CV assistance - applying for interns

[StuffandFluff]

I am not sure whether this is the right place to post this for advice. Ds is currently second year uni and applying for internships for next summer. Whilst he has x3 A*s at A level, his GCSE results (Covid context) are not so good - including in his main uni subject. He took a year out before applying to university, during which he worked in a warehouse, to build up funds (so gained some transferable skills that can be included in his CV),
What is the protocol for CVs - is it fine to just detail the A levels, or will prospective employers expect to see absolutely every qualification gained during education?

Employers are not really expecting to see GCSE results, unless of course you are applying for teaching positions in schools. I would write the subjects without the grades. The skills/responsibilities gained from his job or any volunteering will be more important to highlight on the CV.