2017-08-31 4:47 GMT-03:00 Andrew Savchenko <birc...@gentoo.org>: > Hi, > > On Thu, 24 Aug 2017 18:27:22 -0300 Francisco Ares wrote: > > Hi, All. > > > > This is a rather special case, so I don't expect much, but who knows? > > > > I've built a Gentoo x86-64 system for an embedded application. > > > > Just after a lot of updates, which I am unable to track, it stopped > working > > as usual. > > > > There is the development system, fully loaded of a lot of packages used > for > > development, and the production system, that don't need all of those. > > > > There is a line in both systems in /etc/iniitab responsible for > auto-login > > the production system user and the programs we need running (in its > > ".bash_profile" and ".xinitrc"): > > > > c6:2345:respawn:/sbin/agetty -a production-user 38400 tty6 linux > > > > The development system starts a WindowMaker session, and the production > > system starts a program that controls the rest of the hardware of this > > embedded system, with an X11 graphical interface. That runs normally > when > > simulated at the development system. > > > > The development system runs smoothly. The production system, after > > removing the files from undesirable packages and creating a squashfs > image > > of the ripped-off root partition behaves strangely at boot: > > > > It shows the initialization messages as expected, but when the auto-login > > and the controller program start should take place, it completely stalls > up > > to I plug a USB keyboard and issue some times some of the key > combinations > > to change to a text console and back to X11 (Ctrl-Alt-F1 and > Ctrl-Alt-F6); > > only then the things resume as expected. > > > > As you might suspect, there is no keyboard for the production system ;-) > . > > > > As a matter of fact, I don't know where the stall take place, as when I > try > > to switch to a text console to see the logs, it switches back to X11 and > > starts our program. By the way, the logs just show that the events > > occurred at latter times than expected. > > > > Although the squashfs is read-only, some main directories are arranged > in a > > way that, using tmpfs mounts and unionfs with the read-only directory to > > the read-write tmpfs directory to that main directory provide a way of > > creating temporary files that has been working for a few years now. > > > > For instance, in "/etc/fstab": > > > > tmpfs /.etc.rw tmpfs defaults,mode=755 > > 0 0 > > union /etc unionfs > > default_permissions,allow_other,use_ino,nonempty,suid, > cow,dirs=/. > > etc.rw=rw:/.etc.ro=ro 0 0 > > > > And there is a "/.etc.ro" with a copy of all files present in regular > > "/etc" , a "/.etc.rw" directory to be mounted tmpfs, and the original > > "/etc" directory, that needs to be there at boot, even before mounting > all > > this. > > > > Does anyone have a clue? > > Try to dissect your problem. Start with removing squashfs and all > tmpfs/unionfs manipulations. Create the same image, but on "normal" > writable file system and see how it goes. It may be fs-related bug, > may be you removed too many files and some "undesired" packages are > actually mandatory. > > If you have some form on snapshots of your changes, you can try to > bisect them in a git bisect way. > > Another approach is to run X server (or any other app suspected as > a troublemaker) under strace (or attach strace to a running process) > and see what is going on. You will have a lot of low level > information and extensive filtering will be required; strace is > capable of that, but you will need to dig into its documentation. > > Best regards, > Andrew Savchenko >
Hi All, After days and days struggling, I finally upgraded to the newest stable kernel and updated every package with a "emerge -e", just in case, twice! Then, rebuilt the kernel again. So, like a charm, everything got back to work as before. Unfortunately, will never know what piece of code that issue was. Thank you, and Best Regards, Francisco
