Rethinking the Lib OS from ... Summary

1. Summary

① This paper revisits an old approach to OS construction, the library OS, in a new context.

② The idea of the library OS is that the personality of the OS on which an application depends runs in the address space of the applications

③ The name of idea is Drawbridge which provides a Windows 7 library OS that can run a large set of rich desktop and server applications.

④ With the exception of changes to licensing code, Windows 7 applications run in Drawbridge using unmodified binaries.

⑤ And, the binaries always ran within a sandbox with a read-only copy of the library OS.

 

2. Related work Summary

➀ At a high-level, the Drawbridge design is similar to the original Exokernel design.

➁ which had a kernel responsible for controlling access to the low-level hardware, and the rest of the functionality in the application library.

➂ Whereas Drawbridge provides higher-level APIs of threads and virtual memory, similar to the Cache or Nemesis kernels.

➃ Relative to previous library OS designs, Drawbridge is to show that a large commercial OS can in fact be refactored into a library OS.

➄ Drawbridge incorporates an ABI design that streamlines the library OS implementation without compromising security isolation.

➅ Drawbridge ABI presents higher-level abstractions that trivially share host OS resources, such as CPU and buffer caches.

 

3. The Good

➀ Drawbridge showed how to refactor a large existing monolithic OS to create a self contained library OS.

 

4. The Bad

➀ In Drawbridge, Application checkpoint and restore functionality were implemented.

But, There is no basic reason for this functionality to be part of either the host or the guest.

 

5. Your Comment

Questions to the authors :

I think that It do not compatible with legacy OSes & Apps. Is it right?