Add FreeRTOS port with blocking bsd socket API

README.md

@@ -74,6 +74,19 @@ The `-I wtcp0` flag pins the test to the injected interface and `-c5`
 generates five echo requests.  Successful replies confirm the ICMP
 datagram socket support end-to-end through the tap device.
 
+## FreeRTOS Port
+
+wolfIP now includes a dedicated FreeRTOS wrapper port at:
+
+- `src/port/freeRTOS/bsd_socket.c`
+- `src/port/freeRTOS/bsd_socket.h`
+
+This port follows the same model as the POSIX wrapper:
+
+- One background task loops on `wolfIP_poll()`
+- Socket wrappers serialize stack access with a mutex
+- Blocking operations wait on callback-driven wakeups (instead of busy polling)
+
 ## Copyright and License
 
 wolfIP is licensed under the GPLv3 license. See the LICENSE file for details.

src/port/freeRTOS/README.md

@@ -0,0 +1,117 @@
+# wolfIP FreeRTOS Port
+
+This directory provides a FreeRTOS integration layer for wolfIP with:
+
+- A dedicated polling task that runs `wolfIP_poll()` in a loop.
+- POSIX-style blocking socket calls (`socket`, `bind`, `listen`, `accept`, `recv`, `send`, `close`, ...).
+- Event-driven wakeups from wolfIP callbacks, synchronized with FreeRTOS mutexes/semaphores.
+
+## Files
+
+- `bsd_socket.c`
+  FreeRTOS socket wrapper implementation and poll task.
+- `bsd_socket.h`
+  Public API for initialization and socket calls.
+
+## Design
+
+1. A global lock protects wolfIP core/socket operations.
+2. A poll thread/task calls `wolfIP_poll()` periodically.
+3. Blocking socket operations:
+   - Try the underlying non-blocking wolfIP socket call.
+   - If `-WOLFIP_EAGAIN`, register a callback and block on a FreeRTOS semaphore.
+   - Wake when the required event is observed, then retry.
+
+This gives application code standard blocking socket behavior while wolfIP remains polled internally.
+
+## Poll Task Example
+
+The integration creates a dedicated task similar to:
+
+```c
+static void wolfip_poll_task(void *arg)
+{
+    struct wolfIP *ipstack = (struct wolfIP *)arg;
+
+    for (;;) {
+        uint32_t next_ms;
+        TickType_t delay_ticks;
+        uint64_t now_ms = (uint64_t)xTaskGetTickCount() * (uint64_t)portTICK_PERIOD_MS;
+
+        xSemaphoreTake(g_lock, portMAX_DELAY);
+        next_ms = (uint32_t)wolfIP_poll(ipstack, now_ms);
+        xSemaphoreGive(g_lock);
+
+        if (next_ms < WOLFIP_FREERTOS_POLL_MIN_MS) {
+            next_ms = WOLFIP_FREERTOS_POLL_MIN_MS;
+        }
+        if (next_ms > WOLFIP_FREERTOS_POLL_MAX_MS) {
+            next_ms = WOLFIP_FREERTOS_POLL_MAX_MS;
+        }
+
+        delay_ticks = pdMS_TO_TICKS(next_ms);
+        if (delay_ticks == 0) {
+            delay_ticks = 1;
+        }
+        vTaskDelay(delay_ticks);
+    }
+}
+```
+
+## Integration Steps
+
+1. Include headers:
+
+```c
+#include "wolfip.h"
+#include "bsd_socket.h"
+```
+
+2. Initialize wolfIP core and low-level device first (your Ethernet/driver setup).
+3. Start the FreeRTOS socket layer:
+
+```c
+int ret = wolfip_freertos_socket_init(ipstack, poll_task_priority, poll_task_stack_words);
+```
+
+4. Use POSIX-style socket API:
+
+```c
+int fd = socket(AF_INET, SOCK_STREAM, 0);
+bind(fd, ...);
+listen(fd, ...);
+int cfd = accept(fd, NULL, NULL);
+int n = recv(cfd, buf, sizeof(buf), 0);
+send(cfd, buf, n, 0);
+close(cfd);
+close(fd);
+```
+
+## API
+
+- `int wolfip_freertos_socket_init(struct wolfIP *ipstack, UBaseType_t poll_task_priority, uint16_t poll_task_stack_words);`
+- `int socket_last_error(void);`
+- Socket calls:
+  - `socket`, `bind`, `listen`, `accept`, `connect`, `close`
+  - `send`, `sendto`, `recv`, `recvfrom`
+  - `setsockopt`, `getsockopt`, `getsockname`, `getpeername`
+
+## Configuration Knobs
+
+Defined in `bsd_socket.c`:
+
+- `WOLFIP_FREERTOS_BSD_MAX_FDS` (default: `16`)
+- `WOLFIP_FREERTOS_POLL_MIN_MS` (default: `5`)
+- `WOLFIP_FREERTOS_POLL_MAX_MS` (default: `20`)
+
+Override via compiler flags, for example:
+
+```make
+CFLAGS += -DWOLFIP_FREERTOS_BSD_MAX_FDS=32
+```
+
+## Notes
+
+- `wolfip_freertos_socket_init()` should be called once after wolfIP/device init and before socket usage.
+- File descriptors returned by this layer are wrapper FDs, not raw wolfIP internal FDs.
+- The wrapper is intended for task context (not ISR context).