On Thu, Oct 25, 2012 at 11:46 AM, Robert P. J. Day <rpjday@xxxxxxxxxxxxxx> wrote: > > looking at the "uapi" reorganization in the kernel source for the > first time, and a couple things confuse me. > > i see the principle -- collect all the userspace API content in one > place, in this case include/uapi/. this obviously(?) is supposed to > represent a newer way to represent what you got formerly with > > $ make headers_install > > that is, header files identified in Kbuild files, cleansed of any > kernel-only content, then placed under usr/include in the source tree. > is that about right -- is that what it's supposed to represent? Read this guy as well: http://lwn.net/Articles/507794/ So avoiding issues with double dependency is really another objective. > so at a *guess*, it would seem that, if a header file that should be > part of uapi didn't need any cleaning, it could go straight into > include/uapi untouched. Yup. > on the other hand, if a header file *did* have some kernel-only > content, i would have *thought* that there would be two versions of > that header file: > > a) the one with the kernel-only content still under include/linux, > which would turn around and, in some way, include .. It includes the respective uapi header as well. > b) the common content file under include/uapi > > does that make sense? because i took a quick look and here's an > example i don't understand. there's include/linux/coda.h, with the > contents: > > #if defined(__linux__) > typedef unsigned long long u_quad_t; > #else > #endif > #include <uapi/linux/coda.h> > #endif > > ok, so far, so good. but then there's this in > include/uapi/linux/coda.h: > > ... snip ... > #ifdef KERNEL <--- ????? > typedef unsigned long u_long; > typedef unsigned int u_int; > typedef unsigned short u_short; > typedef u_long ino_t; > typedef u_long dev_t; > typedef void * caddr_t; > ... snip ... Interesting, not sure. David ? I do see some BSD'ish deps there (#if defined(__NetBSD__))... so not sure if that was left to them or what. > why is there still kernel-only content in the uapi/ directory? > maybe i just don't understand the rationale for what's going on here. No, I'm as puzzled. Luis _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
