Zigbee Switching Between Applications

Table of Contents

• Switching Between Two Zigbee Applications
  • 1. Summary
  • 2. Gecko SDK version
  • 3. Hardware Required
  • 4. Connections Required
  • 5. Setup
    • 5.1. Create Application for Area 0
    • 5.2. Create Application for Area 1
    • 5.3. Add a Custom Command to Switch
    • 5.4. Modify the Bootloader to Bootload Application According to Reset Cause
  • 6. How It Works
  • 7. .sls Projects Used
  • 8. How to Port to Another Part
  • 9. Special Notes

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Switching Between Two Zigbee Applications

1. Summary

This example demostrates how we put two Zigbee applicaiton images into one SoC (EFR32MG12) and switch between them.

In this case, we use a part with 1MB flash and divide it into two area:

Area	Address
0	0x0 ~ 0x80000
1	0x80000 ~ 0x100000

The bootloader selects the corresponding start address to boot according to the user command. By default, it boots from address 0x0.

In section 7.1.2 of UG266, there is another approach of support multiple applicaiton images in a single SoC. In this approach, we divide the internal flash into two parts.

• The application area where the running application will be put in.
• Storage area. This area can be configured as multiple slots.

When we need to switch between applications, the bootloader will choose one storage slot, and then copy the application image from this slot to the application area.

Comparing to the approach in UG266, the approach in this example is more efficient on ultilizing storage space.

2. Gecko SDK version

Gecko SDK Suite 2.7.

3. Hardware Required

• Wireless Starter Kit Main Board (BRD4001)
• EFR32MG12 2400/915 MHz 19 dBm Dual Band Radio Board (BRD4164A)

4. Connections Required

NA

5. Setup

5.1. Create Application for Area 0

Create a ZigbeeMinimal project, generate, then select this project and right click, "properties", change the symbol "FLASH_SIZE" to 512KB, so that this application will only use the flash space from 0x0 to 0x80000.

After that, build it and flash the generated image into the kit.

Notes: If you regenerate your project, you need to check and configure the symbol "FLASH_SZE" again.

5.2. Create Application for Area 1

Create a ZigbeeMinimal project, generate, then select this project and right click, "properties", change the symbol "FLASH_SIZE" to 512KB as well.

After that, we need to change the linker file so that this application can run from a different address other than the default (0x0).

Copy file "C:/SiliconLabs/SimplicityStudio/v4/developer/sdks/gecko_sdk_suite/v2.7/platform/base/hal/micro/cortexm3/efm32/gcc-cfg.ld" to "C:/SiliconLabs/SimplicityStudio/v4/developer/sdks/gecko_sdk_suite/v2.7/platform/base/hal/micro/cortexm3/efm32/gcc-cfg1.ld", then modify the file gcc-cfg1.ld:

MFB_BOTTOM          = 0x00000000;   ---> change to 0x80000
MFB_TOP             = MFB_BOTTOM + FLASH_SIZE - 1;

Then build it and flash the generated image into the kit.

5.3. Add a Custom Command to Switch

In both the applications, add a custom command "custom test <area>" to switch between the two applications. The source code is:

void custom_test_cmd()
{
	uint8_t area = emberUnsignedCommandArgument(0);

	if (0 == area) {
		halInternalSysReset(0xDCBA);
	} else {
		halInternalSysReset(0xABCD);
	}
}

EmberCommandEntry emberAfCustomCommands[] = {
    emberCommandEntryAction("test", custom_test_cmd, "u", ""),
    emberCommandEntryTerminator()
};

5.4. Modify the Bootloader to Bootload Application According to Reset Cause

In bootloader, modify the source file "btl_main.c".

1. Remove the "const" attribute of the global variable "mainStageTable".
2. Modify the function SystemInit2. Find the source code started with "add by jim".

   /**
    * This function gets executed before ANYTHING got initialized.
   * So, no using global variables here!
   */
   void SystemInit2(void)
   {
     // Initialize debug before first debug print
     BTL_DEBUG_INIT();
   
     // Assumption: We should enter the app
     bool enterApp = true;
     // Assumption: The app should be verified
     bool verifyApp = true;
   
     // Check if we came from EM4. If any other bit than the EM4 bit it set, we
     // can't know whether this was really an EM4 reset, and we need to do further
     // checking.
   #if defined(RMU_RSTCAUSE_EM4RST) && defined(APPLICATION_VERIFICATION_SKIP_EM4_RST)
     if (RMU->RSTCAUSE == RMU_RSTCAUSE_EM4RST) {
       // We came from EM4, app doesn't need to be verified
       verifyApp = false;
     } else if (enterBootloader()) {
       // We want to enter the bootloader, app doesn't need to be verified
       enterApp = false;
       verifyApp = false;
     }
   #else
     if (enterBootloader()) {
       // We want to enter the bootloader, app doesn't need to be verified
       enterApp = false;
       verifyApp = false;
     }
   #endif
   
     //add by jim
     // *INDENT-OFF*
     #if defined(EMU_RSTCAUSE_SYSREQ)
       if (EMU->RSTCAUSE & EMU_RSTCAUSE_SYSREQ) {
     #else
       if (RMU->RSTCAUSE & RMU_RSTCAUSE_SYSREQRST) {
     #endif
         if (0xABCD == reset_classifyReset()) {
           mainStageTable.startOfAppSpace = (BareBootTable_t *)(0x80000);
         } else {
           mainStageTable.startOfAppSpace = (BareBootTable_t *)(0x0);
         }
       }
     //end add
   
   
     uint32_t startOfAppSpace = (uint32_t)mainStageTable.startOfAppSpace;
   
     // Sanity check application program counter
     uint32_t pc = *(uint32_t *)(startOfAppSpace + 4);
     if (pc == 0xFFFFFFFF) {
       // Sanity check failed; enter the bootloader
       reset_setResetReason(BOOTLOADER_RESET_REASON_BADAPP);
       enterApp = false;
       verifyApp = false;
     }
   
     // App should be verified
     if (verifyApp) {
       // If app verification fails, enter bootloader instead
       enterApp = bootload_verifyApplication(startOfAppSpace);
       if (!enterApp) {
         reset_setResetReason(BOOTLOADER_RESET_REASON_BADAPP);
       }
     }
   
     if (enterApp) {
       BTL_DEBUG_PRINTLN("Enter app");
       BTL_DEBUG_PRINT_LF();
   #if defined(BOOTLOADER_WRITE_DISABLE)
       lockBootloaderArea();
   #endif
   
   #if defined(BOOTLOADER_ENFORCE_SECURE_BOOT) && defined(APPLICATION_WRITE_DISABLE)
       // The neccessary check of valid signature pointer for application at startOfAppSpace
       // is already done in bootload_verifyApplication.
       bootload_lockApplicationArea(startOfAppSpace, 0);
   #endif
   
       // Set vector table to application's table
       SCB->VTOR = startOfAppSpace;
   
       bootToApp(startOfAppSpace);
     }
     // Enter bootloader
   }

6. How It Works

• Flash bootloader
• Flash the built image of zigbee_minimal_soc_0_mg12
• Flash the built image of zigbee_minimal_soc_1_mg12

By default, the bootloader will bootload the application "zigbee_minimal_soc_0_mg12". When the application starts up, you can use the following command to switch between the applications.

custom test 0  -- switch to application in area 0
custom test 1  -- switch to application in area 1

7. .sls Projects Used

Project	Comment
bootloader_storage_internal_single_mg12.sls	Bootload application in area 0 or 1 according to the reset cause
zigbee_minimal_soc_0_mg12.sls	Application runs in area 0 (0x0 ~ 0x80000)
zigbee_minimal_soc_1_mg12.sls	Application runs in area 1 (0x80000 ~ 0x100000)

8. How to Port to Another Part

This example can be used on any parts with 1MB flash. Below are the steps of porting it to other part:

• Import the .sls file into Simplicity Studio
• Open the .isc file of each project, turn to "General" tab, hit button "Edit Architecture", then select the board and part.

9. Special Notes

If you regenerate your project, you need to check and configure the symbol FLASH_SZE again.