Volatile Keyword C:
Volatile almost useless for multi-threaded-programming (*)Solaris 9 not booting?
/etc/system does not exist?
Driver crashing while booting?
System not booting in single user mode? .............. If answer is YES, go ahead and read
An interactive boot (boot -a) stops and asks for input during the boot process. The system provides a dialog box in which it displays the default boot values and gives you the option of changing them. You might want to boot interactively to make a temporary change to the system file or kernel. Booting interactively enables you to test your changes and recover easily if you have problems. To do this, follow the process in Step by Step 3.1.
At the ok prompt, type boot -a and press Enter. The boot program prompts you interactively.
Press Enter to use the default kernel (/kernel/unix) as prompted, or type the name of the kernel to use for booting and then press Enter.
Press Enter to use the default modules directory path as prompted, or type the path for the modules directory and then press Enter.
Press Enter to use the default /etc/system file as prompted, or type the name of the system file and then press Enter.
Press Enter to use the default root file system type as prompted (that is, ufs for local disk booting or nfs for diskless clients).
Press Enter to use the default physical name of the root device as prompted or type the device name.
TIP
The Interactive Boot Process For the exam, you should make sure you understand what each step of an interactive boot process is asking for. For example, you should know the name of the default kernel, know what the default modules are and where they are located, understand what the /etc/system file is used for, and what is meant by the default root file system. Each of these are described in the section "The Kernel," later in this chapter.
The following output shows an example of an interactive boot session:
ok
ok boot -a
Boot device: /pci@1f,0/pci@1,1/ide@3/disk@0,0:a File and args: -a
Enter filename [kernel/sparcv9/unix]:
Enter default directory for modules [/platform/SUNW,Ultra-5_10/kernel
/platform/sun4u/kernel /kernel /usr/kernel]:
Name of system file [etc/system]:
SunOS Release 5.9 Version Generic_112233-02 64-bit
Copyright 1983-2002 Sun Microsystems, Inc. All rights reserved.
root filesystem type [ufs]:
Enter physical name of root device
[/pci@1f,0/pci@1,1/ide@3/disk@0,0:a]:
configuring IPv4 interfaces: hme0.
configuring IPv6 interfaces: hme0.
Hostname: ultra5
The system is coming up. Please wait.
checking ufs filesystems
/dev/rdsk/c0t0d0s5: is clean.
/dev/rdsk/c0t0d0s7: is clean.
/dev/rdsk/c0t0d0s6: is clean.
Starting IPv6 neighbor discovery.
Setting default IPv6 interface for multicast: add net ff00::/8: \
gateway ultra5
Starting rpc services: rpcbind done.
Setting default IPv4 interface for multicast: add net 224.0/4:
Print services started.
volume management starting.
Mar 13 09:21:48
The system is ready.
ultra5 console login: NOTE
A Missing /etc/system File If the /etc/system file is missing at bootup, you see this message:
Warning cannot open system file!
The system still boots, however, using all "default" kernel parameters. Because by default the lines in the /etc/system file are all commented by the asterisk (*) character, /etc/system is actually an "empty" file. The kernel doesn't use anything from this file until you edit this file and enter an uncommented line. You can specify /dev/null (an empty file) for the system filename, and the system still boots. In fact, if the /etc/system file gets corrupted and the system won't boot from the /etc/system/dev/null to get the system to boot. file, you can specify a file named
{1} ok boot
FATAL: system is not bootable, boot command is disabled
Which is about as helpful as someone telling me the box is currently a brick. Which I know already. Anyway just in case you happen to hit this the fix/workaround is to set auto-boot? to false, reset the box, and then set it to true and finally boot as shown below. {1} ok setenv auto-boot? false
auto-boot? = false
{1} ok reset-all
SC Alert: Host System has Reset
Sun Fire V210, No Keyboard
Copyright 1998-2003 Sun Microsystems, Inc. All rights reserved.
OpenBoot 4.11.4, 4096 MB memory installed, Serial #xxxxxxxx.
Ethernet address 0:3:ba:xx:xx:xx, Host ID: 83xxxxxx.
{1} ok setenv auto-boot? true
auto-boot? = true
{1} ok boot
.......... lots of output ........
volume management starting.
The system is ready.
xxxxxx console login:
Jeremy Bettis
Mon, 11 Sep 2006 07:20:35 -0700
1) Strip can remove debug symbols, and write them to a separate file:3) gdb is ok with add-symbol-file on dynamic libraries before they have been loaded. If gdb would automatically look for the symbol files by some algorithm, that would be wonderful. The appeal of being able to ship a stripped version of my software and then being able to drop in the symbol files and start debugging, is almost too good to resist.
strip shared_debug_obj/app.exe -o app.exe
strip shared_debug_obj/app.exe --only-keep-debug -o app.dbg
strip shared_debug_obj/lib.dll -o lib.dll
strip shared_debug_obj/lib.dll --only-keep-debug -o lib.dbg
2) gdb can read the separate symbol files, but only if you tell it too:
add-symbol-file app.dbg
add-symbol-file lib.dbg