See 2107 Release Notes, 2106 Release Notes. Both releases had a LOT of bug fixes and code cleanups, focusing on compatibility and code quality. The AOT pipeline also got multithreading support.

FEX-2107

Compatibility & Bug Fixes

• Fixes bugs in unaligned atomic signal handlers
• CPUID cleanups
• Fixed a memory leak in Register Allocation
• Several syscall fixes (pidfd_send_signal, arch_prctl, fcntl, send(m)msg, shmdt, recvmsg, *chown32, edge cases around time syscalls, 32/tmpfile)
• Implement more syscalls (setfsuid32, setfsgid32, getgroups32, setgroups32, settimeofday, futimesat, utimes, 32/sigpending, 32/truncate64)
• Deferred signal handler registration, fixes bash (pts handover)
• Fixed handling of some rare elf files
• Implemented 32 bit iret

Usability

• Adds support for squashfs based rootfses
• cpack support for debian packaging

Performance

• Huge page support in our VA allocator

Misc

• Reduce warnings
• Several assorted Cleanups
• Relocate ELF handling logic to the os frontend
• Improve logging SNR

The detailed change log is available on Github

FEX-2106

Compatibility & Bug Fixes

• Several syscall bug fixes (pselect, epool, semctl, msgctl, pidfd_getfd, poll, fadvise64, sigaction, mmap, epoll, uname, openat, …)
• Implemented SSE4.1

Performance

• Multi threaded AOTGen
• Optimized ioctl/drm marshaling

Misc

• Several minor cleanups & refactors

The detailed change log is available on Github