Bootloader

Kernel
1

betete wrote on Thursday, March 04, 2010:

Hi. I’m working with LPC2368 and Freertos. My application is working fine. Now I need to implement a bootloader to upgrade the firmware from external flash memory (SPI). The first thing I did to test was to write a very simple bootloader that jumps to address 0x1000 (where user application should be). Then I move the application code so that its entry point is 0x1000. I did that by modifying the memory map, setting flash starting address at 0x1000. The application compiled ok, and was loaded at 0x1000. The problem is that it keeps reseting. I followed the code step by step, and the problem seems to be in function:
void vPortISRStartFirstTask( void )
{
/* Simply start the scheduler.  This is included here as it can only be
called from ARM mode. */
portRESTORE_CONTEXT();
}

when the call to portRESTORE_CONTEXT() is made, the application restarts.

Any idea how to make this work?

Thanks.

2

edwards3 wrote on Thursday, March 04, 2010:

Check that the LPC is in Supervisor mode before portRESTORE_CONTEXT() is called. It will crash on that function if it is not.

3

betete wrote on Friday, March 05, 2010:

Thanks for your reply. The processor is in Supervisor Mode befor portRESTORE_CONTEXT() is called. Actually, crt0.s makes the processor switch to supervisor mode befor the main application is called.

4

preetpal wrote on Tuesday, March 09, 2010:

FreeRTOS should be independent of flash offset defined by your application.  I am using secondary bootloader for LPC2148 and it is working just fine.  Try running an application without FreeRTOS, if that works, then there’s no reason why FreeRTOS shouldn’t.

5

ruggerobandera wrote on Friday, October 21, 2016:

I’m using FreeRTOS V8.2.3 and a STM32746G with the discovery board.
I create a simple FreeRTOS application and all works fine. Now I create a Simple Bootloader (no RTOS) The Simple Bootloader is mapped ta 0x08000000 my Application is mapped 0x08010000.
After the jump below the code I used

typedef void (*p_function)(void);
// address == 0x08010000.
void JmpToAddress(unsigned int address)
{
    uint8_t i;
    uint32_t jump_address = *(__IO uint32_t*)(address + 4);
    p_function p_jump_function = (p_function)jump_address;
    __disable_irq(); // stop all interrupts
    // Disable IRQs
    for(i = 0;i < 8;i++)  {
        NVIC->ICER[i] = 0xFFFFFFFF;
    }
    // Clear pending IRQs
    for(i = 0;i < 8;i++)  {
        NVIC->ICPR[i] = 0xFFFFFFFF;
    }

    __enable_irq();
    __set_CONTROL(0);
    // re-init stack pointer (first entry of the vector table)
    __set_MSP(*(__IO uint32_t*)address);

   p_jump_function();
}

my application start correctly RTOS create theall the tasks and jump to the firsttask.
My code is

firsttask(void const * argument)
{
   kernelStatus = osKernelRunning();// status is ok
	
	for( ;; ) {
		// do somethings ...
		OSIDelay(200); //never exit
	}
}

It Seem’s as the scheduler dosen’t run.
Any Idea

6

rtel wrote on Friday, October 21, 2016:

This is a very old thread, and without knowing what happens at the address you are jumping to it is difficult to know.

You need to have a vector table set up for the application you are jumping to, set the vector base address register to that vector table, and make sure the FreeRTOS interrupt handlers (PendSV, SysTick and SVCall) handlers are installed in the vector table. I would then recommend leaving interrupts globally disabled, reading the reset address out of the second position of the vector table used by the application you are jumping to, and jumping to that address to ensure the C run time code is also executed before main().