A report to UK Parliament has some really good news - that some schools have managed to close the gap in outcomes for boys & girls & they've done it without extra resources or extra money. One of the authors summarised it this way:

A central finding was that the teachers (and other adults) were not treating the boys fairly. They were more strict with discipline, but softer on rewards for boys: giving praise for lower quality work than for their girls. It is well known that the majority of students who struggle with literacy are boys and so, when these two unfairnesses were corrected (plus a bunch of other actions to support) the boys’ achievement rose to that of the girls without any special tutoring etc.

This means that boys’ underachievement in a school is the result of unconscious choices the school is making, not something intrinsic to boys.

In summary, boys outcomes will improve if you just take your foot off their throat.