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/RTOS/RTX/SRC/rt_Time.c

@@ -0,0 +1,84 @@
+/*----------------------------------------------------------------------------
+ *      CMSIS-RTOS  -  RTX
+ *----------------------------------------------------------------------------
+ *      Name:    RT_TIME.C
+ *      Purpose: Delay and interval wait functions
+ *      Rev.:    V4.79
+ *----------------------------------------------------------------------------
+ *
+ * Copyright (c) 1999-2009 KEIL, 2009-2017 ARM Germany GmbH. 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.
+ *---------------------------------------------------------------------------*/
+
+#include "rt_TypeDef.h"
+#include "RTX_Config.h"
+#include "rt_Task.h"
+#include "rt_Time.h"
+
+/*----------------------------------------------------------------------------
+ *      Global Variables
+ *---------------------------------------------------------------------------*/
+
+/* Free running system tick counter */
+U32 os_time;
+
+
+/*----------------------------------------------------------------------------
+ *      Functions
+ *---------------------------------------------------------------------------*/
+
+
+/*--------------------------- rt_time_get -----------------------------------*/
+
+U32 rt_time_get (void) {
+  /* Get system time tick */
+  return (os_time);
+}
+
+
+/*--------------------------- rt_dly_wait -----------------------------------*/
+
+void rt_dly_wait (U16 delay_time) {
+  /* Delay task by "delay_time" */
+  rt_block (delay_time, WAIT_DLY);
+}
+
+
+/*--------------------------- rt_itv_set ------------------------------------*/
+
+void rt_itv_set (U16 interval_time) {
+  /* Set interval length and define start of first interval */
+  os_tsk.run->interval_time = interval_time;
+  os_tsk.run->delta_time = interval_time + (U16)os_time;
+}
+
+
+/*--------------------------- rt_itv_wait -----------------------------------*/
+
+void rt_itv_wait (void) {
+  /* Wait for interval end and define start of next one */
+  U16 delta;
+
+  delta = os_tsk.run->delta_time - (U16)os_time;
+  os_tsk.run->delta_time += os_tsk.run->interval_time;
+  if ((delta & 0x8000U) == 0U) {
+    rt_block (delta, WAIT_ITV);
+  }
+}
+
+/*----------------------------------------------------------------------------
+ * end of file
+ *---------------------------------------------------------------------------*/