Add 32kb offset option for STM32H750

[wildBill83]

The offset option was missing in kmake of the STM tree. Tested and working great on my STM32H750

Signed-off-by: Bill Horan whoran83@gmail.com

[asnajder]

Can confirm it is working on my Sovol Zero, which uses the STM32H750 (edit: after correctly re-flashing Katapult, and then in my case, Klipper)

[wildBill83]

Others are trying to add a 128kb offset similar to other STM32H7 chips but the H750 variant is only 128kb, I believe this is why subsequent flash errors are happening from DFU mode from prior attempts.

[Arksine]

Thanks. As mentioned in the cross linked Klipper PR, the Pull Request needs to be signed off for acceptance of the DCO.

Previously when I attempted to enable support for the STM32H750 the user who tested it reported a failure, but it certainly now appears it was because the H750 only has 128KiB of flash. If someone who has tested these changes could post a screenshot of their terminal demonstrating a successful attempt at using Katapult to flash Klipper it would be appreciated.

[asnajder]

Hey @Arksine , here's a screenshot of me re-flashing Klipper on my stm32h750:

Note, when I originally flashed Katapult using my ST-LINK, I used a different method, unfortunately no screenshots of that, but I did document the process:

1. Flashed @wildBill83 's stm32h750_katapult.bin he provided for testing using ST-LINK
2. Upon boot, I verified with ls /dev/serial/by-id, and saw usb-katapult_stm32h750xx_1C0027000651333233353131-if00
3. Stopped Klipper, flashed using this method: python3 ~/katapult/scripts/flashtool.py -f ~/klipper/out/klipper.bin -d /dev/serial/by-id/usb-katapult_stm32h750xx_1C0027000651333233353131-if00
4. Using lsusb, I saw: Bus 008 Device 003: ID 1d50:606f OpenMoko, Inc. Geschwister Schneider CAN adapter
5. Verified my can0 was up, and then got my new canbus ID for my printer.cfg:

python3 ~/katapult/scripts/flashtool.py -i can0 -q
Resetting all bootloader node IDs...
Checking for Katapult nodes...
Detected UUID: 07602842078e, Application: Klipper
Detected UUID: 6d8948ecb95c, Application: Klipper
Detected UUID: 916cc8e24db7, Application: Klipper
CANBus UUID Query Complete

Can confirm the above initial method worked, and can confirm via screenshot that future flashing still works.

[Arksine]

Thanks @asnajder, that screenshot is sufficient as it verifies that the H750 does indeed share the same flash logic as the H72x/H74x series. As soon as the OP adds his signature I will merge.

[matthew73210]

Just in case

sovol@sovol-zero:~$ python3 ~/katapult/scripts/flashtool.py -v \
  -f ~/klipper/out/klipper.bin \
  -d /dev/serial/by-id/usb-katapult_*
Connecting to Serial Device /dev/serial/by-id/usb-katapult_stm32h750xx_34001B001751333233393839-if00, baud 250000
Detected USB device running Katapult
Detected Klipper binary version v2026.03.00-0-g27902226-dirty-20260304_170326-sovol-zero, MCU: stm32h750xx
Attempting to connect to bootloader
Katapult Connected
Software Version: 7360fb4
Protocol Version: 1.1.0
Block Size: 64 bytes
Application Start: 0x8008000
MCU type: stm32h750xx
Flashing '/home/sovol/klipper/out/klipper.bin'...

[##################################################]

Write complete: 0 pages
Verifying (block count = 652)...

[##################################################]

Verification Complete: SHA = 444C6D1FB1B4339184A85A9EC2042BEB8F882CFB
Programming Complete

[wildBill83]

Thanks for the help and testing guys!

-wildBill83

[wildBill83]

Thanks. As mentioned in the cross linked Klipper PR, the Pull Request needs to be signed off for acceptance of the DCO.

Previously when I attempted to enable support for the STM32H750 the user who tested it reported a failure, but it certainly now appears it was because the H750 only has 128KiB of flash. If someone who has tested these changes could post a screenshot of their terminal demonstrating a successful attempt at using Katapult to flash Klipper it would be appreciated.

I have signed off in the initial message, let me know if you need anything else.

[Arksine]

Thanks.