Vector forwarding

RE: Vector forwarding

Hung Bui — Mon, 15 Jan 2024 08:56:29 GMT

Hi Erik,
The code of MBR is not published and we generally dont give information about how the code is implemented. But as far as I know it doesn't use VTOR to forward the interrupt.
Do you have any special requirement that you want to know more about the MBR ?
Our suggestion is to follow what we have in the bootloader if you want to do something more advanced.

RE: Vector forwarding

Erik Friesen — Fri, 12 Jan 2024 23:17:02 GMT

I'd like to let the softdevice handle the process, but the mbr is a closed box and I can't understand how it is forwarding interrupts. As stated above, its apparently doing something special because changing the vector makes it crash.

RE: Vector forwarding

Hung Bui — Fri, 12 Jan 2024 14:15:22 GMT

Hi Erik,

Please correct me if I'm wrong, but you want to have your own bootloader and you want to jump to the application after the bootloader. But you don't want to use the softdevice to jump to the bootloader but rather forward the interrupt manually and jump directly from the bootloader ?

I assume you have studied our bootloader ?

I think you can consider using sd_mbr_command_irq_forward_address_set_t to forward the interrupt to the application vector table and then jump after that.
You would need to make sure you de-init the softdevice before doing so if you already initialize it in the bootloader. You do so by a soft reset then boot back to the bootloader then jump to the application. In your application you would need to initialize the softdevice. Think of using your application as the 2nd stage bootloader.

Could you let me know why you don't want to jump to 0x1000 and let the softdevice handles the process ?

RE: Vector forwarding

Erik Friesen — Fri, 12 Jan 2024 03:29:51 GMT

I can't seem to edit, but I used it like this

SCB->VTOR = 0x1000;