Gentoo Archives: gentoo-user

From: Francisco Ares <frares@×××××.com>
To: gentoo-user <gentoo-user@l.g.o>
Subject: [gentoo-user] strange behaviour in quite special case
Date: Thu, 24 Aug 2017 21:28:10
1 Hi, All.
3 This is a rather special case, so I don't expect much, but who knows?
5 I've built a Gentoo x86-64 system for an embedded application.
7 Just after a lot of updates, which I am unable to track, it stopped working
8 as usual.
10 There is the development system, fully loaded of a lot of packages used for
11 development, and the production system, that don't need all of those.
13 There is a line in both systems in /etc/iniitab responsible for auto-login
14 the production system user and the programs we need running (in its
15 ".bash_profile" and ".xinitrc"):
17 c6:2345:respawn:/sbin/agetty -a production-user 38400 tty6 linux
19 The development system starts a WindowMaker session, and the production
20 system starts a program that controls the rest of the hardware of this
21 embedded system, with an X11 graphical interface. That runs normally when
22 simulated at the development system.
24 The development system runs smoothly. The production system, after
25 removing the files from undesirable packages and creating a squashfs image
26 of the ripped-off root partition behaves strangely at boot:
28 It shows the initialization messages as expected, but when the auto-login
29 and the controller program start should take place, it completely stalls up
30 to I plug a USB keyboard and issue some times some of the key combinations
31 to change to a text console and back to X11 (Ctrl-Alt-F1 and Ctrl-Alt-F6);
32 only then the things resume as expected.
34 As you might suspect, there is no keyboard for the production system ;-) .
36 As a matter of fact, I don't know where the stall take place, as when I try
37 to switch to a text console to see the logs, it switches back to X11 and
38 starts our program. By the way, the logs just show that the events
39 occurred at latter times than expected.
41 Although the squashfs is read-only, some main directories are arranged in a
42 way that, using tmpfs mounts and unionfs with the read-only directory to
43 the read-write tmpfs directory to that main directory provide a way of
44 creating temporary files that has been working for a few years now.
46 For instance, in "/etc/fstab":
48 tmpfs / tmpfs defaults,mode=755
49 0 0
50 union /etc unionfs
51 default_permissions,allow_other,use_ino,nonempty,suid,cow,dirs=/.
52 0 0
54 And there is a "/" with a copy of all files present in regular
55 "/etc" , a "/" directory to be mounted tmpfs, and the original
56 "/etc" directory, that needs to be there at boot, even before mounting all
57 this.
59 Does anyone have a clue?
61 Thanks!
62 Francisco


Subject Author
Re: [gentoo-user] strange behaviour in quite special case Andrew Savchenko <bircoph@g.o>