“The kernel interface is complex. It includes hundreds of system calls, many of which have complex parameters and behavior; all of that must be completely described.”
The Linux kernel has promised for decades not to break userspace. But it has never had a formal specification of what the ABI actually is. Sasha Levin’s framework tries to fix that with macro-based declarations that describe system calls, sysfs attributes, and ioctls. Each spec adds about 4KB, so a fully specified kernel would carry several megabytes of extra data. The real challenge isn’t technical. It’s convincing kernel developers that maintaining thousands of lines of specification is worth the effort.