bootloader / rev a/b/z double check

[john]

Posted on April 15, 2008 at 09:48

bootloader / rev a/b/z double check

[john]

Posted on May 17, 2011 at 12:30Hi, When I'm using a dev. board from Keil (MCBSTM32) with CPU: ARM B... the PC bootloader (new version 2.0) works just fine, at all bauds... So I am happy that the system works on my PC with cables... We have our own development board on which we have a CPU that was obtained as a 'free sample' (from EBV) back in Jan 08 (or even Dec 07). On this board, when we enter the bootloader and connect from the PC, it starts OK :- pc sends: 0x7f arm sends: 0x79 pc sends: 00 FF no reply from arm ! The Arm chip was a STM32F101T6U6. Note - please don't ask for the labeling of the chip, as we've sent it off to a customer. Q.1) what are the chances of that 'free sample' chip not having a bootloader in it that is compatible with the new PC 2.0 application ? We are about to build our next version of our boards, and the Arm chips are labeled :- stm32f101t6u6 9ydrl 93my6 744 e3 Z NB. as best I can read. Q.2) what are the chances of this chip having a bootloader in it that is compatible with the new PC 2.0 application ? OR - would anyone have any suggestions as to why our first dev board did not work with the bootloader ? And would our newer chip have a better chance of working ? Thanks, John.

[lanchon]

Posted on May 17, 2011 at 12:30

I think I remember some early chips had a different bootloader version. I suspect the loader is a factory-programmed flash, so there needn't be a strict 1-to-1 relation between silicon rev and loader ver.

I'd advice everyone who is relying on the bootloader to check the bootloader version after reset with a hash, CRC or checksum, and refuse to run the app if there's a mismatch. this will ensure that all boards that pass testing have the expected bootloader. if ST changes the loader you'll have a chance to validate the new loader or think of what to do before shipping the product.

[john]

Posted on May 17, 2011 at 12:30Our situation is that we are having boards made up, and we will need to program the chips a first time. We have no code in the chip to start with - so we have to use the bootloader (which is what its intended for, I assume). These boards are a production test batch, so we can do them all by hand (maybe in mass production we can have an image loaded onto the chip before assembly ?). For these 'newer' chips, I'm quite confident that the bootloader will work - but thats not tested and verified yet. For the couple of dev. boards we have with the older CPU's on them, they may well have an older version of the bootloader code in them. Where might I find all the different versions of the PC bootloader app ? I'd like to try out any other/older versions of the PC app with the older chips. Thanks, John.