Looking for CC2531 SBL Sniffer firmware

[pvermeij]

After purchasing a ZZH stick my CC2531 stick isn't used anymore so I want to use it for sniffing Zigbee traffic.
To do so I need to replace the firmware with sniffer firmware but can only find firmware which need to be flashed with a CC-Debugger. As I don't own a CC-Debugger but use SerialBootTool to flash the CC2531 stick I'm looking for CC2531 SBL sniffer firmware.

I've allready tried to convert 'zboss_sniffer.hex' to a bin file using objcopy.exe --gap-fill 0xFF --pad-to 0x040000 -I ihex zboss_sniffer.hex -O binary zboss_sniffer.bin but flashing the bin file to the stick results in an error.

Is there a way to create a SBL version of the ZBoss sniffer firmware?