Increase size of bootloader from 16KB to 20KB

ArduCopter Copter 3.6
1

I am trying to modify the bootloader, now it is exceeding the 16KB size, so to increase the size of the bootloader, I modified hwdwf.dat from “FLASH_BOOTLOADER_LOAD_KB 16” to “FLASH_BOOTLOADER_LOAD_KB 20”.

Now bootloader is getting complied sucessfully but when I am trying to build the complete firmware, I am getting following error:

[774/777] Generating bin/arducopter.bin
[775/777] apj_gen build/CubeBlack/bin/arducopter.bin
[776/777] Generating bin/arducopter.hex
Bad blimage size 16680

Please suggest the fix.

Thank you

2

I suggest you to use ArduCopter 4.0.7 as basis for your changes instead of 3.6.x

3

Thanks for your instruction. I updated this t4.0.7 but my build failed, I tied 4.0.6 and that worked, but still I saw same error in that version also.

Bad blimage size 16680

regards,
Zafar

4

You are constrained by the page layout on the supported stm32 chips when sizing your bootloader.

In particular, check FLASH_RESERVE_START_KB in the hwdef.

5

I also changed FLASH_BOOTLOADER_LOAD_KB to 20 from 16. I could build the bootloader but when I am trying to build the copter firmware, i am getting the same error mentioned above. This is happening because FLASH_RESERVE_START_KB is set to 16 by default for fmuv3. There is no FLASH_RESERVE_START_KB defined in hwdef.dat. Can you please help me proceed further. I have to get this done using Pixhawk1 only.