There are a lot of classics which can be listed here, but the following two w.r.t. systems software come to mind;

1) Systems Programming by John Donovan. A classic from the 1970s, one of the first to really lay out the software interface to hardware in practical terms.

2) System Software: An Introduction to Systems Programming by Leland Beck. This is sort of a successor to the above but from the 1980s/1990s.

There are too few books on this subject and with the rise of Hypervisors/VMs, Managed Languages, Containers, Emulators etc. we need a practical survey book on this entire domain.

I love these. Thanks!