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/Device/_Template_Flash/FlashDev.c

@@ -0,0 +1,45 @@
+/**************************************************************************//**
+ * @file     FlashDev.c
+ * @brief    Flash Device Description for New Device Flash
+ * @version  V1.0.0
+ * @date     10. January 2018
+ ******************************************************************************/
+/*
+ * Copyright (c) 2010-2018 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.
+ */
+ 
+#include "FlashOS.h"        // FlashOS Structures
+
+
+struct FlashDevice const FlashDevice  =  {
+   FLASH_DRV_VERS,             // Driver Version, do not modify!
+   "New Device 256kB Flash",   // Device Name 
+   ONCHIP,                     // Device Type
+   0x00000000,                 // Device Start Address
+   0x00040000,                 // Device Size in Bytes (256kB)
+   1024,                       // Programming Page Size
+   0,                          // Reserved, must be 0
+   0xFF,                       // Initial Content of Erased Memory
+   100,                        // Program Page Timeout 100 mSec
+   3000,                       // Erase Sector Timeout 3000 mSec
+
+// Specify Size and Address of Sectors
+   0x002000, 0x000000,         // Sector Size  8kB (8 Sectors)
+   0x010000, 0x010000,         // Sector Size 64kB (2 Sectors) 
+   0x002000, 0x030000,         // Sector Size  8kB (8 Sectors)
+   SECTOR_END
+};