rewrite bootlosder

[ybitton]

Posted on May 29, 2011 at 14:02

Hi,

I need to add a decryption mechanism to the bootloader firmware.

1. Is it possible to wirte a new bootloader firmware to ''system memory'' adreess 0x1FFF F000 - 0x1FFF F7FF (instead of the existing one)?

2. Can i get the bootloader firmware wich ST deliver (my micro is STM32F100RB)?

    or should i rewrite a new one?

Thanks.

#bootloader #bootloader

[Tesla DeLorean]

Posted on May 30, 2011 at 03:52

It's in ROM so it might be a tad hard to rewrite/replace, and it's pretty tightly packed in 2KB. I have an annotated listing of the 103 boot rom. The Readout Protection is enforced, so your code is protected from your casual user.

As I recall some of the ST DFU loaders use AES

My general recommendation would be to write something simple, based on the XMODEM, or family of protocols. Simple and robust.

Not sure what encryption you have in mind, or if it is worth the effort. Without a strong end-to-end chain of protection, most of these things are breakable, or built broken. What's to stop someone extracting firmware from the die?

[ybitton]

Posted on May 30, 2011 at 14:31

Thanks clive1,

Can you share with me (us) the boot rom annotated listing that you have (to be used as a reference)?

[ybitton]

Posted on May 30, 2011 at 14:33

Can you share with me (us) the boot rom annotated listing that you have (to be used as a reference)?

[Tesla DeLorean]

Posted on May 31, 2011 at 15:15

https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=%2Fpublic%2FSTe2ecommunities%2Fmcu%2FLists%2Fcortex_mx_stm32%2FSource%20Code%20for%20STM32%20bootloader&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=478

[DEAD LINK /public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Source Code for STM32 bootloader&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=478]Flat.aspx