If you're doing functional safety likely going to need to understand MCU and surrounding tools, and implement your own methods.
S19 with be Motorola HEX format. Tools like SRecords exist, but the formats are not particularly complicated. This and object files should be covered at college level.
I think SRecords has CRC / Checksum options, IAR tool chain had some too. Don't use STM8/Cosmic so don't know specifics, would imagine there's docs and tutorials. Materials don't have to be tool specific if done as a post-link, user or batch file step.
If you can read memory via a pointer you should be able to implement target side code to sum, or CRC that content, and confirm integrity. ie data built on host matches materials running on target.
Writing packaging and signing tools should be with the scope of team responsibilities.
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