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)

hardware/dp32g030/gpio.def

@@ -0,0 +1,93 @@
+# Copyright 2023 Dual Tachyon
+# https://github.com/DualTachyon
+#
+# 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
+#
+#     http://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.
+
+[GPIO]
+$ = GPIO_Bank_t
+
+DATA = 0x0000
+DIR = 0x0004
+> 0, 0, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 1, 1, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 2, 2, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 3, 3, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 4, 4, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 5, 5, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 6, 6, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 7, 7, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 8, 8, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 9, 9, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 10, 10, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 11, 11, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 12, 12, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 13, 13, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 14, 14, 1
+= INPUT, 0
+= OUTPUT, 1
+
+> 15, 15, 1
+= INPUT, 0
+= OUTPUT, 1
+
+[GPIOA]
+@ = 0x40060000, 0x800, $GPIO
+
+[GPIOB]
+@ = 0x40060800, 0x800, $GPIO
+
+[GPIOC]
+@ = 0x40061000, 0x800, $GPIO
+