Make Clock Persistant.

gcc_nrf52.ld

@@ -3,14 +3,23 @@
 SEARCH_DIR(.)
 GROUP(-lgcc -lc -lnosys)
 
+NO_INIT_SIZE = 0x100;
+RAM_MAX = 64K;
 MEMORY
 {
   FLASH (rx) : ORIGIN = 0x00000, LENGTH = 0x78000
-  RAM (rwx) :  ORIGIN = 0x20000000, LENGTH = 0x10000
+  RAM (rwx) :  ORIGIN = 0x20000000, LENGTH = RAM_MAX - NO_INIT_SIZE
+  NOINIT (rwx): ORIGIN = ORIGIN(RAM) + LENGTH(RAM), LENGTH = NO_INIT_SIZE
 }
 
 SECTIONS
 {
+  noinit (NOLOAD):
+  {
+    PROVIDE(__start_noinit_data = .);
+    KEEP(*(.noinit))
+    PROVIDE(__stop_noinit_data = .);
+  } >NOINIT
 }
 
 SECTIONS

src/components/datetime/DateTimeController.cpp

@@ -5,6 +5,10 @@
 
 using namespace Pinetime::Controllers;
 
+void DateTime::SetCurrentTime(std::chrono::time_point<std::chrono::system_clock, std::chrono::nanoseconds> t) {
+  this->currentDateTime = t;
+}
+
 void DateTime::SetTime(
   uint16_t year, uint8_t month, uint8_t day, uint8_t dayOfWeek, uint8_t hour, uint8_t minute, uint8_t second, uint32_t systickCounter) {
   std::tm tm = {
@@ -67,11 +71,12 @@ void DateTime::UpdateTime(uint32_t systickCounter) {
   // Notify new day to SystemTask
   if (hour == 0 and not isMidnightAlreadyNotified) {
     isMidnightAlreadyNotified = true;
-    if(systemTask != nullptr)
+    if (systemTask != nullptr)
       systemTask->PushMessage(System::Messages::OnNewDay);
   } else if (hour != 0) {
     isMidnightAlreadyNotified = false;
   }
+  BackUpTime = currentDateTime;
 }
 
 const char* DateTime::MonthShortToString() {

src/components/datetime/DateTimeController.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <chrono>
+extern std::chrono::time_point<std::chrono::system_clock, std::chrono::nanoseconds> BackUpTime;
 
 namespace Pinetime {
   namespace System {
@@ -74,6 +75,7 @@ namespace Pinetime {
       }
 
       void Register(System::SystemTask* systemTask);
+      void SetCurrentTime(std::chrono::time_point<std::chrono::system_clock, std::chrono::nanoseconds> t);
 
     private:
       uint16_t year = 0;

src/main.cpp

@@ -124,7 +124,6 @@ Pinetime::Controllers::FS fs {spiNorFlash};
 Pinetime::Controllers::Settings settingsController {fs};
 Pinetime::Controllers::MotorController motorController {settingsController};
 
-
 Pinetime::Applications::DisplayApp displayApp(lcd,
                                               lvgl,
                                               touchPanel,
@@ -161,6 +160,9 @@ Pinetime::System::SystemTask systemTask(spi,
                                         heartRateApp,
                                         fs);
 
+uint32_t MAGIC_RAM __attribute__((section(".noinit")));
+std::chrono::time_point<std::chrono::system_clock, std::chrono::nanoseconds> BackUpTime __attribute__((section(".noinit")));
+
 void nrfx_gpiote_evt_handler(nrfx_gpiote_pin_t pin, nrf_gpiote_polarity_t action) {
   if (pin == pinTouchIrq) {
     systemTask.OnTouchEvent();
@@ -321,6 +323,13 @@ int main(void) {
   // retrieve version stored by bootloader
   Pinetime::BootloaderVersion::SetVersion(NRF_TIMER2->CC[0]);
 
+  // Check Magic Ram and reset lost variables
+  if (MAGIC_RAM == 0xDEADBEEF) {
+    dateTimeController.SetCurrentTime(BackUpTime);
+  } else {
+    MAGIC_RAM = 0xDEADBEEF;
+  }
+
   lvgl.Init();
 
   systemTask.Start();