Patches for the 2010 problem

- Adjust the time base for NewtonScript time related functions to 2008-01-01T00:00:00 from 1993-01-01T00:00:00 - Set the Newton's time to the host time
pguyot · Jan 14, 2022 · 68373f9 · 68373f9
1 parent f64ccb9
commit 68373f9
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Showing 2 changed files with 78 additions and 25 deletions.
diff --git a/Emulator/JIT/Generic/TJITGenericROMPatch.cpp b/Emulator/JIT/Generic/TJITGenericROMPatch.cpp
@@ -104,6 +104,81 @@ T_ROM_PATCH(0x0038CE70, kROMPatchVoid, kROMPatchVoid,  kROMPatchVoid, "Debugger"
     return 0L;
 }
 
+/*
+ * Set the time to the host time
+ */
+
+static const KUInt32 delta1904to1970 = 2082844800;
+
+T_ROM_PATCH(0x00255578, kROMPatchVoid, kROMPatchVoid,  kROMPatchVoid, "RealClockSeconds")
+{
+    (void) ioUnit;
+    time_t t = time(NULL);
+    struct tm gm;
+    struct tm local;
+#if TARGET_OS_WIN32
+    gmtime_s(&gm, &t);
+    localtime_s(&local, &t);
+#else
+    gmtime_r(&t, &gm);
+    localtime_r(&t, &local);
+#endif
+    double tzoffset = difftime(mktime(&local), mktime(&gm));
+    ioCPU->SetRegister(0, t + tzoffset + delta1904to1970);
+    ioCPU->SetRegister(15, ioCPU->GetRegister(14) + 4);
+    return 0L;
+}
+
+/* Patches for the 2010 problem:
+ *
+ * The low level NewtonOS clock will continue to run with seconds since
+ * 1904-01-01T00:00:00. The NewtonScript functions which have been using a time
+ * base of 1993-01-01T00:00:00 will however be patched so that they will use a
+ * new time base of 2008-01-01T00:00:00. The patches will add or substract the
+ * delta between the time bases.
+ *
+ * The base year will need to be updated in 2026.
+ */
+
+/* Delta from 2008-01-01T00:00:00 to 1993-01-01T00:00:00 */
+
+static const KUInt32 safeIntervalDeltaSeconds = 473299200;
+
+/*
+ * Adjust seconds values returned to NS layer into safe interval
+ */
+
+T_ROM_PATCH(0x00089B80, kROMPatchVoid, kROMPatchVoid,  kROMPatchVoid, "FTimeInSeconds")
+{
+    ioCPU->SetRegister(0, (ioCPU->GetRegister(0) - safeIntervalDeltaSeconds) << 2);
+    return ioUnit;
+}
+
+/*
+ * Fix date from seconds returned to NS layer
+ */
+
+T_ROM_PATCH(0x0008A8A8, kROMPatchVoid, kROMPatchVoid,  kROMPatchVoid, "FDateFromSeconds")
+{
+    ioCPU->SetRegister(1, ioCPU->GetRegister(1) + safeIntervalDeltaSeconds);
+    ioCPU->SetRegister(0, ioCPU->GetRegister(13));
+    return ioUnit;
+}
+
+static const KUInt32 newTimeBaseMinutes = 218799360; /* 2008/1/1 in minutes from 1904/1/1 as NS integer */
+static const KUInt32 newTimeBaseSeconds = 3281990400; /* 2008/1/1 in seconds from 1904/1/1 as NS integer */
+
+TJITGenericPatch timeBase1(0x420750, kROMPatchVoid, kROMPatchVoid, kROMPatchVoid,
+                           newTimeBaseMinutes, "Time base (1/4)");
+TJITGenericPatch timeBase2(0x420798, kROMPatchVoid, kROMPatchVoid, kROMPatchVoid,
+                           newTimeBaseMinutes, "Time base (2/4)");
+TJITGenericPatch timeBase3(0x4dca14, kROMPatchVoid, kROMPatchVoid, kROMPatchVoid,
+                           newTimeBaseMinutes, "Time base (3/4)");
+TJITGenericPatch timeBase4(0x30F088, kROMPatchVoid, kROMPatchVoid, kROMPatchVoid,
+                           newTimeBaseSeconds, "Time base (4/4)");
+TJITGenericPatch ignoreSettingTime(0x0008A20C, kROMPatchVoid, kROMPatchVoid, kROMPatchVoid,
+                           0xe1a0f00e, "Ignore setting time"); // mov pc, lr
+
 // ========================================================================== //
 // MARK: -
 // TJITGenericPatchManager

diff --git a/app/FLTK/TFLApp.cpp b/app/FLTK/TFLApp.cpp
@@ -877,20 +877,16 @@ void TFLApp::UserActionInstallEssentials()
         // Y2K10
         addInstallerGroup("NewtonOS Y2K10 Fix");
         addInstallerText("NewtonOS has a bug in handling years past 18:48:31 on January 5, 2010. "
-                         "The patch below will fix all date issues until 2026.\n\n"
+                         "Einstein contains a fix for US MP2x00 MessagePads, but "
+                         "for eMates and German MP2x00 MessagePads, "
+			 "the patch below will fix all date issues until 2026.\n\n"
                          "Please install this patch before installing anything else, "
                          "as this will wipe your Newton's memory.");
         addInstallerLink("explained by Eckhart Köppen", new StringList {
             ":https://40hz.org/Pages/newton/hacking/newton-year-2010-problem/"} );
         addInstallerLink("Readme file for the patch", new StringList {
             "MDownloads/Einstein/Essentials/y2k10/README.txt"} );
         addInstallerText("Please select the patch that matches the ROM image of your machine:");
-        addInstallerPackage("US MP2x00 patch", new StringList {
-            "WInstalling this patch may irreversibly erase all data\n"
-            "on your MessagePad.\n\n"
-            "Please proceed only if this a new device, or if your\n"
-            "data is securely backed up!",
-            "MDownloads/Einstein/Essentials/y2k10/Patch_US.pkg"} );
         addInstallerPackage("German MP2x00 patch", new StringList {
             "WInstalling this patch may irreversibly erase all data\n"
             "on your MessagePad.\n\n"
@@ -1318,24 +1314,6 @@ void TFLApp::StoreAppWindowSize()
  */
 void TFLApp::DeferredOnPowerRestored()
 {
-    static bool beenHere = false;
-
-    // We run this once at boot time. It would be correct to reset this whenever
-    // we reboot or load a different configuration.
-    if (!beenHere) {
-        if (mFLSettings->mFetchDateAndTime) {
-            std::time_t now = time(nullptr);
-            struct std::tm then_tm = { 0, 0, 0, 1, 0, 4 }; /* Midnight Jan 1 1904 */
-            std::time_t then = std::mktime(&then_tm);
-            auto diff_secs = std::difftime(now, then);
-
-            KUInt32 minutesSince1904 = (KUInt32)(diff_secs / 60);
-            char setTimeAndDateScript[256];
-            ::snprintf(setTimeAndDateScript, 256, "SetTime(%u);", minutesSince1904);
-            mPlatformManager->EvalNewtonScript(setTimeAndDateScript);
-        }
-        beenHere = true;
-    }
 }