DMR-данные (SMS) на TYT MD-UV380 под OpenGD77

Восстановлено из транскрипта сессии после потери рабочего дерева на сервере сборки.

Что внутри:
- четыре новых модуля прошивки (приём, сборка исходящего, меню Messages);
- правки существующих файлов в виде скриптов, с порядком применения;
- инструменты стенда: снятие экрана рации по USB, дамп кадров, эталонная сборка пакета;
- NOTES.md: что проверено в эфире, что не доделано, где грабли.

Работало в эфире в августе 2026: данные ходят в обе стороны в режиме хотспота,
рация принимает SMS и показывает на экране. Отправка собрана и сверена с эталоном
сервера побайтово, но в эфире не проверялась.

Claude-Session: https://claude.ai/code/session_01GJtvG5WwqYNe1b7s9LLtgy

patches/patch_usbexit.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+"""Leave modem mode when the USB host goes away, instead of after a fixed timeout.
+
+Stock firmware dropped out of hotspot mode if the host was quiet for 20 seconds, which
+made the radio unusable as a permanently attached modem - so that timeout was disabled
+on request. The side effect was that the radio then stayed a modem forever and had to be
+power cycled by hand after every test.
+
+This ties the exit to the actual USB connection state instead: while the host is present
+the radio stays a modem no matter how quiet it is, and as soon as the cable is pulled (or
+the host stops enumerating it) the radio returns to normal operation by itself.
+"""
+W = "/home/viktor/ogd77rel/uv_src/OpenGD77_MDUV380_DM1701_20260130/MDUV380_firmware/application"
+p = W + "/source/functions/hotspot.c"
+s = open(p).read()
+
+if "usbHostIsAttached" in s:
+    print("already patched")
+    raise SystemExit(0)
+
+# a small helper next to the other statics
+anchor = "static const uint32_t MMDVMHOST_TIMEOUT = MMDVMHOST_TIMEOUT_DISABLED;\n"
+assert anchor in s, "timeout constant not found"
+
+helper = anchor + """
+// The USB device handle tells us whether a host is actually enumerating us. Losing that
+// is what "the computer went away" really means; host silence alone is not.
+extern USBD_HandleTypeDef hUsbDeviceFS;
+
+static bool usbHostIsAttached(void)
+{
+	return (hUsbDeviceFS.dev_state == USBD_STATE_CONFIGURED);
+}
+"""
+s = s.replace(anchor, helper, 1)
+
+# make sure the USB device header is included
+if '#include "usb_device.h"' not in s:
+    inc_anchor = '#include "functions/ticks.h"\n'
+    assert inc_anchor in s, "include anchor missing"
+    s = s.replace(inc_anchor, inc_anchor + '#include "usb_device.h"\n', 1)
+
+# both inactivity checks now also fire when the host has disconnected
+old = """				if ((MMDVMHOST_TIMEOUT != 0) && (nonVolatileSettings.hotspotType == HOTSPOT_TYPE_MMDVM) &&
+						((ticksGetMillis() - mmdvmHostLastActiveTime) > MMDVMHOST_TIMEOUT))
+"""
+new = """				if ((nonVolatileSettings.hotspotType == HOTSPOT_TYPE_MMDVM) &&
+						((usbHostIsAttached() == false) ||
+						 ((MMDVMHOST_TIMEOUT != 0) && ((ticksGetMillis() - mmdvmHostLastActiveTime) > MMDVMHOST_TIMEOUT))))
+"""
+count = s.count(old)
+assert count == 2, "expected 2 inactivity checks, found %d" % count
+s = s.replace(old, new)
+
+open(p, "w").write(s)
+print("hotspot.c: modem mode now ends when the USB host disconnects (%d checks)" % count)