topic Re: Kinetis relocated vector table program counter in Kinetis Microcontrollers

Kinetis relocated vector table program counter

ZdenoQC — Mon, 14 Sep 2015 13:23:02 GMT

Hi there,

I'm using a TRK-KEA128 evalboard and I have made a bootloader. Usually on S08/S12 family of microcontroller, I use the reset vector to start my application since this vector is not redirected. I was planning to do the same with the program counter with the Kinetis, but I don't know if a reset will cause the micro to restart directly at the application instead of the bootloader.

Ex:

Boot vector table

/* Interrupt vector table */

__attribute__ ((section (".isr_vector_boot"))) const tVectorTable __vect_table =

{ (uint32_t *) 0x1FFFF400, // 0x00 0x00000000 - Initial Stack Pointer

{

// ISR name num address source

(typ_ISRfunc) EntryPoint_Boot, // 0x01 0x00000004 - Initial Program Counter

...

Appl vector table

/* Interrupt vector table */

__attribute__ ((section (".isr_vector_appl"))) const tVectorTable __vect_table =

{ (uint32_t *) 0x1FFFF400, // 0x00 0x00004000 - Initial Stack Pointer

{

// ISR name num address source

(typ_ISRfunc) EntryPoint_Appl, // 0x01 0x00004004 - Initial Program Counter

...

I will than jump to address written in 0x00004004 when in boot to go to the application and than redirect the vector table.

My question, if I do that, when a reset occur, do the micro will restart in the boot or the appl?

Thanks

Re: Kinetis relocated vector table program counter

Jorge_Gonzalez — Tue, 15 Sep 2015 01:58:21 GMT

Hello William Deshaies:

After reset the KEA MCU always takes the entry point from flash address 0x00000004. For your case, after reset the MCU would always jump to EntryPoint_Boot and in the code there could be a decision to stay in bootloader or jump immediately to the application (e.g. by reading an external button).

In the startup of the application make sure to update the SCB_VTOR register to point to the application's vector table.

I hope this helps!

Regards!,
Jorge Gonzalez

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Re: Kinetis relocated vector table program counter

vignesh_vb_7 — Fri, 24 Feb 2017 15:20:59 GMT

Hi,

How do i do that In the startup of the application to update the SCB_VTOR, Can you give me a code snipet for this?

And if you can give an example code for blinky with changed linker file to be flashed with bootloader, it will be great?