rosalina: split ntp and timeoffset nullification

- NTP option doesn't require a reboot to take effect anymore and behaves as if you'd used System Settings, taking effect immediately. This is the proper way to do it, and is easier to use.
- Timeoffset nullification kept as a separate option for compatibility. RTC is supposed to be somehwat monotonic; using this option causes issues with SpotPass. IMHO GodMode9 should parse the cfg save file and do things *properly*

sysmodules/rosalina/include/menus/miscellaneous.h

@@ -35,4 +35,5 @@ void MiscellaneousMenu_SwitchBoot3dsxTargetTitle(void);
 void MiscellaneousMenu_ChangeMenuCombo(void);
 void MiscellaneousMenu_SaveSettings(void);
 void MiscellaneousMenu_InputRedirection(void);
-void MiscellaneousMenu_SyncTimeDate(void);
+void MiscellaneousMenu_UpdateTimeDateNtp(void);
+void MiscellaneousMenu_NullifyUserTimeOffset(void);

sysmodules/rosalina/include/ntp.h

@@ -31,3 +31,4 @@
 
 Result ntpGetTimeStamp(time_t *outTimestamp);
 Result ntpSetTimeDate(time_t timestamp);
+Result ntpNullifyUserTimeOffset(void); // not actually used for NTP

sysmodules/rosalina/source/menus/miscellaneous.c

@@ -43,7 +43,8 @@ Menu miscellaneousMenu = {
         { "Switch the hb. title to the current app.", METHOD, .method = &MiscellaneousMenu_SwitchBoot3dsxTargetTitle },
         { "Change the menu combo", METHOD, .method = &MiscellaneousMenu_ChangeMenuCombo },
         { "Start InputRedirection", METHOD, .method = &MiscellaneousMenu_InputRedirection },
-        { "Sync time and date via NTP", METHOD, .method = &MiscellaneousMenu_SyncTimeDate },
+        { "Update time and date via NTP", METHOD, .method = &MiscellaneousMenu_UpdateTimeDateNtp },
+        { "Nullify user time offset", METHOD, .method = &MiscellaneousMenu_NullifyUserTimeOffset },
         { "Save settings", METHOD, .method = &MiscellaneousMenu_SaveSettings },
         {},
     }
@@ -344,7 +345,7 @@ void MiscellaneousMenu_InputRedirection(void)
     while(!(waitInput() & KEY_B) && !menuShouldExit);
 }
 
-void MiscellaneousMenu_SyncTimeDate(void)
+void MiscellaneousMenu_UpdateTimeDateNtp(void)
 {
     u32 posY;
     u32 input = 0;
@@ -415,7 +416,7 @@ void MiscellaneousMenu_SyncTimeDate(void)
         else if (R_FAILED(res))
             Draw_DrawFormattedString(10, posY + 2 * SPACING_Y, COLOR_WHITE, "Operation failed (%08lx).", (u32)res) + SPACING_Y;
         else
-            Draw_DrawFormattedString(10, posY + 2 * SPACING_Y, COLOR_WHITE, "Timedate & RTC updated successfully.\nYou may need to reboot to see the changes.") + SPACING_Y;
+            Draw_DrawFormattedString(10, posY + 2 * SPACING_Y, COLOR_WHITE, "Time/date updated successfully.") + SPACING_Y;
 
         input = waitInput();
 
@@ -425,3 +426,27 @@ void MiscellaneousMenu_SyncTimeDate(void)
     while(!(input & KEY_B) && !menuShouldExit);
 
 }
+
+
+void MiscellaneousMenu_NullifyUserTimeOffset(void)
+{
+    Result res = ntpNullifyUserTimeOffset();
+
+    Draw_Lock();
+    Draw_ClearFramebuffer();
+    Draw_FlushFramebuffer();
+    Draw_Unlock();
+
+    do
+    {
+        Draw_Lock();
+        Draw_DrawString(10, 10, COLOR_TITLE, "Miscellaneous options menu");
+        if(R_SUCCEEDED(res))
+            Draw_DrawString(10, 30, COLOR_WHITE, "Operation succeeded.\n\nPlease reboot to finalize the changes.");
+        else
+            Draw_DrawFormattedString(10, 30, COLOR_WHITE, "Operation failed (0x%08lx).", res);
+        Draw_FlushFramebuffer();
+        Draw_Unlock();
+    }
+    while(!(waitInput() & KEY_B) && !menuShouldExit);
+}

sysmodules/rosalina/source/ntp.c

@@ -29,6 +29,7 @@
 #include <string.h>
 #include "utils.h"
 #include "minisoc.h"
+#include "ntp.h"
 
 #define NUM2BCD(n)          ((n<99) ? (((n/10)*0x10)|(n%10)) : 0x99)
 
@@ -144,6 +145,21 @@ Result ntpSetTimeDate(time_t timestamp)
     Result res = ptmSysmInit();
     if (R_FAILED(res)) return res;
 
+    // Update the user time offset
+    // 946684800 is the timestamp of 01/01/2000 00:00 relative to the Unix Epoch
+    s64 msY2k = (timestamp - 946684800) * 1000;
+    res = PTMSYSM_SetUserTime(msY2k);
+
+    ptmSysmExit();
+    return res;
+}
+
+// Not actually used for NTP, but...
+Result ntpNullifyUserTimeOffset(void)
+{
+    Result res = ptmSysmInit();
+    if (R_FAILED(res)) return res;
+
     res = cfguInit();
     if (R_FAILED(res))
     {
@@ -151,19 +167,25 @@ Result ntpSetTimeDate(time_t timestamp)
         return res;
     }
 
-    // First, set the config RTC offset to 0
-    u8 rtcOff[8] = {0};
-    res = CFG_SetConfigInfoBlk4(8, 0x30001, rtcOff);
+    // First, set the user time offset to 0 (user time = rtc time + user time offset)
+    s64 userTimeOff = 0;
+    res = CFG_SetConfigInfoBlk4(8, 0x30001, &userTimeOff);
     if (R_FAILED(res)) goto cleanup;
 
-    // Update the RTC
-    // 946684800 is the timestamp of 01/01/2000 00:00 relative to the Unix Epoch
-    s64 msY2k = (timestamp - 946684800) * 1000;
-    res = PTMSYSM_SetRtcTime(msY2k);
+    // Get the user time from shared data... there might be up to 0.5s drift from {mcu+offset} but we don't care here
+    s64 userTime = osGetTime() - 3155673600000LL; // 1900 -> 2000 time base
+
+    // Apply user time to RTC
+    res = PTMSYSM_SetRtcTime(userTime);
     if (R_FAILED(res)) goto cleanup;
 
+    // Invalidate system (absolute, server) time, which gets fixed on "friends" login anyway -- don't care if we fail here.
+    // It has become invalid because we changed the RTC time
+    PTMSYSM_InvalidateSystemTime();
+
     // Save the config changes
     res = CFG_UpdateConfigSavegame();
+
     cleanup:
     ptmSysmExit();
     cfguExit();