Setting PIC18F8722 Bootloader size

[ktallevi]

I noticed there is no #fuse to set the bootloader block size. CONFIG4L:BBSIZ bit.

I need to have a bootloader of 8k in size and protected. I see you can protect the bootloader but not set the size via fuses.

anyone have any suggestions? thanks

-kevin

[jma_1]

Greetings,

If you use the CCS bootloader example, you can set the protected area size. I have not done this, but it appears you could modify LOADER_SIZE to suit your needs.

Why do you need 8k worth of reserved space? Are you trying to put a test application into the boot blocK? Is there enough space left over for your real application? If you are just trying to maintain data, can you use the EEPROM? These are just questions, but perhaps there might not be a need to reserve such a large amount of bootloader space.

Cheers,
JMA

[ktallevi]

The PIC18f8722 has more than enough room for my application outside of the bootloader.

My bootloader will work over multiple interfaces so I require code to configure those external interfaces. I may not require 8k by the time I optimize my code.

Anyways, setting the boot block size using config words is required. I am just not sure how to do it. I could use a bit-set assembly routine but that occurs at run-time only.

Perhaps a modification to 18F8722.h is required to set the CONFIG4L:BBSIZ bit?

[jma_1]

Greetings,

After looking at the 18F8722, there is tons of space available.

I do not understand your need to use the configuration bits to set your protected boot block size. If you compile your application source code with the space set aside, your application does not overwrite the boot block. Please explain further why you want to use the configuration bits.


Cheers,
JMA

[ktallevi]

by using the configuration bits to set the bootloader size, it protects against any accidental writes to the bootloader area while the device is in the field.

which the chances of that are slim, it is possible.

[PCM programmer]