,
        eax,
        MEM_COMMIT OR MEM_RESERVE,
        PAGE_READONLY

    mov eax, hMem

    invoke ReadFile,
        hFile,
        hMem,
        FileSize,
        ADDR BytesRead,
        0

    invoke  CloseHandle,
        hFile