Combine BACK and END entries in CMS menus in a single item

As suggested by @hydra. OME_Back and OME_END continue to be valid
items, but we now also have OME_BACK_AND_END which creates a back
entry and indicates the end of the menu, saving an entry. On F3,
this saves 464 bytes of flash.

src/main/cms/cms.c

@@ -207,6 +207,9 @@ static void cmsUpdateMaxRow(displayPort_t *instance)
 
     for (const OSD_Entry *ptr = pageTop; ptr->type != OME_END; ptr++) {
         pageMaxRow++;
+        if (ptr->type == OME_BACK_AND_END) {
+            break;
+        }
     }
 
     if (pageMaxRow >  MAX_MENU_ITEMS(instance)) {
@@ -516,6 +519,7 @@ static int cmsDrawMenuEntry(displayPort_t *pDisplay, const OSD_Entry *p, uint8_t
     case OME_OSD_Exit:
     case OME_END:
     case OME_Back:
+    case OME_BACK_AND_END:
         break;
 
     case OME_MENU:
@@ -592,8 +596,12 @@ static void cmsDrawMenu(displayPort_t *pDisplay, uint32_t currentTimeUs)
             coloff += cmsElementIsLabel(p->type) ? 1 : 2;
             room -= displayWrite(pDisplay, coloff, i + top, p->text);
             CLR_PRINTLABEL(p, i);
-            if (room < 30)
+            if (room < 30) {
                 return;
+            }
+        }
+        if (p->type == OME_BACK_AND_END) {
+            break;
         }
     }
 
@@ -605,16 +613,25 @@ static void cmsDrawMenu(displayPort_t *pDisplay, uint32_t currentTimeUs)
     for (i = 0, p = pageTop; i < MAX_MENU_ITEMS(pDisplay) && p->type != OME_END; i++, p++) {
         if (IS_PRINTVALUE(p, i)) {
             room -= cmsDrawMenuEntry(pDisplay, p, top + i, i);
-            if (room < 30)
+            if (room < 30) {
                 return;
+            }
+        }
+        if (p->type == OME_BACK_AND_END) {
+            break;
         }
     }
 }
 
 static void cmsMenuCountPage(displayPort_t *pDisplay)
 {
     const OSD_Entry *p;
-    for (p = currentCtx.menu->entries; p->type != OME_END; p++);
+    for (p = currentCtx.menu->entries; p->type != OME_END; p++) {
+        if (p->type == OME_BACK_AND_END) {
+            p++;
+            break;
+        }
+    }
     pageCount = (p - currentCtx.menu->entries - 1) / MAX_MENU_ITEMS(pDisplay) + 1;
 }
 
@@ -722,6 +739,9 @@ static void cmsTraverseGlobalExit(const CMS_Menu *pMenu)
         if (p->type == OME_Submenu) {
             cmsTraverseGlobalExit(p->data);
         }
+        if (p->type == OME_BACK_AND_END) {
+            break;
+        }
     }
 
     if (pMenu->onGlobalExit) {
@@ -866,6 +886,7 @@ STATIC_UNIT_TESTED uint16_t cmsHandleKey(displayPort_t *pDisplay, uint8_t key)
             break;
 
         case OME_Back:
+        case OME_BACK_AND_END:
             cmsMenuBack(pDisplay);
             res = BUTTON_PAUSE;
             break;

src/main/cms/cms_menu_battery.c

@@ -109,8 +109,7 @@ static const OSD_Entry menuBattSettingsEntries[]=
     OSD_SETTING_ENTRY("CAP WARN", SETTING_BATTERY_CAPACITY_WARNING),
     OSD_SETTING_ENTRY("CAP CRIT", SETTING_BATTERY_CAPACITY_CRITICAL),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static CMS_Menu cmsx_menuBattSettings = {
@@ -134,8 +133,7 @@ static OSD_Entry menuBatteryEntries[]=
     OSD_UINT8_CALLBACK_ENTRY("PROF", cmsx_onBatteryProfileIndexChange, (&(const OSD_UINT8_t){ &battDispProfileIndex, 1, MAX_BATTERY_PROFILE_COUNT, 1})),
     OSD_SUBMENU_ENTRY("SETTINGS", &cmsx_menuBattSettings),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY
+    OSD_BACK_AND_END_ENTRY,
 };
 
 CMS_Menu cmsx_menuBattery = {

src/main/cms/cms_menu_blackbox.c

@@ -86,8 +86,7 @@ static const OSD_Entry cmsx_menuBlackboxEntries[] =
     OSD_FUNC_CALL_ENTRY("ERASE FLASH", cmsx_EraseFlash),
 #endif // USE_FLASHFS
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuBlackbox = {

src/main/cms/cms_menu_builtin.c

@@ -86,8 +86,7 @@ static const OSD_Entry menuInfoEntries[] = {
     OSD_STRING_ENTRY("GITREV", infoGitRev),
     OSD_STRING_ENTRY("TARGET", infoTargetName),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu menuInfo = {
@@ -128,8 +127,7 @@ static const OSD_Entry menuFeaturesEntries[] =
     OSD_SUBMENU_ENTRY("LED STRIP", &cmsx_menuLedstrip),
 #endif // LED_STRIP
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu menuFeatures = {

src/main/cms/cms_menu_imu.c

@@ -142,8 +142,7 @@ static const OSD_Entry cmsx_menuPidEntries[] =
     OSD_UINT8_ENTRY("YAW   I", (&(const OSD_UINT8_t){ &cmsx_pidYaw[1],   0, 200, 1 })),
     OSD_UINT8_ENTRY("YAW   D", (&(const OSD_UINT8_t){ &cmsx_pidYaw[2],   0, 200, 1 })),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuPid = {
@@ -198,8 +197,7 @@ static const OSD_Entry cmsx_menuPidAltMagEntries[] =
 
     OSD_UINT8_ENTRY("MAG P", (&(const OSD_UINT8_t){ &cmsx_pidHead[0], 0, 255, 1 })),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuPidAltMag = {
@@ -248,8 +246,7 @@ static const OSD_Entry cmsx_menuPidGpsnavEntries[] =
     OSD_UINT8_ENTRY("POSR I", (&(const OSD_UINT8_t){ &cmsx_pidVelXY[1], 0, 255, 1 })),
     OSD_UINT8_ENTRY("POSR D", (&(const OSD_UINT8_t){ &cmsx_pidVelXY[2], 0, 255, 1 })),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuPidGpsnav = {
@@ -277,8 +274,7 @@ static const OSD_Entry cmsx_menuManualRateProfileEntries[] =
     OSD_SETTING_ENTRY("MANU RC EXPO", SETTING_MANUAL_RC_EXPO),
     OSD_SETTING_ENTRY("MANU RC YAW EXP", SETTING_MANUAL_RC_YAW_EXPO),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuManualRateProfile = {
@@ -317,8 +313,7 @@ static const OSD_Entry cmsx_menuRateProfileEntries[] =
     OSD_SETTING_ENTRY("THRPID ATT", SETTING_TPA_RATE),
     OSD_SETTING_ENTRY_STEP("TPA BRKPT", SETTING_TPA_BREAKPOINT, 10),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuRateProfile = {
@@ -376,8 +371,7 @@ static const OSD_Entry cmsx_menuProfileOtherEntries[] = {
     { "HORZN STR",   OME_UINT8, NULL, &(OSD_UINT8_t){ &cmsx_horizonStrength,     0, 200, 1 }    , 0 },
     { "HORZN TRS",   OME_UINT8, NULL, &(OSD_UINT8_t){ &cmsx_horizonTransition,   0, 200, 1 }    , 0 },
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuProfileOther = {
@@ -404,8 +398,7 @@ static const OSD_Entry cmsx_menuFilterPerProfileEntries[] =
     OSD_SETTING_ENTRY("YAW P LIM", SETTING_YAW_P_LIMIT),
     OSD_SETTING_ENTRY("YAW LPF", SETTING_YAW_LPF_HZ),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuFilterPerProfile = {
@@ -426,8 +419,7 @@ static const OSD_Entry cmsx_menuGyroEntries[] =
     OSD_SETTING_ENTRY("GYRO SYNC", SETTING_GYRO_SYNC),
     OSD_SETTING_ENTRY("GYRO LPF", SETTING_GYRO_HARDWARE_LPF),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuGyro = {
@@ -466,8 +458,7 @@ static const OSD_Entry cmsx_menuImuEntries[] =
     {"FILT GLB",  OME_Submenu, cmsMenuChange,                 &cmsx_menuFilterGlobal,                                      0},
 #endif
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuImu = {

src/main/cms/cms_menu_ledstrip.c

@@ -60,8 +60,7 @@ static const OSD_Entry cmsx_menuLedstripEntries[] =
     OSD_LABEL_ENTRY("-- LED STRIP --"),
     OSD_BOOL_FUNC_ENTRY("ENABLED", cmsx_FeatureLedStrip_Enabled),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuLedstrip = {

src/main/cms/cms_menu_misc.c

@@ -67,8 +67,7 @@ static const OSD_Entry cmsx_menuRcEntries[] =
     OSD_INT16_RO_ENTRY("AUX3", &rcData[AUX3]),
     OSD_INT16_RO_ENTRY("AUX4", &rcData[AUX4]),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuRcPreview = {
@@ -94,8 +93,7 @@ static const OSD_Entry menuMiscEntries[]=
 
     OSD_SUBMENU_ENTRY("RC PREV", &cmsx_menuRcPreview),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuMisc = {

src/main/cms/cms_menu_navigation.c

@@ -52,8 +52,7 @@ static const OSD_Entry cmsx_menuNavSettingsEntries[] =
     OSD_SETTING_ENTRY("MID THR FOR AH", SETTING_NAV_USE_MIDTHR_FOR_ALTHOLD),
     OSD_SETTING_ENTRY("MC HOVER THR", SETTING_NAV_MC_HOVER_THR),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
  };
 
 static const CMS_Menu cmsx_menuNavSettings = {
@@ -83,8 +82,7 @@ static const CMS_Menu cmsx_menuNavSettings = {
     OSD_SETTING_ENTRY("RTH ABORT THRES", SETTING_NAV_RTH_ABORT_THRESHOLD),
     OSD_SETTING_ENTRY("EMERG LANDING SPEED", SETTING_NAV_EMERG_LANDING_SPEED),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
  };
 
 static const CMS_Menu cmsx_menuRTH = {
@@ -111,8 +109,7 @@ static const OSD_Entry cmsx_menuFixedWingEntries[] =
     OSD_SETTING_ENTRY("PITCH TO THR RATIO", SETTING_NAV_FW_PITCH2THR),
     OSD_SETTING_ENTRY("LOITER RADIUS", SETTING_NAV_FW_LOITER_RADIUS),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuFixedWing = {
@@ -134,8 +131,7 @@ static const OSD_Entry cmsx_menuNavigationEntries[] =
     OSD_SUBMENU_ENTRY("RTH", &cmsx_menuRTH),
     OSD_SUBMENU_ENTRY("FIXED WING", &cmsx_menuFixedWing),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuNavigation = {

src/main/cms/cms_menu_osd.c

@@ -57,8 +57,7 @@ static const OSD_Entry cmsx_menuAlarmsEntries[] = {
     OSD_SETTING_ENTRY("MAX DIST", SETTING_OSD_DIST_ALARM),
     OSD_SETTING_ENTRY("MAX NEG ALT", SETTING_OSD_NEG_ALT_ALARM),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuAlarms = {
@@ -101,17 +100,15 @@ static const OSD_Entry menuOsdElemActionsEntries[] = {
     OSD_UINT8_CALLBACK_ENTRY("COLUMN", cmsx_osdElementOnChange, (&(const OSD_UINT8_t){ &osdCurrentElementColumn, 0, OSD_Y(OSD_POS_MAX), 1 })),
     OSD_FUNC_CALL_ENTRY("PREVIEW", osdElementPreview),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const OSD_Entry menuOsdFixedElemActionsEntries[] = {
 
     OSD_BOOL_CALLBACK_ENTRY("ENABLED", cmsx_osdElementOnChange, &osdCurrentElementVisible),
     OSD_FUNC_CALL_ENTRY("PREVIEW", osdElementPreview),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static CMS_Menu cmsx_menuOsdElementActions = {
@@ -261,15 +258,14 @@ static const OSD_Entry menuOsdElemsEntries[] =
     OSD_ELEMENT_ENTRY("SENSOR 7 TEMP", OSD_TEMP_SENSOR_7_TEMPERATURE),
 #endif
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 #if defined(USE_GPS) && defined(USE_BARO) && defined(USE_PITOT) && defined(USE_TEMPERATURE_SENSOR)
-// All CMS OSD elements should be enabled in this case. The menu has 3 extra
-// elements (label, back and end), but there's an OSD element that we intentionally
+// All CMS OSD elements should be enabled in this case. The menu has 2 extra
+// elements (label, back+end), but there's an OSD element that we intentionally
 // don't show here (OSD_DEBUG).
-_Static_assert(ARRAYLEN(menuOsdElemsEntries) - 3 + 1 == OSD_ITEM_COUNT, "missing OSD elements in CMS");
+_Static_assert(ARRAYLEN(menuOsdElemsEntries) - 2 + 1 == OSD_ITEM_COUNT, "missing OSD elements in CMS");
 #endif
 
 const CMS_Menu menuOsdElements = {
@@ -301,8 +297,7 @@ static const OSD_Entry cmsx_menuOsdLayoutEntries[] =
 #endif
 #endif
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuOsdLayout = {
@@ -344,9 +339,7 @@ static const OSD_Entry menuOsdSettingsEntries[] = {
     OSD_SETTING_ENTRY("RIGHT SCROLL", SETTING_OSD_RIGHT_SIDEBAR_SCROLL),
     OSD_SETTING_ENTRY("SCROLL ARROWS", SETTING_OSD_SIDEBAR_SCROLL_ARROWS),
 
-
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu cmsx_menuOsdSettings = {
@@ -367,8 +360,7 @@ static const OSD_Entry menuOsdEntries[] = {
     OSD_SUBMENU_ENTRY("SETTINGS", &cmsx_menuOsdSettings),
     OSD_SUBMENU_ENTRY("ALARMS", &cmsx_menuAlarms),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 

src/main/cms/cms_menu_vtx.c

@@ -128,8 +128,7 @@ static const OSD_Entry cmsx_menuVtxEntries[] =
     OSD_BOOL_ENTRY("LOW POWER", &masterConfig.vtx_power),
 #endif // USE_RTC6705
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuVtx = {

src/main/cms/cms_menu_vtx_ffpv.c

@@ -173,8 +173,7 @@ static const OSD_Entry ffpvCmsMenuCommenceEntries[] =
     OSD_LABEL_ENTRY("CONFIRM"),
     OSD_FUNC_CALL_ENTRY("YES", ffpvCmsCommence),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 static const CMS_Menu ffpvCmsMenuCommence = {
@@ -199,8 +198,7 @@ static const OSD_Entry ffpvMenuEntries[] =
     OSD_TAB_CALLBACK_ENTRY("POWER", ffpvCmsConfigPower, &ffpvCmsEntPower),
     OSD_SUBMENU_ENTRY("SET", &ffpvCmsMenuCommence),
 
-    OSD_BACK_ENTRY,
-    OSD_END_ENTRY,
+    OSD_BACK_AND_END_ENTRY,
 };
 
 const CMS_Menu cmsx_menuVtxFFPV = {