Fix missing CONFIG_64BIT kernel for older kernel
On older kernel < 5.X sigcontext.h defines this flag `#ifdef CONFIG_64BIT` which prevents building on some platforms.
@@ -432,6 +432,11 @@ endif()
string(COMPARE EQUAL "${CMAKE_HOST_SYSTEM_PROCESSOR}" "i686" _x86)
string(COMPARE EQUAL "${CMAKE_HOST_SYSTEM_PROCESSOR}" "x86_64" _x86_64)
+string(COMPARE EQUAL "${CMAKE_HOST_SYSTEM_PROCESSOR}" "aarch64" _aarch64)
+
+if(_x86_64 OR _aarch64)
+ add_definitions(-DCONFIG_64BIT)
+endif()
if(NOT _x86 AND NOT _x86_64)
install(TARGETS ${BOX64}
