My own bootloader for STM32H750, is this possible?

[andre239955_st]

Hi,

We have devellopped our own bootloader for the different families of STM32. This is based in one sector of the flash while it is able to reprogram the other sectors. Now I am working with a STM32H750 but this one has only 1 sector... I might already know the answer but I would like confirmation, can I use my own booloader here?

If not, what means do I have for reprogramming a device with its read protection activated?

Thanks,

André

[Alex R]

@andre239955_st​ : Is the upgrade to be done in the field ( for 1 Million devices?)? How ofter you expect this to happen? Or it is only at manufacturing (or Service) time?

Maybe the chance to lose power during the upgrade is very low, and therefore, running the bootloader from RAM wouldn't be an issue.

[andre239955_st]

@Alex R: We don't upgrade like an IoT device, it has to be done by one of our field technicians (safety products). But in production it is a different story; a change of version implies a fast reprogramming of the stock. That number is limited normally to 1K.

I agree, it doesn't happen often that a power loss occurs so for this project I could take the risk.

But I am curious to see the secure bootloader from ST. Hopefully I don' have to rewrite it because we don't use HAL.

[MikeDB]

I'm using the H750 and have a similar problem so very interested in this thread. One question I will ask is are you sure you can get 1 million H750s ? They are around but only in the tens of thousands.

[Tesla DeLorean]

Well ST isn't going to build them speculatively, most everything is built to order, fab time minimum of 12 weeks, and people buying a million pieces have planners, and submit plans to ST for staggered delivery, and non cancellable orders. Distributors hold about zero stock of anything these days.

Best guess on the H7 front is the die is being spun again to nail down whatever dual core and DSI issues still remain.

[MikeDB]

Dual core issues ? H750 is single core.

I did a search a few weeks back and whilst US stocks do seem very low and European stocks number about 1000, there do seem to be around 10k units available in China. Oh and several hundred units on a Russian website 🙂

[andre239955_st]

Hi mbryant,

These 1 million is all our products together. But this project is meant to replace a product which we sell at 10K pieces a month. So yes, we can get that amount of microcontrollers from ST, we never had any issues for delivery.

[Uwe Bonnes]

You should also get in touch with your FAE. The number of 1 million of chips should make them interested and helpfull.

[MikeDB]

Actually since the H750 is (currently I admit) just a not fully tested H743, at the volumes you are talking about they might be prepared to create a H751(?) with two sectors of flash tested. Slightly more expensive as test time is longer but cheaper than adding an external QSPI/

I think others might be interested in a 2 sector product as well if you need to convince the FAE to ask HQ.

[Uwe Bonnes]

And when you are at it: Please try to convince them to make a H740. Export regulation on H750 will be a PITA.

[MikeDB]

Interestingly the ones I bought from Avnet Europe came with several pages of regs on export. The ones from China came with nothing. I haven't ordered any from Russia but the fact they are on open sale there shows the regs are a nonsense.

But yes a H741 with 2 sectors and no encryption is probably even better for everybody.