When reviewing src/bacnet/datalink/bsc/bsc-conf.h, I see the following:

#if !defined(BACDL_BSC)
#define BSC_CONF_TX_PRE 0
#else
#ifndef bsd
#define bsd 1
#endif
#ifndef linux
#define linux 2
#endif
#ifndef win32
#define win32 3
#endif
#if BACNET_PORT == bsd || BACNET_PORT == linux || BACNET_PORT == win32
#include <libwebsockets.h>
#define BSC_CONF_TX_PRE LWS_PRE
#else
#define BSC_CONF_TX_PRE 0
#endif
#endif

My target platform is a small embedded device running FreeRTOS + lwIP (on an MCU).
Although lwIP is “BSD-like,” the device does not really fit into bsd, linux, or win32.

That raises a few questions:

1. In this case, BSC_CONF_TX_PRE will remain 0 and libwebsockets is not used.
   Does this mean that BACnet/SC node devices are expected to implement their own WebSocket layer (for direct connection mode, both server + client), instead of relying on libwebsockets?

2. Is the intention that, in embedded environments, developers should implement WebSocket (RFC 6455 framing and handshake) locally — probably just a few source files — to fit the platform constraints?

3. In other words, is the websocket.h interface in src/bacnet/datalink/ meant as a guide or abstraction layer, so that each integrator can provide their own WebSocket implementation that matches their platform?

OR Just, Do I need to select bsd ? and port libwebsocket ?

I’d like clarification on whether this interpretation is correct.