Magical Backup

2026-01-18 16:27:34 +01:00 · 2022-05-19 19:50:27 +02:00
parent 833bc4a120
commit 8e543f30c9
22 changed files with 265 additions and 21 deletions
--- a/bootloader/Makefile
+++ b/bootloader/Makefile
@@ -37,6 +37,7 @@ bootloader_src += $(addprefix bootloader/interface/menus/, \
  warning.cpp \
  slot_recovery.cpp \
  crash.cpp \
+  upsilon_recovery.cpp \
 )

 bootloader_images = $(addprefix bootloader/, \
--- a/bootloader/boot.cpp
+++ b/bootloader/boot.cpp
@@ -65,7 +65,7 @@ bool Boot::isKernelPatched(const Slot & s) {
  return  *(uint32_t *)(origin_isr + sizeof(uint32_t) * 7) == ((uint32_t)&_fake_isr_function_start) + 1;
 }

-__attribute((section(".fake_isr_function"))) __attribute__((used)) void Boot::flash_interrupt() {
+__attribute__((section(".fake_isr_function"))) __attribute__((used)) void Boot::flash_interrupt() {
  // a simple function
  Ion::Device::Flash::ClearInternalFlashErrors();
  asm("bx lr");
--- a/bootloader/boot.h
+++ b/bootloader/boot.h
@@ -47,7 +47,7 @@ public:
  static void bootSlot(Bootloader::Slot slot);
  static void bootSelectedSlot();
  __attribute__ ((noreturn)) static void jumpToInternalBootloader(); 
-  __attribute((section(".fake_isr_function"))) __attribute__((used)) static void flash_interrupt();
+  __attribute__ ((section(".fake_isr_function"))) __attribute__((used)) static void flash_interrupt();

  static void bootloader();
  static void lockInternal();
--- a/bootloader/interface/menus/upsilon_recovery.cpp
+++ b/bootloader/interface/menus/upsilon_recovery.cpp
@@ -0,0 +1,46 @@
+#include "upsilon_recovery.h"
+#include <bootloader/slots/slot.h>
+#include <bootloader/usb_data.h>
+#include <ion/src/device/shared/drivers/board.h>
+#include <ion.h>
+#include <stdlib.h>
+
+extern "C" void jump_to_firmware(const uint32_t* stackPtr, const void(*startPtr)(void));
+
+Bootloader::UpsilonRecoveryMenu::UpsilonRecoveryMenu() : Menu(KDColorBlack, KDColorWhite, Messages::upsilonRecoveryTitle, Messages::mainTitle) {
+    setup();
+}
+
+void Bootloader::UpsilonRecoveryMenu::setup() {
+  m_defaultColumns[0] = Column(Messages::upsilonRecoveryMessage1, k_small_font, 0, true);
+  m_defaultColumns[1] = Column(Messages::upsilonRecoveryMessage2, k_small_font, 0, true);
+  m_defaultColumns[2] = Column(Messages::upsilonRecoveryMessage3, k_small_font, 0, true);
+  m_defaultColumns[3] = Column(Messages::upsilonRecoveryMessage4, k_small_font, 0, true);
+  m_defaultColumns[4] = Column(Messages::upsilonRecoveryMessage5, k_small_font, 0, true);
+  
+  m_columns[0] = ColumnBinder(&m_defaultColumns[0]);
+  m_columns[1] = ColumnBinder(&m_defaultColumns[1]);
+  m_columns[2] = ColumnBinder(&m_defaultColumns[2]);
+  m_columns[3] = ColumnBinder(&m_defaultColumns[3]);
+  m_columns[4] = ColumnBinder(&m_defaultColumns[4]);
+}
+
+void Bootloader::UpsilonRecoveryMenu::postOpen() {
+  // We override the open method
+  for (;;) {
+    uint64_t scan = Ion::Keyboard::scan();
+    if (scan == Ion::Keyboard::State(Ion::Keyboard::Key::Back)) {
+      while (Ion::Keyboard::scan() == Ion::Keyboard::State(Ion::Keyboard::Key::Back));
+      forceExit();
+      return;
+    } else if (scan == Ion::Keyboard::State(Ion::Keyboard::Key::OnOff)) {
+      Ion::Power::standby();
+      return;
+    } else if (scan == Ion::Keyboard::State(Ion::Keyboard::Key::OK)) {
+      Slot slot = Slot::Upsilon();
+      Ion::Device::Board::bootloaderMPU();
+      jump_to_firmware(slot.kernelHeader()->stackPointer(), slot.userlandHeader()->upsilonRecoveryBootFunction());
+      for(;;);
+    }
+  }
+}
--- a/bootloader/interface/menus/upsilon_recovery.h
+++ b/bootloader/interface/menus/upsilon_recovery.h
@@ -0,0 +1,15 @@
+#ifndef _BOOTLOADER_INTERFACE_MENUS_UPSILON_RECOVERY_H_
+#define _BOOTLOADER_INTERFACE_MENUS_UPSILON_RECOVERY_H_
+
+#include <bootloader/interface/src/menu.h>
+
+namespace Bootloader {
+  class UpsilonRecoveryMenu : public Menu {
+    public:
+      UpsilonRecoveryMenu();
+      void setup() override;
+      void postOpen() override;
+  };
+}
+
+#endif
--- a/bootloader/interface/src/menu.h
+++ b/bootloader/interface/src/menu.h
@@ -9,10 +9,10 @@ namespace Bootloader {
  class Menu {
    public:
      Menu() : Menu(KDColorBlack, KDColorWhite, Messages::mainTitle) { };
-      Menu(KDColor foreground, KDColor background, const char * title) : Menu(foreground, background, title,  nullptr) {};
-      Menu(KDColor foreground, KDColor background, const char * title, const char * bottom) : Menu(foreground, background, title, bottom, false) {};
-      Menu(KDColor foreground, KDColor background, const char * title, const char * bottom, bool centerY) :  Menu(foreground, background, title, bottom, centerY, k_columns_margin) {};
-      Menu(KDColor foreground, KDColor background, const char * title, const char * bottom, bool centerY, int margin) : m_columns(), m_defaultColumns(), m_slotColumns(), m_background(background), m_title(title), m_foreground(foreground), m_bottom(bottom), m_centerY(centerY), m_forced_exit(false), m_margin(margin) {
+      Menu(KDColor forground, KDColor background, const char * title) : Menu(forground, background, title,  nullptr) {};
+      Menu(KDColor forground, KDColor background, const char * title, const char * bottom) : Menu(forground, background, title, bottom, false) {};
+      Menu(KDColor forground, KDColor background, const char * title, const char * bottom, bool centerY) :  Menu(forground, background, title, bottom, centerY, k_columns_margin) {};
+      Menu(KDColor forground, KDColor background, const char * title, const char * bottom, bool centerY, int margin) : m_columns(), m_defaultColumns(), m_slotColumns(), m_background(background), m_title(title), m_foreground(forground), m_bottom(bottom), m_centerY(centerY), m_forced_exit(false), m_margin(margin) {
        setup();
      }
      static const int k_columns_margin = 5;
--- a/bootloader/interface/static/messages.h
+++ b/bootloader/interface/static/messages.h
@@ -53,6 +53,15 @@ public:
  constexpr static const char * recoveryMessage4 = "Press Back to continue.";
  constexpr static const char * recoveryMessage5 = "(you will not be able to recover your data !)";

+  // Upsilon Recovery menu
+  constexpr static const char * upsilonRecoveryTitle = "Upsilon Recovery";
+
+  constexpr static const char * upsilonRecoveryMessage1 = "The bootloader has detected a crash.";
+  constexpr static const char * upsilonRecoveryMessage2 = "Because you also have an Upsilon slot,";
+  constexpr static const char * upsilonRecoveryMessage3 = "you can recover your data by booting";
+  constexpr static const char * upsilonRecoveryMessage4 = "the Upsilon slot.";
+  constexpr static const char * upsilonRecoveryMessage5 = "Press OK to continue, BACK to cancel";
+
  // Warning menu
  constexpr static const char * epsilonWarningTitle = "Epsilon Slot";

--- a/bootloader/recovery.cpp
+++ b/bootloader/recovery.cpp
@@ -1,6 +1,7 @@
 #include <bootloader/recovery.h>
 #include <ion.h>
 #include <ion/src/device/n0110/drivers/power.h>
+#include <ion/src/device/shared/drivers/bldata.h>
 #include <ion/src/device/shared/drivers/reset.h>
 #include <ion/src/device/shared/drivers/board.h>
 #include <assert.h>
@@ -10,6 +11,7 @@
 #include <bootloader/usb_data.h>
 #include <bootloader/interface/menus/slot_recovery.h>
 #include <bootloader/interface/menus/crash.h>
+#include <bootloader/interface/menus/upsilon_recovery.h>

 constexpr static uint32_t MagicStorage = 0xEE0BDDBA;

@@ -76,7 +78,15 @@ void Bootloader::Recovery::recoverData() {
  Ion::Display::pushRectUniform(KDRect(0,0,320,240), KDColorWhite);
  Ion::Backlight::init();

-  USBData udata = USBData::Recovery((uint32_t)getSlotConcerned().getStorageAddress(), (uint32_t)getSlotConcerned().getStorageSize());
+  CrashedSlot slot = getSlotConcerned();
+
+  if (Slot::hasUpsilon() && Slot::Upsilon().userlandHeader()->hasUpsilonExtras()) {
+    Ion::Device::BootloaderSharedData::sharedBootloaderData()->setRecovery((uint32_t)slot.getStorageAddress(), slot.getStorageSize());
+    UpsilonRecoveryMenu reco = UpsilonRecoveryMenu();
+    reco.open();
+  }
+
+  USBData udata = USBData::Recovery((uint32_t)slot.getStorageAddress(), (uint32_t)slot.getStorageSize());
  
  SlotRecoveryMenu menu = SlotRecoveryMenu(&udata);
  menu.open();
--- a/bootloader/slots/slot.cpp
+++ b/bootloader/slots/slot.cpp
@@ -2,6 +2,7 @@
 #include <ion/src/device/shared/drivers/board.h>
 #include <ion/src/device/shared/drivers/flash.h>
 #include <bootloader/boot.h>
+#include <assert.h>

 extern "C" void jump_to_firmware(const uint32_t* stackPtr, const void(*startPtr)(void));

@@ -19,6 +20,15 @@ const Slot Slot::Khi() {
  return Slot(0x90180000);
 }

+const bool Slot::hasUpsilon() {
+  return (isFullyValid(A()) && A().userlandHeader()->isUpsilon()) || (isFullyValid(B()) && B().userlandHeader()->isUpsilon());
+}
+
+const Slot Slot::Upsilon() {
+  assert(hasUpsilon());
+  return (isFullyValid(A()) && A().userlandHeader()->isUpsilon()) ? A() : B();
+}
+
 const KernelHeader* Slot::kernelHeader() const {
  return m_kernelHeader;
 }
--- a/bootloader/slots/slot.h
+++ b/bootloader/slots/slot.h
@@ -24,6 +24,8 @@ public:
  static const Slot A();
  static const Slot B();
  static const Slot Khi();
+  static const bool hasUpsilon();
+  static const Slot Upsilon();

  static bool isFullyValid(const Slot& slot) {
    return slot.kernelHeader()->isValid() && slot.userlandHeader()->isValid();
--- a/bootloader/slots/userland_header.cpp
+++ b/bootloader/slots/userland_header.cpp
@@ -38,4 +38,12 @@ const size_t UserlandHeader::storageSize() const {
  return m_storageSizeRAM;
 }

+const bool UserlandHeader::hasUpsilonExtras() const {
+  return m_upsilonExtraMagicFooter == UpsilonMagic;
+}
+
+const void (*UserlandHeader::upsilonRecoveryBootFunction() const)() {
+  return m_recoveryAddress;
+}
+
 }
--- a/bootloader/slots/userland_header.h
+++ b/bootloader/slots/userland_header.h
@@ -17,6 +17,9 @@ public:
  const char * upsilonVersion() const;
  const void * storageAddress() const;
  const size_t storageSize() const;
+  const bool hasUpsilonExtras() const;
+  const void (*upsilonRecoveryBootFunction() const)();
+

 private:
  UserlandHeader();
@@ -42,6 +45,8 @@ private:
  const char m_UpsilonVersion[16];
  uint32_t m_osType;
  uint32_t m_upsilonMagicFooter;
+  const void (*m_recoveryAddress)();
+  uint32_t m_upsilonExtraMagicFooter;
 };

 extern const UserlandHeader* s_userlandHeaderA;
--- a/ion/src/device/bootloader/boot/rt0.cpp
+++ b/ion/src/device/bootloader/boot/rt0.cpp
@@ -1,11 +1,15 @@
 #include <stdint.h>
 #include <string.h>
 #include <ion.h>
+#include <ion/led.h>
+#include <ion/storage.h>
+#include <ion/internal_storage.h>
 #include <boot/isr.h>
 #include <drivers/board.h>
 #include <drivers/rtc.h>
 #include <drivers/reset.h>
 #include <drivers/timing.h>
+#include <drivers/bldata.h>

 typedef void (*cxx_constructor)();

@@ -14,6 +18,8 @@ extern "C" {
  extern char _data_section_start_ram;
  extern char _data_section_end_ram;
  extern char _bss_section_start_ram;
+  extern char _static_storage_start;
+  extern char _static_storage_end;
  extern char _bss_section_end_ram;
  extern cxx_constructor _init_array_start;
  extern cxx_constructor _init_array_end;
@@ -129,6 +135,49 @@ void __attribute__((noinline)) start() {
  abort();
 }

+void __attribute__((noinline)) __attribute__((section(".recovery_boot"))) __attribute__((used)) recovery_start() {
+  // Here we are in the recovery boot.
+  Ion::Device::Board::initFPU();
+  
+  bool is_recoverying = Ion::Device::BootloaderSharedData::sharedBootloaderData()->storageAddress() != 0;
+
+  if (is_recoverying) {
+    uint32_t address = Ion::Device::BootloaderSharedData::sharedBootloaderData()->storageAddress();
+    uint32_t size = Ion::Device::BootloaderSharedData::sharedBootloaderData()->storageSize();
+
+    size_t storageSize = (&_static_storage_end - &_static_storage_start);
+    
+    memcpy(&_static_storage_start, (void*)address, size);
+
+    size_t dataSectionLength = (&_data_section_end_ram - &_data_section_start_ram);
+    memcpy(&_data_section_start_ram, &_data_section_start_flash, dataSectionLength);
+
+    size_t bssSectionLength = (&_bss_section_end_ram - &_static_storage_end);
+    memset(&_static_storage_end, 0, bssSectionLength);
+  } else {
+    size_t dataSectionLength = (&_data_section_end_ram - &_data_section_start_ram);
+    memcpy(&_data_section_start_ram, &_data_section_start_flash, dataSectionLength);
+    size_t bssSectionLength = (&_bss_section_end_ram - &_bss_section_start_ram);
+    memset(&_bss_section_start_ram, 0, bssSectionLength);
+  }
+  
+  if (&_init_array_start != &_init_array_end) {
+    abort();
+  }
+  size_t isrSectionLength = (&_isr_vector_table_end_ram - &_isr_vector_table_start_ram);
+  memcpy(&_isr_vector_table_start_ram, &_isr_vector_table_start_flash, isrSectionLength);
+
+  Ion::Device::Board::init();
+
+  if (is_recoverying) {
+    Ion::LED::setColor(KDColorBlue);
+  }
+
+  jump_to_external_flash();
+
+  abort();
+}
+
 void __attribute__((interrupt, noinline)) isr_systick() {
  auto t = Ion::Device::Timing::MillisElapsed;
  t++;
--- a/ion/src/device/bootloader/bootloader_common.ld
+++ b/ion/src/device/bootloader/bootloader_common.ld
@@ -1,3 +1,4 @@
+BOOTLOADER_SHARED_OFFSET = 0x3d0;

 SECTIONS {
  .signed_payload_prefix ORIGIN(FLASH) : {
@@ -34,7 +35,14 @@ SECTIONS {
    _isr_vector_table_end_ram = .;
  } >SRAM

-  .exam_mode_buffer ORIGIN(FLASH) + SIZEOF(.signed_payload_prefix) + SIZEOF(.kernel_header) + SIZEOF(.isr_vector_table) : {
+  .bootloader_shared ORIGIN(SRAM) + BOOTLOADER_SHARED_OFFSET : AT(ORIGIN(FLASH) + SIZEOF(.signed_payload_prefix) + SIZEOF(.kernel_header) + SIZEOF(.isr_vector_table) + SIZEOF(.slot_info)) {
+    _bootloader_shared_start = .;
+    KEEP(*(.bootloader_shared))
+    KEEP(*(.bootloader_shared.*))
+    _bootloader_shared_end = .;
+  } >SRAM
+
+  .exam_mode_buffer ORIGIN(FLASH) + SIZEOF(.signed_payload_prefix) + SIZEOF(.kernel_header) + SIZEOF(.isr_vector_table) + SIZEOF(.bootloader_shared) + SIZEOF(.slot_info) : {
    . = ALIGN(4K);
    _exam_mode_buffer_start = .;
    KEEP(*(.exam_mode_buffer))
@@ -49,6 +57,13 @@ SECTIONS {
    KEEP(*(.userland_header));
  } > FLASH

+  .recovery_boot : {
+    . = ALIGN(4);
+    _recovery_boot_start = .;
+    KEEP(*(.recovery_boot));
+    _recovery_boot_end = .;
+  } >FLASH
+
  .text : {
    . = ALIGN(4);
    *(.text)
@@ -88,6 +103,17 @@ SECTIONS {
    _data_section_end_ram = .;
  } >SRAM AT> FLASH

+  /*
+   * We set the .static_storage right after the .data section, even if it's a bss region, because we need to fix it in memory.
+   */
+   .static_storage : {
+    . = ALIGN(4);
+    _bss_section_start_ram = .;
+    _static_storage_start = .;
+    KEEP (*(.static_storage))
+    _static_storage_end = .;
+   } > SRAM
+
  .bss : {
    /* The bss section contains data for all uninitialized variables
     * So like the .data section, it will go in RAM, but unlike the data section
@@ -96,7 +122,6 @@ SECTIONS {
     * Before execution, crt0 will erase that section of memory though, so we'll
     * need pointers to the beginning and end of this section. */
    . = ALIGN(4);
-    _bss_section_start_ram = .;
    *(.bss)
    *(.bss.*)
    /* The compiler may choose to allocate uninitialized global variables as
--- a/ion/src/device/bootloader/internal_flash.ld
+++ b/ion/src/device/bootloader/internal_flash.ld
@@ -8,6 +8,7 @@ MEMORY {
 STACK_SIZE = 32K;
 TRAMPOLINES_OFFSET = 0xE000;
 CUSTOM_TRAMPOLINES_OFFSET = 64K - 64;
+BOOTLOADER_SHARED_OFFSET = 0x3d0;

 SECTIONS {
  .isr_vector_table ORIGIN(INTERNAL_FLASH) : {
@@ -31,7 +32,16 @@ SECTIONS {
    KEEP(*(.header))
  } >INTERNAL_FLASH

-  .rodata : {
+  .bootloader_shared ORIGIN(SRAM) + BOOTLOADER_SHARED_OFFSET : AT(ORIGIN(INTERNAL_FLASH) + SIZEOF(.isr_vector_table) + SIZEOF(.header)) {
+    . = ORIGIN(SRAM) + BOOTLOADER_SHARED_OFFSET;
+    _bootloader_shared_start = .;
+    KEEP(*(.bootloader_shared))
+    KEEP(*(.bootloader_shared.*))
+    _bootloader_shared_end = .;
+  } >SRAM
+
+  .rodata ORIGIN(INTERNAL_FLASH) + SIZEOF(.isr_vector_table) + SIZEOF(.header) + SIZEOF(.bootloader_shared) : {
+
    . = ALIGN(4);
    *(.rodata)
    *(.rodata.*)
--- a/ion/src/device/bootloader/platform_info.cpp
+++ b/ion/src/device/bootloader/platform_info.cpp
@@ -17,6 +17,9 @@
 #error This file expects UPSILON_VERSION to be defined
 #endif

+extern "C" {
+  extern char _recovery_boot_start;
+}
 namespace Ion {
 extern char staticStorageArea[];
 }
@@ -72,7 +75,9 @@ public:
    m_upsilonMagicHeader(UpsilonMagic),
    m_UpsilonVersion{UPSILON_VERSION},
    m_osType(OSType),
-    m_upsilonMagicFooter(UpsilonMagic) { }
+    m_upsilonMagicFooter(UpsilonMagic),
+    m_recoveryAddress(((uint32_t)&_recovery_boot_start) + 1),
+    m_upsilonExtraMagicFooter(UpsilonMagic) { }

  const char * omegaVersion() const {
    assert(m_storageAddressRAM != nullptr);
@@ -128,6 +133,8 @@ private:
  const char m_UpsilonVersion[16];
  uint32_t m_osType;
  uint32_t m_upsilonMagicFooter;
+  uint32_t m_recoveryAddress;
+  uint32_t m_upsilonExtraMagicFooter;
 };

 const UserlandHeader __attribute__((section(".userland_header"), used)) k_userlandHeader;
--- a/ion/src/device/shared/boot/isr.h
+++ b/ion/src/device/shared/boot/isr.h
@@ -8,6 +8,7 @@ extern "C" {
 void start();
 void abort();
 void isr_systick();
+void recovery_start();

 #ifdef __cplusplus
 }
--- a/ion/src/device/shared/drivers/Makefile
+++ b/ion/src/device/shared/drivers/Makefile
@@ -26,4 +26,5 @@ ion_device_src += $(addprefix ion/src/device/shared/drivers/, \
  timing.cpp \
  usb.cpp \
  wakeup.cpp \
+  bldata.cpp \
 )
--- a/ion/src/device/shared/drivers/bldata.cpp
+++ b/ion/src/device/shared/drivers/bldata.cpp
@@ -0,0 +1,21 @@
+#include "bldata.h"
+#include <ion.h>
+#include <new>
+
+namespace Ion {
+  uint32_t staticSharedData[sizeof(Ion::Device::BootloaderSharedData)/sizeof(uint32_t)] __attribute__((section(".bootloader_shared"))) __attribute__((used)) = {0};
+
+  Device::BootloaderSharedData * Device::BootloaderSharedData::sharedBootloaderData() {
+    static BootloaderSharedData * sharedData = new (staticSharedData) BootloaderSharedData();
+    return sharedData;
+  }
+
+  Device::BootloaderSharedData::BootloaderSharedData() {
+    if (m_header != Magic || m_footer != Magic) {
+      m_header = Magic;
+      m_storageAddress = 0;
+      m_storageSize = 0;
+      m_footer = Magic;
+   }
+  }
+}
--- a/ion/src/device/shared/drivers/bldata.h
+++ b/ion/src/device/shared/drivers/bldata.h
@@ -0,0 +1,24 @@
+#include <ion.h>
+
+namespace Ion 
+{
+namespace Device
+{
+  class BootloaderSharedData {
+    public:
+      constexpr static uint32_t Magic = 0x626C6461;
+      static BootloaderSharedData * sharedBootloaderData();
+
+      BootloaderSharedData();
+
+      void setRecovery(uint32_t address, uint32_t size) { m_storageAddress = address; m_storageSize = size; }
+      uint32_t storageAddress() const { return m_storageAddress; }
+      uint32_t storageSize() const { return m_storageSize; }
+    private:
+      uint32_t m_header;
+      uint32_t m_storageAddress;
+      uint32_t m_storageSize;
+      uint32_t m_footer;
+  };
+}
+}
--- a/ion/src/shared/internal_storage.cpp
+++ b/ion/src/shared/internal_storage.cpp
@@ -336,18 +336,18 @@ void InternalStorage::destroyRecordsWithExtension(const char * extension) {
  }
 }

-InternalStorage::InternalStorage() :
-  m_magicHeader(Magic),
-  m_buffer(),
-  m_magicFooter(Magic),
-  m_delegate(nullptr),
-  m_lastRecordRetrieved(nullptr),
-  m_lastRecordRetrievedPointer(nullptr)
-{
+InternalStorage::InternalStorage() {
+  m_magicHeader = Magic;
+  
+  m_magicFooter = Magic;
+  m_delegate = nullptr;
+  m_lastRecordRetrieved = nullptr;
+  m_lastRecordRetrievedPointer = nullptr;
+  
  assert(m_magicHeader == Magic);
  assert(m_magicFooter == Magic);
  // Set the size of the first record to 0
-  overrideSizeAtPosition(m_buffer, 0);
+  // overrideSizeAtPosition(m_buffer, 0);
 }

 // PRIVATE
--- a/ion/src/shared/storage.cpp
+++ b/ion/src/shared/storage.cpp
@@ -6,7 +6,7 @@

 namespace Ion {

-uint32_t staticStorageArea[sizeof(Storage)/sizeof(uint32_t)] = {0};
+uint32_t __attribute__((section(".static_storage"))) staticStorageArea[sizeof(Storage)/sizeof(uint32_t)] = {0};

 Storage * Storage::sharedStorage() {
  static Storage * storage = new (staticStorageArea) Storage();