UA1ZBE Custom Firmware v1.0

Features:
- VFO mode with direct frequency input
- POCSAG decoder (512/1200 baud) with BCH(31,21) correction
- Full-screen Spectrum analyzer
- FM Radio receiver
- RSSI signal indicator overlay
- Custom boot splash (UA1ZBE / POCSAG pager / build date)

Architecture:
- app/mode.c — mode dispatcher (VFO/POCSAG/Spectrum/FM)
- app/boot_splash.c — 2-second boot splash
- app/pocsag/ — POCSAG decoder + BCH correction
- app/display_rssi.c — RSSI indicator
- main.c — entry point with custom init
- syscalls.c — bare-metal _sbrk stub

Build: arm-none-eabi-gcc -Os -flto -Wall -Werror -Wextra
Size: 57.9KB Flash / 3.6KB RAM

Controls:
- 0-9: Direct frequency input (VFO)
- SK2: POCSAG mode
- SK1: Spectrum analyzer
- 0: FM Radio
- EXIT: Return to VFO
- F/*: Toggle 512/1200 baud (in POCSAG)

external/CMSIS_5/CMSIS/RTOS2/RTX/Examples/MemPool/main.c

@@ -0,0 +1,135 @@
+/* -------------------------------------------------------------------------- 
+ * Copyright (c) 2013-2019 ARM Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *      Name:    main.c
+ *      Purpose: RTX example program
+ *
+ *---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+
+#include "RTE_Components.h"
+#include  CMSIS_device_header
+#include "cmsis_os2.h"
+
+void app_main (void *argument);
+void app_msg (void *argument);
+
+typedef struct msg_s {
+  uint8_t cmd;
+  uint8_t len;
+  uint8_t data[8];
+} msg_t;
+
+static osMessageQueueId_t msgQueue;
+static osMemoryPoolId_t memPool;
+
+static const osThreadAttr_t msgAttr = {
+  .stack_size = 400U
+};
+
+/*----------------------------------------------------------------------------
+ * Application main thread
+ *---------------------------------------------------------------------------*/
+
+void app_main (void *argument) {
+  (void)argument;
+
+  osStatus_t status;
+  uint32_t cnt = 0UL;
+  msg_t* msg;
+
+  while (1) {
+    // Allocate memory for the message
+    msg = osMemoryPoolAlloc(memPool, osWaitForever);
+    if (msg == NULL) {
+      printf("app_msg: osMemoryPoolAlloc failed.\n");
+      continue;
+    }
+
+    // Produce a new message and put it to the queue
+    ++cnt;
+    msg->cmd = 1U;
+    msg->len = 4U;
+    *((uint32_t*)(msg->data)) = cnt;
+    status = osMessageQueuePut(msgQueue, &msg, 0U, osWaitForever);
+    if (status != osOK) {
+      printf("app_main: osMessageQueuePut failed.\n");
+    }
+
+    // Defer message creation
+    osDelay(osMessageQueueGetCount(msgQueue)*100U);
+  }
+}
+
+/*----------------------------------------------------------------------------
+ * Application message receiver thread
+ *---------------------------------------------------------------------------*/
+
+void app_msg (void *argument) {
+  (void)argument;
+
+  osStatus_t status;
+  uint32_t cnt;
+  msg_t* msg;
+
+  while (1) {
+    // Defer message processing
+    osDelay(osMessageQueueGetSpace(msgQueue)*100U);
+
+    // Wait forever until a message could be received
+    status = osMessageQueueGet(msgQueue, &msg, NULL, osWaitForever);
+    if (status != osOK) {
+      printf("app_msg: osMessageQueueGet failed.\n");
+    } else {
+      if (msg->len == 4U) {
+        cnt = *((uint32_t*)(msg->data));
+      }
+      printf("app_msg: received [cmd = %d, data = 0x%0X]\n", msg->cmd, cnt);
+      
+      // Free memory of the message
+      status = osMemoryPoolFree(memPool, msg);
+      if (status != osOK) {
+        printf("app_msg: osMemoryPoolFree failed.\n");
+      }
+    }
+  }
+}
+
+/*----------------------------------------------------------------------------
+ * Main entry
+ *---------------------------------------------------------------------------*/
+
+int main (void) {
+
+  // System Initialization
+  SystemCoreClockUpdate();
+
+  osKernelInitialize();                 // Initialize CMSIS-RTOS
+
+  osThreadNew(app_main, NULL, NULL);    // Create application main thread
+  osThreadNew(app_msg, NULL, &msgAttr); // Create message receiver thread
+
+  // Create message queue used to pass pointers to msg_t
+  msgQueue = osMessageQueueNew(10U, sizeof(msg_t*), NULL);
+  
+  // Create memory pool for actual message objects
+  memPool = osMemoryPoolNew(10U, sizeof(msg_t), NULL);
+
+  osKernelStart();                      // Start thread execution
+  for (;;) {}
+}