I use a free, open-source cross assembler - "SB-Assembler 3" written in Python by San Bergmans whose electronics hobby website is
https://www.sbprojects.net
It can be downloaded from there. A beta version of it was shown being used in this rather shonky Youtube video of mine posted several yours ago now. It didn't include a 'Cross' for the 8060/SC/MP at that time so I had to write that bit myself, and I only did the absolute minimum required to make it work.
https://www.youtube.com/watch?v=j1WSy_ueX34
SB-Assembler 3 has since made it to the final release version which includes an 8060 / SC/MP 'cross' file properly written to the same standard as the rest by San himself. As it's written in Python it will run on any platform for which Python is available, including, as seen above, on a Raspberry Pi.