Instructions for using Network Layer

[ReinhardKeil]

Create a README.md in https://github.com/Arm-Examples/SDS-Examples/tree/main/SDS_Interface/Network
that explains:

• how is this layer configured (it uses MDK-Middleware Network)
• how the SDSIO Server is started (configuration for Windows Host system)

Once we have this we need configuration for MacOS and Linux Host systems.

[furbanc]

Instructions added

[ReinhardKeil]

I was not successful with Network communication using Alif DevKit. Suggest the following improvements:

---

1. Inform user to configure IP address when SDSIO_SOCKET_SERVER_IP is 0.0.0.0

As 0.0.0.0 cannot be used as IPv4 address for connection, I suggest to output in this case:

"SDSIO_SOCKET_SERVER_IP not configured; value should be SDSIO-Server socket IPv4 address."

This would make it more obvious that a user setting is required.

---

2. Output the IP address obtained

For example:
"SDSIO-Client IP address: 192.168.2.128"

---

3. Output the configured IP address

This massage would make it clearer to which address the connection attempt happens:

"Connecting to 'sdsio-server socket' on 192.168.2.125:5050"

---

In my case the application seems to hang in `socket_startup.c":

int32_t socket_startup (void) {
  uint32_t addr;

  netInitialize();

  do {
   osDelay(500U);                                           // why is there a need to wait before calling GetOption?
   netIF_GetOption(NET_IF_CLASS_ETH | 0,
                   netIF_OptionIP4_Address,
                   (uint8_t *)&addr, sizeof (addr));
  } while (addr == 0U);                                 // this will hang forever when addr is always 0.

  return 0;
}
```

[furbanc]

Socket startup updated with additional status output. Added server configuration check for address 0.0.0.0 in sds control.

Commit 00bdbcb7