I use LPC1768 for a project that contains many properties like Usb BootLoading. For this, i've tried to use "USB Secondary Bootloader". It works really good. (i've added CRC) But in my project, i have to use software selectable jump task. Not EntryPin using. i'm not good at assembler. just lil bit. i use USB Sec. Bootloader's BOOT JUMP method's opposite. (and changed some things of course) But wasn't able to resolve jumping problem. i gave HArdFault on user program side.
My last chance is changing the ROM image's CRC intentionally. And then reset MCU. After this bootloader can automaticly run due to bad checksum :)
But this is not so suitable for me. Is there any method for this.? Many Thanks
Babur
Does your system have any non-volatile memory? EEPROM maybe? You could also use a Flash register from the on-chip Flash as a dedicated switch variable.
You could use IAP to read write to this Flash register.
Hi Marc. Yes i have one 24C series. Also i can write, MCU's ROM section easily. :) But both of them requires Big Part of image. (4K) Yes it's possible to Fill some area with specific value. But this is not suitable for me. Maybe last chance. i think i will change the CRC to bad one. just this can tell that "something went wrong" to my bootloader software. Any idea?
Many Thanks Babür