Firmware Update Example

Matthias Kassner said:

Hi Lori,

thanks for the pointer, that is very interesting!

Ideally, the customer would like to have full SW control over the process, i.e. not use Boot ROM code.

This would allow them to handle time-critical interrupts during the process.

Would we have an example for that?

Best regards,

Matthias

Matthias,

We don't have exactly what you ask for.  Some ideas on how to implement this:

Option 1:

Create a custom boot loader and flash it into the OTP.  This can be the same as what is in the boot ROM with some additional functionality.   Then instead of "boot to SCI" you would "boot to OTP".   Note in this case, the kernel + flash API would still be downloaded from the SCI just like the boot ROM does - you are just adding additional functionality.

Here is an application note that talks about creating a custom boot loader for OTP - the example is for eCAN or SPI.  The idea, however, is the same for SCI.

Option 2:

Have the kernel + flash API stored in flash along with the application code.  When a re-flash is started, the code copies the kernel + flash API to RAM along with any interrupts to be serviced (everything has to run from RAM while flashing takes place).   Then call the kernel which talks with the SCI just like in the application note.

Note:

The API does block interrupts during time critical portions of code.  The longest is during the erase operation where interrupts are blocked for 3-4ms.

-Lori