Bootloader LPC1768 - Issues

If I understand you correctly, your application at 0x2000 only runs if activated from your boot loader. Not when you instead tries to get the debugger to directly start execution at 0x2000.

The question then - what startup code does the application have? And what startup code does the boot loader have?

A direct jump to 0x2000 from the debugger means that you haven't run the code from the startup file of the boot loader which might do something that your main application forgets to do. Who is remapping the interrupt vector table into RAM?

If I understand you correctly, your application at 0x2000 only runs if activated from your boot loader. Not when you instead tries to get the debugger to directly start execution at 0x2000.

The question then - what startup code does the application have? And what startup code does the boot loader have?

A direct jump to 0x2000 from the debugger means that you haven't run the code from the startup file of the boot loader which might do something that your main application forgets to do. Who is remapping the interrupt vector table into RAM?

At 0x0000

<prev>
#include "type.h"
#include "LPC17xx.H"

#define USER_FLASH_START 0x00002000

void execute_user_code(void)
{ void (*user_code_entry)(void);

SCB->VTOR = USER_FLASH_START; user_code_entry = (void (*)(void))((USER_FLASH_START)+1); user_code_entry();
}

int main(void)
{

SystemInit(); execute_user_code(); // call while(1);
} </prev>

It's run perfectly. Note that each Keil project I have separated files to manipulate :
lpc17xx.h, core_cm3.h, system_lpc17xx.c, startup_lpc17xx.s (I use folders named /common/src and /common/inc under the /source folder)

Yesterday, I change a system_lpc17xx.c of my application (that runs at 0x2000). I put at end of this file the following code
<prev>
// Set Vector table offset value
#if (__RAM_MODE__==1) SCB->VTOR = 0x10000000 & 0x3FFFFF80;
#else SCB->VTOR = USER_FLASH_ADDRESS & 0x3FFFFF80;
// SCB->VTOR = 0x00000000 & 0x3FFFFF80;
#endif
</prev>

and

on Lpc17xx.h

<prev>
#define USER_FLASH_ADDRESS 0x00002000
</prev>

After that debug runs ok, but there are a curious flash data written on
<prev>
0x0000001C 0007 MOVS r7,r0
0x0000001E 0000 MOVS r0,r0
</prev> I've noted this on disassembly window. I am searching for the reason.

Any help ?

At 0x0000, i wrote a simple application

#include "type.h"
#include "LPC17xx.H"

#define USER_FLASH_START 0x00002000

void execute_user_code(void)
{ void (*user_code_entry)(void);

SCB->VTOR = USER_FLASH_START; user_code_entry = (void (*)(void))((USER_FLASH_START)+1); user_code_entry();
}

int main(void)
{

SystemInit();
execute_user_code(); // call
while(1);

}

It's run perfectly. Note that each Keil project I have separated files to manipulate :
lpc17xx.h, core_cm3.h, system_lpc17xx.c, startup_lpc17xx.s (I use folders named /common/src and /common/inc under the /source folder)

Yesterday, I change a system_lpc17xx.c of my application (that runs at 0x2000). I put at end of this file the following code

// Set Vector table offset value
#if (__RAM_MODE__==1) // <--- i didn't discover the definition on project yet !!!
SCB->VTOR = 0x10000000 & 0x3FFFFF80;
#else
SCB->VTOR = USER_FLASH_ADDRESS; // change the vector to desired address
// SCB->VTOR = 0x00000000 & 0x3FFFFF80;
#endif

and

on Lpc17xx.h

#define USER_FLASH_ADDRESS 0x00002000

After that debug runs ok, but there are a curious flash data written on

0x0000001C 0007 MOVS r7,r0
0x0000001E 0000 MOVS r0,r0

I've noted this on disassembly window. I am searching for the reason.

Any help ?

Hi,

have you looked at the application note of NXP?
It explains well how to make the bootloader with the LPC1768.

ics.nxp.com/.../an10866.zip

good luck.