cmake_minimum_required(VERSION 3.16)

set(testdata "${CMAKE_CURRENT_LIST_DIR}/testdata.bin")

file(REMOVE "${testdata}")

find_program(dd dd)
execute_process(COMMAND ${dd} if=/dev/zero "of=${testdata}" bs=1M count=2048)
file(APPEND "${testdata}" "1")

file(READ "${testdata}" data OFFSET 2147483648)
if(NOT "${data}" STREQUAL "1")
    message(FATAL_ERROR "data=${data}")
else()
    message("data=${data}")
endif()