/boot
This directory contains everything required for the boot process except for configuration files not needed at boot time and the map installer. Thus, the /boot directory stores data that is used before the kernel begins executing user-mode programs. This may include redundant (back-up) master boot records, sector/system map files, the kernel and other important boot files and data that is not directly edited by hand. Programs necessary to arrange for the boot loader to be able to boot a file are placed in /sbin. Configuration files for boot loader are placed in /etc. The system kernel is located in either / or /boot (or as under Debian in /boot but is actually a symbolically link at / in accordance with the FSSTND)
/boot/config-kernel-version
Installed kernel configuration. This file is most useful when compiling kernels on other systems or device modules. Below is a small sample of what the contents of the file looks like.
CONFIG_X86=y
CONFIG_MICROCODE=m
CONFIG_X86_MSR=m
CONFIG_MATH_EMULATION=y
CONFIG_MTRR=y
CONFIG_MODULES=y
CONFIG_MODVERSIONS=y
CONFIG_SCSI_DEBUG=m
CONFIG_I2O=m
CONFIG_ARCNET_ETH=y
CONFIG_FMV18X=m
CONFIG_HPLAN_PLUS=m
CONFIG_ETH16I=m
CONFIG_NE2000=m
CONFIG_HISAX_HFC_PCI=y
CONFIG_ISDN_DRV_AVMB1_C4=m
CONFIG_USB_RIO500=m
CONFIG_QUOTA=y
CONFIG_AUTOFS_FS=m
CONFIG_ADFS_FS=m
CONFIG_AFFS_FS=m
CONFIG_HFS_FS=m
CONFIG_FAT_FS=y
CONFIG_MSDOS_FS=y
CONFIG_UMSDOS_FS=m
CONFIG_FBCON_VGA=m
CONFIG_FONT_8x8=y
CONFIG_FONT_8x16=y
CONFIG_SOUND=m
CONFIG_SOUND_CMPCI=m
CONFIG_AEDSP16=mThe line begins with the configuration option and whether it's configured as part of the kernel, as a module or not at all. Lines beginning with a # symbol are comments and are not interpreted during processing.
/boot/vmlinuz-kernel-version
Normally the kernel or symbolic link to the kernel.
/boot/grub
This subdirectory contains the GRUB configuration files including boot-up images and sounds. GRUB is the GNU Grand Unified Bootloader, a project which intended to solve all bootup problems once and for all. One of the most interesting features, is that you don't have to install a new partition or kernel, you can change all parameters at boot time via the GRUB Console, since it knows the filesystems.
/boot/grub/device.map
Maps devices in /dev to those used by grub.
/boot/grub/grub.conf, /boot/grub/menu.lst
Grub configuration file.
/boot/grub/messages
Grub boot-up welcome message.