[Buildroot] device_table & /dev/shm

Charles Krinke charles.krinke at gmail.com
Sat Jun 25 18:29:46 UTC 2011


I have two issues I dont understand and am hoping for a few clues to
help me navigate through the "Swamp of Confusion" to the "Ridge of
Enlightment".

1. I can see the generic device_table.txt and it includes a /dev/shm
node. I can also see the /dev structure in output/target and it
matches the generic device_table.txt. But, ... when I build the jffs2
and load it on my MPC8323 target, what I see in /dev does not include
/dev/shm. In fact it is significantly different. So, my first question
is:

"What besides generic/device_table.txt can determine the contents of
/dev on an MPC8323 target?"

2. I can see that named semaphores are not working. That is,
sem_open() called from an application program fails with ENOSYS. In
researching this, I can see that this depends on part on /dev/shm and
linking with -lrt. It also appears that the default /etc/fstab does
not use /dev/shm. My second question is:

"What are the items that can go awry in an MPC8323 system that may
cause named semaphores using the sem_open() call to fail?"

-- 
Charles Krinke


More information about the buildroot mailing list