problems with secondary bootloader on LPC1768 with MCP1700

You should check a CRC or equivalent prior to loading and attempting to run ANY code downloaded. Insofaras the code to re-startup the processor, this works on 1768:

void __SWI_0(void *(fp)())
{
        UINT32 RegTemp;

        // Reset PCONP to RESET conditions
        PCONP = 0x001817BE;

        // Restore VIC slots to RESET conditions
        UninstallIrq(SPI1_INT);

        __asm
        {
                MRS RegTemp, CPSR
                ORR RegTemp, RegTemp, #0xC0       // Only in supv mode - disable interrupts
                MSR CPSR_c, RegTemp
                MRS RegTemp, SPSR
                AND RegTemp, RegTemp, #0x1F       // Only in supv mode - set to RESET conditions
                MSR SPSR_cxsf, RegTemp
        }

        (*fp)();
}

Disable interrupts and jump to the start of program code. This sequence MUST be accomplished while the processor is in the 'Supervisory Mode' of operation so that the program stacks and restricted registers can all be accessed and properly initialized by the main program startup code when it executes. HTH.

You should check a CRC or equivalent prior to loading and attempting to run ANY code downloaded. Insofaras the code to re-startup the processor, this works on 1768:

void __SWI_0(void *(fp)())
{
        UINT32 RegTemp;

        // Reset PCONP to RESET conditions
        PCONP = 0x001817BE;

        // Restore VIC slots to RESET conditions
        UninstallIrq(SPI1_INT);

        __asm
        {
                MRS RegTemp, CPSR
                ORR RegTemp, RegTemp, #0xC0       // Only in supv mode - disable interrupts
                MSR CPSR_c, RegTemp
                MRS RegTemp, SPSR
                AND RegTemp, RegTemp, #0x1F       // Only in supv mode - set to RESET conditions
                MSR SPSR_cxsf, RegTemp
        }

        (*fp)();
}

Disable interrupts and jump to the start of program code. This sequence MUST be accomplished while the processor is in the 'Supervisory Mode' of operation so that the program stacks and restricted registers can all be accessed and properly initialized by the main program startup code when it executes. HTH.

Q S, Thanks for your quick answer.

As I'm transferring the application as S-record file, where every line has its own check-sum, as well as at the end there's an record where I can compare the count of received records with the ones contained in that s-record file.

I took from your code the PCONP reset, as I'm not using SPI/SSP interfaces I omitted the accesses to CPSR/SPSR.

It doesn't change very much. Very seldom the application starts, but most of the time not.

Now I took a deeper look what the processor does when jumping from bootloader into application.
Single-stepping (F11) in Disassembly beginning at my boot_jump function I observe the following:

After

LDR PC, [R0, #4]

the PC is at the Reset_Handler of the application, with single steps I walk through the SystemInit as well as the __main (_main_scatterload) from there I reach my normal main function. But the following free run (F5) results in a Hard_Fault (HARD_FAULT_STAT = 0x40000000)

I've already checked bit0 of the Interrupt vectors, they're all set (Thumb Mode).

What else am I missing?

Thanks Hubert

Digging even deeper into the assembly showed after reaching my main function

0x00021110 F7FEFFE9  BL.W     0x000200E6
0x00021114 2200      MOVS     r2,#0x00
0x00021114 2200      MOVS     r2,#0x00
0x00021116 4611      MOV      r1,r2
0x00021118 F2AF0057  ADR.W    r0,{pc}-0x53  ; @0x000210C5
0x0002111C F8DFC0C4  LDR.W    r12,[pc,#196]  ; @0x000211E4
0x00021120 DF00      SVC      0x00

executing the SVC 0x00 call results in the HardFaultHandler.

The C-code of that main look like

int main (void)
{
  os_sys_init(init);
  while(1);
}

I hope this gives some more hints about what I'm missing.

Thanks Hubert

Where do you remap your interrupt vectors for your new code into the proper interrupt offset prior to executing the os_sys_init(init) call? You need to go back and review how a system functions, I believe.

O.K.

Now I found the solution to start the application located at APPL_RUN_ADDR = 0x20000 reliably.

before changing the vector table the irq's have to be disabled in the bootloader.

__asm void boot_jump(U32 address)
{
    LDR SP, [R0]
    LDR PC, [R0, #4]
}

void run_appl()
{

//   void (*user_code_entry)(void);

   /* Change the Vector Table to the USER_FLASH_START
   in case the user application uses interrupts */

     __disable_irq();
     LPC_SC->PCONP = 0x001817BE;
     SCB->VTOR = APPL_RUN_ADDR & 0x1FFFF80;
     boot_jump(APPL_RUN_ADDR);
}

and in the application the irq's have to be enabled again before calling os_sys_init()!!!

int main (void)
{
  __enable_irq();
  os_sys_init(init);                        /* Initialize RTX and start init */
}

The bootloader is compiled with IROM1 Start=0x0 Size = 0x20000

The application is compiled with IROM1 Start=0x20000 Size = 0x60000 and Asm Define = NO_CRP

Hubert

Note that this works _only_ because your specific controller starts up in privileged mode. This might not be the case using other controllers.