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rashid47010
16th March 2012, 09:57 PM
Dear All,

Can anybody guide me about the files under the boot directory. I found majorly three kind of files under the boot directory:

[root@localhost boot]# ls -l
total 72064
-rw-r--r--. 1 root root 111286 Feb 9 04:29 config-3.2.5-3.fc16.x86_64
-rw-r--r--. 1 root root 111642 Mar 1 04:46 config-3.2.9-1.fc16.x86_64
-rw-r--r--. 1 root root 111631 Mar 6 00:00 config-3.2.9-2.fc16.x86_64
-rw-r--r--. 1 root root 18421 Feb 9 04:30 config.mk-compat-wireless-3.3-rc1-2-3.2.5-3.fc16.x86_64
-rw-r--r--. 1 root root 18421 Mar 1 04:46 config.mk-compat-wireless-3.3-rc1-2-3.2.9-1.fc16.x86_64
-rw-r--r--. 1 root root 18421 Mar 6 00:01 config.mk-compat-wireless-3.3-rc1-2-3.2.9-2.fc16.x86_64
drwxr-xr-x. 2 root root 4096 Mar 16 22:46 grub
drwxr-xr-x. 3 root root 12288 Mar 16 23:37 grub2
-rw-r--r--. 1 root root 17366990 Feb 12 10:49 initramfs-3.2.5-3.fc16.x86_64.img
-rw-r--r--. 1 root root 17369094 Mar 7 15:12 initramfs-3.2.9-1.fc16.x86_64.img
-rw-r--r--. 1 root root 17649556 Mar 16 23:37 initramfs-3.2.9-2.fc16.x86_64.img
drwx------. 2 root root 16384 Nov 23 06:43 lost+found
-rw-------. 1 root root 2375423 Feb 9 04:29 System.map-3.2.5-3.fc16.x86_64
-rw-------. 1 root root 2375977 Mar 1 04:46 System.map-3.2.9-1.fc16.x86_64
-rw-------. 1 root root 2377810 Mar 6 00:00 System.map-3.2.9-2.fc16.x86_64
-rwxr-xr-x. 1 root root 4604656 Feb 9 04:29 vmlinuz-3.2.5-3.fc16.x86_64
-rwxr-xr-x. 1 root root 4607440 Mar 1 04:46 vmlinuz-3.2.9-1.fc16.x86_64
-rwxr-xr-x. 1 root root 4614992 Mar 6 00:00 vmlinuz-3.2.9-2.fc16.x86_64
[root@localhost boot]#

I need to know about the config-* and System.map files

stoat
17th March 2012, 02:34 AM
I need to know about the config-* and System.map filesThe config-* files contain the settings for all of the configuration options that were used for building the kernels. I know that doesn't say much. When a kernel is compiled, there is a file named .config in the kernel source tree which is read by the kernel configuration editor started by the make menuconfig command (or one of the variations of it). The configuration editor displays all of the config options that will be built into the kernel and provides a means for altering them. If any changes are made, then they are saved to that .config file when the configuration editor is closed. Then the make command builds the kernel using those settings. When it's all done, the .config file used to build the kernel usually is copied to the /boot directory, and those three files you are seeing are those copies. I don't know of any purpose that they serve after the kernel is built other than to be examined visually (which I often need to do to remind myself of how some option is set), or to use again by copying it back to .config in the source tree to rebuild the kernel again with those same config settings.

The System.map file contains a table of kernel symbols and their addresses. I have never had any reason to do anything with that file, but the kernel apparently does.

goodfella
24th March 2012, 01:56 AM
Dear All,

Can anybody guide me about the files under the boot directory. I found majorly three kind of files under the boot directory:

[root@localhost boot]# ls -l
total 72064
-rw-r--r--. 1 root root 111286 Feb 9 04:29 config-3.2.5-3.fc16.x86_64
-rw-r--r--. 1 root root 111642 Mar 1 04:46 config-3.2.9-1.fc16.x86_64
-rw-r--r--. 1 root root 111631 Mar 6 00:00 config-3.2.9-2.fc16.x86_64
-rw-r--r--. 1 root root 18421 Feb 9 04:30 config.mk-compat-wireless-3.3-rc1-2-3.2.5-3.fc16.x86_64
-rw-r--r--. 1 root root 18421 Mar 1 04:46 config.mk-compat-wireless-3.3-rc1-2-3.2.9-1.fc16.x86_64
-rw-r--r--. 1 root root 18421 Mar 6 00:01 config.mk-compat-wireless-3.3-rc1-2-3.2.9-2.fc16.x86_64
drwxr-xr-x. 2 root root 4096 Mar 16 22:46 grub
drwxr-xr-x. 3 root root 12288 Mar 16 23:37 grub2
-rw-r--r--. 1 root root 17366990 Feb 12 10:49 initramfs-3.2.5-3.fc16.x86_64.img
-rw-r--r--. 1 root root 17369094 Mar 7 15:12 initramfs-3.2.9-1.fc16.x86_64.img
-rw-r--r--. 1 root root 17649556 Mar 16 23:37 initramfs-3.2.9-2.fc16.x86_64.img
drwx------. 2 root root 16384 Nov 23 06:43 lost+found
-rw-------. 1 root root 2375423 Feb 9 04:29 System.map-3.2.5-3.fc16.x86_64
-rw-------. 1 root root 2375977 Mar 1 04:46 System.map-3.2.9-1.fc16.x86_64
-rw-------. 1 root root 2377810 Mar 6 00:00 System.map-3.2.9-2.fc16.x86_64
-rwxr-xr-x. 1 root root 4604656 Feb 9 04:29 vmlinuz-3.2.5-3.fc16.x86_64
-rwxr-xr-x. 1 root root 4607440 Mar 1 04:46 vmlinuz-3.2.9-1.fc16.x86_64
-rwxr-xr-x. 1 root root 4614992 Mar 6 00:00 vmlinuz-3.2.9-2.fc16.x86_64
[root@localhost boot]#

I need to know about the config-* and System.map files


The config.mk-compat-wireless* files can be used to build older kernels which had less wireless
capabilities and/or bugs. You will not need them otherwise.

The other three config files are associated with each kernel version. The define if a module is built or not,
whether it is part of the kernel, or a module that is loaded.

The pre-built kernels have a ton of drivers built so that Linux runs on all the different hardware out
in the world. You can trim out quite a bit of "the fat" if you build your own kernel. And you won't be tied
to someone's defintion of what a release kernel is. Although, I think the Fedora release kernels work well
given the variety of cpu's, and hardware.

The map files are a map of kernel text, data, bss symbols. Useful if you are debugging the kernel.