On Sat, 2020-05-02 at 19:02 +0200, Thomas Trepl via lfs-dev wrote: > Am Freitag, den 01.05.2020, 15:53 +0200 schrieb Pierre Labastie via > lfs-dev: > > Hi, > > > > I propose a new way to build LFS, which removes the need for the > > /tools > > symlink, and decreases the number of tweaks needed when building > > gcc. > > > > The current build builds a cross-compiler in pass1, and uses it as > > a > > native compiler in pass2. This needs to use a non standard > > directory > > (/tools) to host the toolchain and insulate it from the build > > machine. > > > > The modified build uses the cross compiler to cross compile > > packages > > that need themselves to be rebuilt, thus insulating them > > automatically > > from the host, without the need for a non standard directory > > layout. > > Chroot is entered as soon as possible, and the remaining chapter 5 > > packages are built in chroot. > > Wow, quite interesting! I'd vote to have a deeper look to that > mechanism. > > > This is WIP: the text must be improved at several places, bison and > > flex may be moved to after chroot (to be tested). But the commands > > seem > > to produce an acceptable system, with almost clean ICA. > > > > You can view it at [1], only for sys V since I have not tested > > systemd > > yet (I do not expect many changes). > > > > There are pros and cons compared to the current method: > > > > pros: no /tools symlink, no need to tweak gcc sources, no need to > > build twice ld in binutils-pass2, no need to readjust the toolchain > > after chapter 6 glibc, no need to tweak the gcc specs, no need to > > reinstall kernel headers in chapter 6. > > The less we have to tweak core packages (and gcc is for sure one of > them), the better. I would see that as a great benefit. > > > cons: chroot is entered in the middle of chapter 5 (maybe chapter > > 5 > > should be split), the debug sections of several packages reference > > x86_64-lfs-linux-gnu instead of x86_64-pc-linux-gnu, binutils-pass2 > > needs "enable-shared". > Ok, here is the "traditional" separation of Chapter 5 (as run with > host tools) and the Chapter 6 (running previously built tools in > chroot) in danger. But at the end, its just a naming issue. > > With your method we have kinda Chapter 5a building core tools, a > Chapter 5b building toolchain for full build using 5a in chroot and > finally the well-known Chapter 6. > > For the cost of entering the chroot in the middle of chap5, we got > rid > of the adjusting which sometimes causes trouble for newbies. This > knot > is simply untied. > > > Another pro, not tried, is that some simple packages built in > > chapter 5 > > may be built only once if testing them is not required. > > > > Comments and suggestions for improvement (there's a lot of room for > > improvement) welcome. > > Its great! I'd see that as a big evolution step in the LFS > ecosystem. > > I see a restart to continue not more complicated as it is now. When > continuing an interrupted build in chap5 now, user has also to > prepare > the environment carefully. Same in new chapter 5a so no change here. > Continuing in chap 5b, only need to reenter the chroot, this not any > different to want currently has to be done while it comes a few steps > earlier. > > Maybe the new Chapter 5 should end with leaving the chroot > environment > with unmounting the virtFS. It could be a proper end to chap5 as at > this stage, a backup of the system might be recommended (as a hint > for > the user). > The new chapter 6 should then reenter the chroot env again. IMHO this > would make the differentiation of chap5 and 6 a bit easier. >
Thanks to all who answered. The book source is now available at: svn co svn://svn.linuxfromscratch.org/LFS/branches/cross-chap5 Some fixes have been done, but there is still a problem with ncurses: the terminfo database is not built because it needs tic from the build host, and we do not require it. Then using the terminal in chroot is painful (no backspace nor line editing capability). One simple fix would be to require tic on the build host with version greater than or equal to 6.0, and remove the --disable-db-install switch. Another fix would be to first build ncurses for the build host (no cross-compile), and use the just built tic (there are configure switches for that). Another fix is to cheat and use the cross-compiled tic on the build host (but it's not pure cross compilation anymore). Pierre -- http://lists.linuxfromscratch.org/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
