Just a brief heads-up for anybody who might be interested. I have added official support for running Zephyr RTOS on the ARM Cortex-M1 DesignStart FPGA reference design:
Both the Cortex-M1 and Cortex-M3 ARM DesignStart FPGA Xilinx Edition reference designs are now supported by Zephyr RTOS. I have also added support for the V2C-DAPLink shield: https://docs.zephyrproject.org/latest/boards/shields/v2c_daplink/doc/index.html
Support is available on current development branch and will be part of Zephyr RTOS v2.4.