I am building a custom boot loader to work with out application on a custom board based on the UBLOX NINA-302 module. The boot loader will use USB as the only connection and that will use a USB driver we already developed for the application. The idea is to use a simple boot loader without a soft device or MBR that will interface directly to our host application over USB. The boot loader will start at 0x0 (FLASH_START=0x0) and a length of 0x10000 (FLASH_SIZE=0x10000). The application is built in SES with FLASH_START set to offset address (0x10000) and FLASH_SIZE set to 0x20000. The application was loaded into flash using J-Link before starting up the boot loader solution.
I am launching the application using the same funcitons that the Nordic boot loader wit some modifications specific to the implementation (files included below). I have tried this with the standard "start_app' with optimization and also by replacing the function with an updated version I found on the developer blog. The application seems to be starting up since I can track it using breakpoints up to "start_app" and then single set through the application code after the jump to the new reset handler. I can single step through code but hit a hard fault whenever I let it free run. The application has been stripped down to just blinky code with no interrupt service. I even stripped the boot loader down to just the launch code but the application still crashes. Any ideas?