ECE497 Listings for Embedded Linux Primer Chapter 6

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Number Page Caption Listing
6-1 6-4 Contents of Minimal File System
/
|-- bin
|   |-- busybox
|   '-- sh -> busybox
|-- dev
|   '-- console
|-- etc
|   '-- init.d
|       '-- rcS
'-- lib
    |-- ld-2.3.2.so
    |-- ld-linux.so.2 -> ld-2.3.2.so
    |-- libc-2.3.2.so
    '-- libc.so.6 -> libc-2.3.2.so
 
5 directories, 8 files
6-2 6-7 Final Boot Steps from main.c
...
	if (execute_command) {
		run_init_process(execute_command);
		printk(KERN_WARNING "Failed to execute %s.  Attempting "
					"defaults...\n", execute_command);
	}
	run_init_process("/sbin/init");
	run_init_process("/etc/init");
	run_init_process("/bin/init");
	run_init_process("/bin/sh");

	panic("No init found.  Try passing init= option to kernel.");
}
6-3 6-11 Final Boot Steps from main.c

6-4 6-12 Runlevel Directory Structure on Beagle
$ ls -dl /etc/rc* 
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc0.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc1.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc2.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc3.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc4.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc5.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rc6.d
drwxr-xr-x 2 root root 4096 Mar 13 20:18 /etc/rcS.d
6-5 6-12 Example Runlevel Directory on Beagle
$ ls -ls rc5.d/
total 0
0 lrwxrwxrwx 1 root root 20 Mar 13 20:18 S05led-config -> ../init.d/led-config
0 lrwxrwxrwx 1 root root 18 Mar 13 20:18 S10dropbear -> ../init.d/dropbear
0 lrwxrwxrwx 1 root root 14 Mar 13 20:18 S20apmd -> ../init.d/apmd
0 lrwxrwxrwx 1 root root 16 Mar 13 20:18 S20dbus-1 -> ../init.d/dbus-1
0 lrwxrwxrwx 1 root root 16 Mar 13 20:18 S20syslog -> ../init.d/syslog
0 lrwxrwxrwx 1 root root 22 Mar 13 20:18 S21avahi-daemon -> ../init.d/avahi-daen
0 lrwxrwxrwx 1 root root 17 Mar 13 20:18 S22connman -> ../init.d/connman
0 lrwxrwxrwx 1 root root 17 Mar 13 20:18 S30ntpdate -> ../init.d/ntpdate
0 lrwxrwxrwx 1 root root 20 Mar 13 20:18 S50usb-gadget -> ../init.d/usb-gadget
0 lrwxrwxrwx 1 root root 16 Mar 13 20:18 S99gpe-dm -> ../init.d/gpe-dm
0 lrwxrwxrwx 1 root root 19 Mar 13 20:18 S99rmnologin -> ../init.d/rmnologin
0 lrwxrwxrwx 1 root root 20 Mar  4 22:09 S99zzapsplash -> ../init.d/zzapsplash
6-6 6- Example Runlevel Directory on Beagle

6-13 6-23 Kernel initramfs Build Directory
total 60
-rw-r--r-- 1 yoder yoder  1620 Mar  8 11:19 Kconfig
-rw-r--r-- 1 yoder yoder  1876 Mar  8 11:19 Makefile
-rw-r--r-- 1 yoder yoder   741 Mar  9 12:43 built-in.o
-rwxr-xr-x 1 yoder yoder 18280 Mar  8 13:03 gen_init_cpio
-rw-r--r-- 1 yoder yoder 12536 Mar  8 11:19 gen_init_cpio.c
-rw-r--r-- 1 yoder yoder  1024 Mar  8 11:19 initramfs_data.S
-rw-r--r-- 1 yoder yoder   133 Mar  8 13:03 initramfs_data.cpio.gz
-rw-r--r-- 1 yoder yoder   741 Mar  8 13:03 initramfs_data.o
-rw-r--r-- 1 yoder yoder     0 Mar  8 13:18 modules.order
6-14 6-25 Kernel initramfs Build Directory
dir /dev 0755 0 0
nod /dev/console 0600 0 0 c 5 1
dir /root 0700 0 0
6-15 6-25 Minimal initramfs contents
$ tree .../usr/myinitramfs_root/
. 
|-- bin 
|   |-- busybox 
|   `-- sh -> busybox 
|-- dev 
|   `-- console 
|-- etc 
|   `-- init.d 
|       `-- rcS 
`-- init -> /bin/sh 

4 directories, 5 files