2nd stage bootloader
Hi,
How can I implement a 2nd stage bootloader with my firmware ?
I want that the 1st stage bootstrap check my firmware with checksum and start the firmware. If the checksum incorrect then the bootstrap should jump into boot mode.
Br,
Rainer
Andreas Jacob
Hilscher Gesellschaft fuer Systemautomation mbH
Hi Rainer,
this is already implemented in zhe existing 1st stage bootloader of the chip.
The Bootloader checks the image if it is valid (also with a checksum). If the image is valid it will be started.
If the image is corrupted, the first stage bootloader check all the other possible sources for an image and will stop in the mode which is set to the RDY/RUN pins.
For example: You set to the RDY*/RUN pins the extension bootmode and the 1st stage bootloader detect, that the image inside of the flash is corrupted, he will jump to the other sources, there is also no valid boot image so he will stop in the extension boot mode, which will give you an access to the chip over serial or USB port.