To to get a simple STM32CubeIDE application to work with this?
I'm using an STM32F103C8 Bluepill with this bootloader and I can install, say, QMK keyboard firmware over USB and it works: first I flash the bootloader and then I install the QMK firmware over USB (using dfu-util); then, when I connect the Bluepill over USB and run lsusb (on a loop), for a couple of seconds I can see Leaflabs Maple DFU interface as a USB device, and then the QMK firmware takes over.
However, when I try to install a simple STM32CubeIDE USB HID application over USB, I can install it but it never runs: lsusb shows Leaflabs Maple DFU interface always and my firmware never takes over.
(However, the same application does work/run when I flash it directly to the STM32.)
How can I get it to work? Maybe I need to modify the linker script somehow to put things in places that this bootloader expects?