Support for ST-LINKV3MINIE hardware

[eflukx]

Would it be possible to support the ST-LINKV3MINIE hardware? It also employs a STM32F723 and is readily available globally at a competitive price.

[Yatekii]

It is supported - if anything the USB VID/PID have to be added :)
While ST-Link is very cheap and nice HW, the Software makes up for it and is not open source, locked to STM32's and orthogonal to all other probe APIs.
So I always recommend other probes.

edit: I thought this is the probe-rs repo - sorry.

[korken89]

@Yatekii I don't think the HS probe has a BSP nor support for the level translators on the ST-LinkV3MINIE.

@eflukx This could probably be added, but it would require someone with interest to get the schematics for the STLink and port the code to this hardware.
I've not checked if the schematics are open, but it should be quite doable if they are.

[Yatekii]

Ah lol, I am stupid, I am sorry, somehow I thought this is the probe-rs repo 🤦

[Disasm]

From the firmware point of view supporting this hardware is technically possible and should not be very difficult, however, uploading this firmware to the hardware may not be possible. Some time ago ST updated the bootloader in v3 stlinks and now some sort of a cryptographic signature is used to check the uploaded firmware. Old stlinkv3 devices use the old bootloader though, which doesn't check the uploaded firmware. For these devices it's possible to upload custom firmware.

[korken89]

Thanks for the insight! One can't access the debug port either I guess?

[Disasm]

Starting from version V3J6M2 (~Jan 2020) firmware enables Level2 protection which permanently disables the debug port.

[korken89]

Oof, well that was unfortunate... for us 😅

[eflukx]

Starting from version V3J6M2 (~Jan 2020) firmware enables Level2 protection which permanently disables the debug port.

Hmm.. that is kind of crappy... The STLINK's seemed a really good option given their general availability and price.
What I'm struggling with is that the STLINKV3 does not support the Nordic devices (which I typically use) and also hard-chokes (as a "feature") on non-genuine "STM32" clones.
An open firmware on these devices would really be nice.. oh well... you can't win them all...

Ps. And I guess the DFU way is also closed (by cryptographic means..) as mentioned by @Disasm

Off topic: what would be the probe-of-choice:tm: to use with probe-rs. I'm currently using JLink devices, but I'm not really impressed by the performance of these (in conjunction with probe-rs anyway)...

[Yatekii]

We have two open source probes (you can find the repos in the org) that @korken89 designed and we just started another production batch :) We sell it basically at cost on our webpage. But you can ofc assemble it yourself :)

[Disasm]

An open firmware on these devices would really be nice.. oh well... you can't win them all...

There is still hope. IIRC new firmware can still be decrypted, so one day someone may find a code execution vulnerability which may allow bootloader dumping and it may happen that crypto used for integrity checks is so custom that it can be broken easily by looking at the bootloader code.
When someone reported that a new bootloader is now shipped with new stlinks, I ordered a couple of probes directly from ST and unfortunately they all had the old bootloader :)

Ps. And I guess the DFU way is also closed (by cryptographic means..) as mentioned by @Disasm

Original DFU located in system memory is disabled due to Level2 protection and does not support USB HS peripheral which is connected to the USB connector. For the update purpose ST flashed their own DFU-like bootloader which decrypts the firmware to update and (depending on the version) performs integrity checks.