"Mind you I also have a modified..." <- I'm a little late to this party but I'm working on similar things to you. Also trying to get slint working. Have you tried to use an external loader from ST and using their STM32CubeProgrammer CLI tool? This is the script I use to program my STM32H735G-DK that allows me to program the external NOR flash. I use attach RTT logs using the older probe-run instead of probe-rs because that tool formats the logs a little better: ```bash #!/bin/bash set -e cargo objcopy --bin ui --target=thumbv7em-none-eabihf --release -- -O ihex ui.hex $HOME/STMicroelectronics/STM32Cube/STM32CubeProgrammer/bin/STM32_Programmer_CLI -c port=SWD speed=fast -el $HOME/STMicroelectronics/STM32Cube/STM32CubeProgrammer/bin/ExternalLoader/MX25LM51245G_STM32H735G-DK.stldr -d ui.hex DEFMT_LOG=trace probe-run --chip STM32H735IGKx --no-flash ./target/thumbv7em-none-eabihf/release/ui ```