On Fri, Mar 01, 2019 at 04:03:09PM +0900, Masami Hiramatsu wrote: > Hi Joel, > > On Thu, 28 Feb 2019 22:26:11 -0500 > Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote: > > > On Fri, Mar 01, 2019 at 11:28:26AM +0900, Masami Hiramatsu wrote: [..] > > There are many usecases for this, I have often run into issues with Linux > > over the years not only with Android, but other distros, where I boot custom > > kernels with no linux-headers package. This is quite painful. It is > > convenient to have it as /proc file since the file is dependent on kernel > > being booted up and this will work across all Linux distros and systems. I > > feel that if you can keep an open mind about it, you will see that a lot of > > people will use this feature if it is accepted and there is a lot of positive > > feedback in earlier posts of this set. > > I don't complain about having headers for custom boot kernel. I agree with you > that having kernel headers for debugging is always good. :) > So google recommends built-in, it is reasonable. Ok, thanks :) > > > > > > The code to read the headers is based on /proc/config.gz code and uses > > > > > > the same technique to embed the headers. > > > > > > > > > > > > To build a module, the below steps have been tested on an x86 machine: > > > > > > modprobe kheaders > > > > > > rm -rf $HOME/headers > > > > > > mkdir -p $HOME/headers > > > > > > tar -xvf /proc/kheaders.tar.xz -C $HOME/headers >/dev/null > > > > > > cd my-kernel-module > > > > > > make -C $HOME/headers M=$(pwd) modules > > > > > > rmmod kheaders > > > > > > > > > > It seems a bit complex, but no difference from compared with carrying > > > > > kheaders.tar.gz. I think we would better have a psudo filesystem > > > > > which can mount this compressed header file directly :) Then it becomes > > > > > simpler, like > > > > > > > > > > modprobe headerfs > > > > > mkdir $HOME/headers > > > > > mount -t headerfs $HOME/headers > > > > > > > > > > And this doesn't consume any disk-space. > > > > > > > > I felt using a compressed tar is really the easiest way because of all the > > > > tools are already available. > > > > > > As I asked above, if the pure tarball is useful, you can simply ask vendors > > > to put the header tarball on their vendor directory. I feel making it as > > > a module is not a right way. > > > > I don't see what is the drawback of making it a module, it makes it well > > integrated into kernel build and ecosystem. I also didn't see any > > justification you're providing about why it cannot be a module. If you go > > through this and earlier threads, a lot of people are Ok with having a module > > option. And I asked several top kernel maintainers at LPC and many people > > suggested having it as a module. > > I meant, if we have a tarball, we don't need any operation of loading/unloading > kmodules. But if we have this as built-in, yes, this would be much easier to > deploy it to device. > > Anyway, having that option (make it as a module) is not bad. IMHO, that may > be more complicated than just have a tarball file, but it is a user's choice. > > OK, now I understand it. Sounds good. :) Just sent out v4. thanks, - Joel
