How to start an application from bootloader at specified address?

[Alex Pristenskiy]

Hello.

I use s130 2.0.0-7.alpha stack and thus app starts at 0x1B000

Questions:

1. How to change default app start address, for example to 0x25000 ?

2. How to programmatically switch between 2 apps from bootloader, one app at 0x1B000 and another at 0x25000 (~40 Kb each) ?

3. I see the following lines in bootloader example:

   if (bootloader_app_is_valid(DFU_BANK_0_REGION_START) && !bootloader_dfu_sd_in_progress()) { // Select a bank region to use as application region. // @note: Only applications running from DFU_BANK_0_REGION_START is supported. bootloader_app_start(DFU_BANK_0_REGION_START); }

does it mean that bootloader can start only app at 0x1B000 address?

does it mean that after download update to 0x25000 it's only possible to copy it to 0x1B000 and then start?

Thanks!

[Fabien Comte]

Hello,

You could try to replace DFU_BANK_0_REGION_START by a variable called my_app_address.

unsigned int my_app_address;
if (condition)
{
   my_app_address = DFU_BANK_0_REGION_START;
}
else
{
   my_app_address = SECONDARY_ADDRESS;
}

if (bootloader_app_is_valid(my_app_address) && !bootloader_dfu_sd_in_progress())
{
   bootloader_app_start(my_app_address);
}

Each application should be compiled with the right ld file (ORIGIN is modified)

[Alex Pristenskiy]

Thanks. The main question is what should be a value of SECONDARY_ADDRESS ? Because DFU_BANK_0_REGION_START is not equal to 0x1B000 So, SECONDARY_ADDRESS with a value 0x25000 doesn't work.

[Alex Pristenskiy]

Actually my minimal wish is to run app from bootloader: devzone.nordicsemi.com/.../

[Fabien Comte]

Secondary address is what you need (for me it's 0x00049000). I think in the case of nRF5x slots are not an hardware limitation but user chosen areas that fit with your need. Some adresses are fixed (SD memory model in documentation) but not the start of application if you have a bootloader.