On 22/05/15 13:26, Liming Sun wrote:
Hi, I have some basic question about how to integrate some new library or tool, such as NFS. Is there any guidance or example about the steps in general? I did some search but couldn't find any easy steps.
Good question, though it's not possible to give a generic answer. I'll explain and you can refine the question if necessary. If you include more specific knowledge of what you want integrated and where, the answer can be better.
Now, NFS, specifically, is made up a kernel part and a userspace part. The kernel part is the file system driver itself, and the userspace part is mount_nfs(8), which handles the initial RPC dance for getting the file handle used to mount NFS. The kernel part is easy. It's already shipped by everything that uses buildrump.sh. Generally speaking, all kernelside functionality is best integrated by submitting it to the upstream anykernel (currently always NetBSD), and then we get it in rump kernel projects for free without having to do anything except checkout new enough upstream anykernel sources. If the kernel code can't for some reason go into upstream, some other place needs to be figured out. One such example is buildrump.sh/brlib.
The userspace part, i.e. mount_nfs(8), is a bit different from the kernel part, because you need a userspace environment to compile/run it. That's not available except for rumprun and rumpctrl, so if you want to support NFS in some other environment, you more or less have to rely on your own creativity. For rumpctrl mount_nfs can be supported easily. For rumprun it's a bit trickier, since we haven't yet figured out how to include multiple configuration programs in a single unikernel image. That said, we'll get there eventually.
- antti
