Compiling the Linux Kernel

SOURCE: http://www.techenclave.com/printthread.php?t=5099
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Compiling the Linux Kernel [Version 2]

Reasons to recompile your Linux kernel
1.You’ve bought some new hardware and want support for it in Linux.
2.You want to access features of Linux that have been turned off.
3.Something is fishy in your operating system.
4.You want to show off to all your friends and brag about how you are a (false) Linux guru.
5.You have nothing better to do.
6.You really want to.

Compiling the Linux kernel isn’t all that difficult really, but it is admittedly time consuming.
I will divide this tutorial into three parts:
1. Pre-configuration
2. Configuration
3. Post-Configuration

I have used kernel version 2.6.12. This tutorial is specific to 2.6.12 though other kernels in 2.6.x are probably similar. Download the latest version of the Linux kernel from www.kernel.org

I have tried this on two Linux distros :
1. A 32 bit PCQ Linux 2004 (Fedora core based)
2. FC3 – 64 bit. Sadly I was unsuccessful here as I will later explain.

Target Audience:
I have also assumed that the computer in question is a (possibly) dual boot home PC. This document is not really suitable for advanced users. Laptop users should also avoid messing around with their kernel too much – previous versions (2.4.x) have been known to irreparably damage laptops when not configured properly.

The configuration process depends a lot on the hardware you are using.
My setup is:
AMD 64 3200+
512 MB DDR 400 RAM
Nvidia nforce3 150 based motherboard.
Onboard sound Realtek ALC 658 (which, unfortunately is not easily configured in Linux)
ATI Radeon 9600 pro.
Silicon Image 3512A (SATALink)


(Some of you may have seen my previous guide over here. This one, I hope, is more accurate and comprehensive.)

Pre-Configuration

1. Visit www.kernel.org and download the latest stable kernel (at the time of writing it was 2.6.12).
2. Copy the downloaded kernel to /home/USERNAME
3. Uncompress the kernel
4. bunzip2 linux-2.6.12.tar.bz2 if you have the bzipped format
5. gunzip linux-2.6.12.tar.gz if you have downloaded the gzipped format
6. tar –xvf linux-2.6.12.tar
7. Change to the linux directory: cd linux-2.6.12
8. Make mrproper to remove any old configuration files or object files.
i. make mrproper
9. If you want to use an older configuration file then copy it over to .config. If you want a reference configuration file then you can use the config file in the appropriate subdirectory of ~/linux-2.6.12/arch. Actually, if you do nothing, the reference config file is read from the appropriate arch directory.
10. Issue one of four commands
make oldconfig (asks you to add new options as yes/no/module –not recommended)
make menuconfig (uses a terminal not unlike your bios screen)
make xconfig (uses GUI)
make config (first edit .config then run this command – very advanced users only)
Personally I go with make menuconfig. It simple in its design and easy to understand considering that there are well over a thousand options distributed under various subheadings.
If you run a system with KDE running, use make xconfig (issue it from xterm or any other terminal emulator, not the console). It looks quite attractive.
You may run in to problems with this in some cases, try make gconfig for GNOME based GUIs.

Post Configuration
In interests of not scaring the hell out of you, I will tell you the post-configuration section first. Firstly, check the dependencies (whether you have all the tools you need). Information on that can be found in ./Documents/changes.txt file. If you have a distro running any 2.6.x kernel it should be fine.

1. After running one of the make *config methods and saving the .config file you have to make the kernel (actual compilation process).
2. The command is: make.
3. Beware - the above command can take a little while. On my computer it took 6 or 7 minutes (on the 64 bit distro) and 18 minutes on the 32 bit PCQ Linux (there is some sort of bug in that, INIT keeps on restarting itself). It may take longer on slower computers. Don’t worry if it throws up warning messages. These are to do with the Linux source code and there is nothing you can do about them (unless, say, you are a Linux kernel developer).
4. change to root: su
5. Copy the image to /boot directory: cp /home/USERNAME/linux-2.6.12/arch/i386/boot/bzImage /boot/vmlinuz-2.6.12
6. If you are compiling on some architecture other than i386 (e.g. x86_64), replace the i386 above with the appropriate architecture.
7. Install the modules by issuing the command: make modules_install .
8. Copy the system map to /boot directory by issuing the command: cp /home/USERNAME/linux-2.6.12/System.map /boot/System.map-2.6.12
(NOTE: needed only for 3rd party boot managers)
9. Change to the /boot/grub directory : cd /boot/grub
10. Edit grub.conf and include the following lines:
title KingKrool’s Linux kernel 2.6.12
root (hdx, y)
kernel /boot/vmlinuz-2.6.12 ro root=/dev/hdpn
The first line is the title to appear in the Grub screen.

The second line gives the drive on which grub is installed. x and y must be replaced with the appropriate values. Eg. For the second logical drive on the first physical drive x = 0, y = 1. This is not fixed though. The best way would be to boot into Linux (using the old kernel) and use the hardware browser (in System tools of RH /FC distros). Depending on your installation there will be two or three linux partitions. If there are three the smallest will be the boot partition, the largest partition is root and third is swap. If there are two then the larger one is boot+root and second is swap.
If the label given is /dev/hdb3 then x = 1, y = 2.

The third line gives the kernel location. If you have a dedicated boot partition then /boot is not necessary in the path, otherwise the full path is required (i.e. all paths are relative to /boot). In root=dev/hdpn p and n are from above.
If the drive was listed as /dev/hda8 then p = a n = 8 (copy as is).

The simplest way to configure the kernel is to copy the existing code for any Linux kernel and just make a few modifications to the kernel image path.

If you have compiled support for the filesystem of the root partition as a module then you will have to add the following line at the end (4th line)
initrd (/boot)/initrd-2.6.12.img
(/boot) is used only if boot and root partitions are the same.
The file intrd-2.6.12.img has to be made by issuing the command
/sbin/mkinitrd /boot/intird-2.6.12.img `kernel version` where `kernel version` is 2.6.12 to which you append the string (if any) entered in local version.
Even if you have not compiled the FS as a module, it is still recommended to create an initrd – it is needed on several distributions, and will be necessary in the future due to the deprecation of devfs in the kernel (just take my word for it).
Save the file and exit. Reboot your computer and you are ready to use the new kernel!

Remember to leave the old kernel entries intact, that way if you have problems, you can always go back to the old kernel.



CONFIGURATION
NOTES:
Kernel modules are small pieces of compiled code which can be inserted in the running kernel, rather than being permanently built into the kernel. You use the "modprobe" tool to add (and sometimes remove) them.

Only some options can be compiled as modules. In menuconfig, they are marked < >. Press M to compile as a module. In xconfig, click multiple times. A tick means compiled in, a dot means module.

The [….] (eg. [EXPERIMENTAL]) refers to the option name as seen in the .config file. It will be prefaced by CONFIG_ (eg. CONFIG_EXPERIMENTAL=y). Just a little bit of trivia.


Code Maturity Level Options
Prompt for development and/or incomplete code/drivers
[EXPERIMENTAL]
Purpose: You have the option of using experimental (alpha-test) drivers and obsolete drivers.
Suggestion – exclude. However, if you are sure of what you are doing you can include it. This is only for developers or people who have an excellent idea of their hardware configuration. NOTE: you might need to enable this for SATA as explained at the end of the configuration section.

Select only drivers expected to compile cleanly
[CLEAN_COMPILE]
Purpose: If the previous option was selected, then this one appears. Select this
option when you do not even want to see the option to configure known broken drivers.
Suggestion – this option should not even show up, as, in general, the previous option should not have been included.

General setup
Local version - append to kernel release
Purpose: Append an extra string to the end of your kernel version.
This will show up when you type uname.
Select this and type in a string (up to 64 characters)
Suggestion – If you want to customize your OS, including this will really earn you geek points with your techie friends.

Support for paging of anonymous memory
[SWAP]
Purpose: Allows the kernel to have more virtual memory than RAM using swap files or swap devices.
Suggestion – Definitely build this in. If you have loads of RAM you might avoid this, but it is in general a bad idea to try to exist without a swap file. Exclude it on embedded systems, or real time systems only.

System V IPC
[SYSVIPC]
Purpose: This is a feature from the Unix background that Linux has come from. Required for many programs.
Suggestion – build in. There are many common programs that require IPC (inter process communication) provided by this feature.

BSD Process Accounting
[BSD_PROCESS_ACCT]
Purpose: Allows user level programs to specify that process accounting information be stored.
Suggestion – build in.

BSD Process Accounting version 3 file format
[BSD_PROCESS_ACCT_V3]
Purpose: This one show up only if you included the previous option.
Suggestion – leave it out for now.

Sysctl support
[SYSCTL]
Purpose: Allows modification of certain kernel parameters on the fly.
Suggestion – build in. In case of rescue disks it can be left out.

Auditing support
[AUDIT]
Purpose: Required by various kernel subsystems such as SELinux.
Suggestion – build in. It probably won't hurt.

Enable system-call auditing support
[AUDITSYSCALL]
Purpose: Enable low-overhead system-call auditing infrastructure. (appears only if previous option was selected)
Suggestion – might as well build this one in too.

Kernel Userspace Events
[KOBJECT_UEVENT]
Purpose: enables the kernel userspace event layer.
Suggestion – build in.

Kernel .config support
[IKCONFIG]
Purpose: This option enables the complete Linux kernel ".config" file
contents to be saved in the kernel. This information can be extracted from the kernel image file with the script scripts/extract-ikconfig It can also be extracted from a running kernel by reading /proc/config.gz if enabled.
Suggestion – built in. Makes it easier to compile your kernel the next time as you can just load the previous .config and select the changes.

Enable access to .config through /proc/config.gz
[IKCONFIG_PROC]
Purpose: This option enables access to the kernel configuration file through
/proc/config.gz.
Suggestion – build in.
Configure standard kernel features (for small systems)
[EMBEDDED]
Purpose: This is for non standard kernels.
Suggestion – leave it out.

Loadable Module Support

Enable loadable module support
[MODULES]
Purpose: Allows you to build a modular kernel. If you don't want to use modular kernels exclude it. Generally it is a good idea to keep it as you can then build a smaller (and faster) kernel this way.
Suggestion – build in.

Module Unloading
[MODULE_UNLOAD]
Purpose: Enables module unloading facility. All modules may not be able to make use of this feature (though that will not cause any errors).
Suggestion – build in.

Source checksum for all modules
[MODULE_SRCVERSION_ALL]
Purpose: Used by module developers.
Suggestion – leave it out.

Automatic Kernel Module Loading
[KMOD]
Purpose: Allows certain parts of the kernel to automatically load kernel modules using modprobe. It’s probably a good idea to include this unless you are sure of what you are doing.
Suggestion – build in.

Processor type and features

Subarchitecture type – Select PC Compatible (unless you are running non x86 systems)

Processor Family – Your processor should be automatically detected, but do scroll down the list to make sure that it has been selected correctly. Previously AMD64 was detected as K7 rather than K8 (in 2.6.6). Make sure that you choose the correct case (you can safely choose a lower level but never select a configuration higher than your own). Failure to make a proper choice can lead at best to a loss of features and at worst a kernel that fails spectacularly.

Generic x86 support
[X86_GENERIC]
Purpose: Includes Optimizations for processors other than the one selected.
This is required only if you wish to distribute the kernel you have compiled to machines of another architecture.
Suggestion – exclude.

HPET timer support
[HPET_TIMER]
Purpose: Uses the new HPET timer for the kernel's internal timing rather than the venerable 8254 (Anyone who has done a microprocessor techniques course will tell you that the 8254 was made way back in the late 70s and is still in use). It is safe to include this feature as it is only enabled if the platform supports it.
Suggestion – build in.

Provide RTC interrupt
[HPET_EMULATE_RTC]
Purpose: Related to the previous option but there is no documentation on the feature.
Suggestion – leave it out, I guess. It appears to have to do with emulating the real time clock (provided by/using?) the HPET (I infer this from the name).

Symmetric multi-processing support
[SMP]
Purpose: This enables support for systems with more than one CPU (symmetric multiprocessor systems).
Suggestion – if you have more than one processor in your system include this.
This is required to use the hyper-threading feature on processors that support the feature.

Preemptible Kernel
[PREEMPT]
Purpose: Allows low priority processes to be preempted even while in kernel mode (For further explanation read up about the linux process management from a good book).
Suggestion – built in for desktop systems, RTS or embedded.

Preempt The Big Kernel Lock
[PREEMPT_BKL]
Purpose: This option reduces the latency of the kernel by making the
big kernel lock preemptible (what does that mean?). This arises from the previous option.
Suggestion – build in.

Local APIC support on uniprocessors
[X86_UP_APIC]
Purpose: Allows uniprocessors with a local APIC to use this APIC. It can be safely enabled with no slowdown even if it is not present (some of you may have seen an option in the bios dealing with this).
Suggestion – build in.

IO-APIC support
[X86_UP_IOAPIC]
Purpose: this option appears only if you have selected the last one.
Suggestion – Similar to the last option and can be built in. If you have an SMP, it is likely that you will require this.

Machine Check Exception
[X86_MCE]
Purpose: Returns errors to the kernel if the processor detects an error (overheating etc)
Suggestion – built in is a safe option for everyone except Pentium users. Some older Pentiums (Pentium 1s) have a design flaw and report false MCE events. So Pentium users should be cautious while enabling this option. 386s and 486s do not have this feature, so in such cases this option can be excluded (it is still safe to enable it though).

Check for non-fatal errors on AMD Athlon/Duron Intel Pentium 4
[X86_MCE_NONFATAL]
Purpose: Similar to above, but returns errors specific to these processors.
Suggestion – module.

Check for P4 thermal throttling interrupt
[X86_MCE_P4THERMAL]
Purpose: Prints a message whenever the P4 enters thermal throttling.
Suggestion – user's choice.

Toshiba Laptop Support
[TOSHIBA]
Purpose: Useful only on Toshiba Laptops having a Toshiba bios.
Suggestion – exclude unless your system satisfies the above criterion.

Dell Laptop Support
[I8K]
Purpose: Useful only on the Dell Inspiron 8000.
Suggestion – exclude unless your system satisfies the above criterion.

Enable X86 board specific fixups for reboot (X86_REBOOTFIXUPS)
Purpose: This enables chipset and/or board specific fixups to be done
in order to get reboot to work correctly.
Suggestion - Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1. Combination. Others should exclude.

/dev/cpu/microcode – IA32 CPU microcode support.
[MICROCODE]
Purpose: If you say Y here and also to "/dev file system support" in the
'File systems' section, you will be able to update the microcode on
Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
Pentium III, Pentium 4, Xeon etc.
Suggestion – exclude. I have never heard of anyone ever using this.

/dev/cpu/*/msr – Model specific register support
[X86_MSR]
Purpose: Enables privileged processes access to MSRs.
Suggestion – module.

/dev/cpu/*/cpuid – CPU information support
[X86_CPUID]
Purpose: Access to the x86 CPUID instruction.
Suggestion – module.

High memory support
[NOHIGHMEM / HIGHMEM4G / HIGHMEM64G]
Suggestion – If you have not more than 1GB RAM then say “off”.
1- 4 GB then select 4GB
Up to 64 GB then select 64 GB. (Only on systems supporting PAE!)

Allocate 3rd level page tables from high memory.
[HIGHPTE]
Purpose: Setting this option will put user space page tables in high memory.
This avoids the waste of low memory space in systems having large amount of RAM.
Suggestion – build in. This option appears only if you have selected the previous option.

Math Emulation
[MATH_EMULATION]
Purpose: Emulates a math coprocessor on systems which do not have one.
Suggestion – exclude, unless you are running a 386 or 486SX without a coprocessor (unlikely).

MTRR support
[MTRR]
Purpose: Memory Type Range Registers may be used to control access to AGP and PCI buses. Improves performance of video cards.
Suggestion – build in.

Boot from EFI support
[EFI]
Purpose: This option has a meaning only on IA64 systems.
Suggestion – exclude.

Enable seccomp to safely compute untrusted bytecode
[SECCOMP]
Purpose: This kernel feature is useful for number crunching applications
that may need to compute untrusted bytecode during their
execution.
Suggestion – build in.

KingKrool 26 Jun 05 07:24 PM
Power Mangement Options

This section is highly system dependent. I would advise going through each option carefully. Many of the options are only for mobile systems or those running on mobile Pentium or Athlon processors.

Power Management support
[PM]
Purpose: Enables ACPI / APM
Suggestion – build in.

I won't describe the APM/ACPI options. If possible, use ACPI (some older systems will only support APM, others may not even support that). APM is deprecated.

CPU Frequency scaling
[CPU_FREQ]
Purpose: CPU Frequency scaling allows you to change the clock speed of
CPUs on the fly. Note that this driver doesn't automatically change the CPU
clock speed, you need to either enable a dynamic cpufreq governor
after boot, or use a userspace tool.

Enable CPUfreq debugging
[CPU_FREQ_DEBUG]
Suggestion – exclude

CPU frequency translation statistics
[CPU_FREQ_STAT]
Purpose: This driver exports CPU frequency statistics information through sysfs file system
Suggestion – exclude.

Default CPUFreq governor
This option sets which CPUFreq governor shall be loaded at
startup. If in doubt, select 'performance' ie. [CPU_FREQ_DEFAULT_GOV_PERFORMANCE].

Enable 'powersave' governor [CPU_FREQ_GOV_POWERSAVE],
'userspace' governor for userspace frequency scaling [CPU_FREQ_GOV_USERSPACE] and 'conservative' cpufreq governor [CPU_FREQ_GOV_CONSERVATIVE]. In case of desktop systems (excluding AMD systems), enable 'ondemand' cpufreq policy governor [CPU_FREQ_GOV_ONDEMAND] instead of 'conservative'.

CPUFreq processor drivers
Enable the appropriate driver (if any) for your system.

PCI Support
[PCI]
Purpose: Required if the system bus is PCI (as it is on almost all systems from P1 upwards).
Suggestion – build in.

PCI Access Mode – any [PCI_GOANY].

PCI Express support
[PCIEPORTBUS]
Purpose: This automatically enables PCI Express Port Bus support
Suggestion – if you have PCIE on your motherboard, build this in.

Message Signaled Interrupts (MSI and MSI-X)
[PCI_MSI]
Purpose: This allows device drivers to enable MSI (Message Signaled
Interrupts).
Suggestion – exclude for now, it is a new feature.

Legacy proc/pci interface
[PCI_LEGACY_PROC]
Purpose: Legacy support. Newer tools are now in use (ie lspci).
Suggestion – exclude.


PCI device name database
[PCI_NAMES]
Purpose: The kernel contains a database of all known PCI devices.
Disabling this feature replaces the device names by device IDs. It also reduces kernel image size by 80KB (though this memory can be freed at runtime).
Suggestion – build in. If you are creating a boot disk then it can be excluded.

PCI Debugging
[PCI_DEBUG]
Purpose: Produces PCI debug information and writes it to the system log.
Suggestion – exclude.

ISA Support
[ISA]
Purpose: Required only if you have ISA slots in your system.
Suggestion – Most modern systems do not have ISA slots (the Intel 875 may be an exception). It can, therefore, be excluded in such systems.
If your system does have ISA slots then include this as well as all subsequent options that appear on enabling it (except VESA Local Bus priming).

MCA Support
[MCA]
Purpose: Required on systems having Microchannel architecture.
Suggestion – This is supported only on a few systems from IBM. For most systems it should be excluded.

NatSemi SCx200 support
[SCx200]
Suggestion – Required only if you have the National Semiconductir
SCx200 processor. Exclude for most systems.

PCMCIA/ Cardbus Support
Purpose: This sub menu includes several options. It is necessary only on laptops.
Suggestion – exclude on desktop systems. On laptops it should be built in, giving access to several other options not described here.

Executable File Formats

Kernel Support for ELF binaries
Purpose: Required for using Binaries compiled in the ELF format. As the conversion to ELF was started in 1995, this option can be considered critical.
Suggestion – built in.

Kernel support for a.out and ECOFF binaries
Purpose: Required to run certain old binaries which were in the a.out format which is now dead (this has nothing to do with the fact that the default name of all files compiled by gcc is a.out, that was just a convention which is still followed). Needed only if you have really old binries lying around.
Suggestion – exclude. If absolutely necessary then include it as a module.

Kernel support for Miscellaneous binaries
Purpose: Plug wrapper-driven binary formats into the kernel.
Suggestion – built in.
Device Drivers
This is one of the weirdest parts of the configuration, and unfortunately, one which I can't help you with. There are hundreds if not thousands of options, all of them system dependent. I will give you a few tips though.

If you started your configuration using an existing reference .config (whether of the current running kernel or from /arch/... subdirectory) then you should have it a bit easier.

Include Parallel support (module) if you use the parallel port on your PC. Include PC-style hardware under this, but not Multi-IO cards.

Include PnP support – this is important.

Under block devices -
Normal floppy disk support – include
Parallel port IDE device support – exclude (unless you use an external CDROM / HDD connected to your parallel port.
Include Loopback device support (module)
RAM disk support – include
Leave the default values of RAM disk number and size.
Initial RAM disk (initrd) support – include.
Support for Large Block Devices – exclude (do you have a 2 TB disk?)
Packet writing on CD/DVD media – include (module)
ATA over Ethernet support – exclude (most of the time)

Use the CFQ I/O scheduler and exclude the others

ATA/ATAPI/MFM/RLL support – DEFINITELY include unless you have a pure SCSI system. Haven't heard of those for a long time.

Support for SATA [BLK_DEV_IDE_SATA] under Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support – exclude, as it is deprecated. Do not worry if you have SATA hard drives, there is another driver for them.

Include:
IDE/ATAPI CDROM support
IDE/ATAPI FLOPPY support
PCI IDE chipset support
generic/default IDE chipset support
Generic PCI bus-master DMA support
Use PCI DMA by default when available
AMD and nVidia IDE support (nForce users only)
Your SATA controller may be listed here, so include it as well.
For any chipset you don't have – exclude it.

Include SCSI device support. It IS required for USB storage. Also include legacy /proc/scsi/ support and SCSI disk support (for USB storage). Exclude everything else under SCSI and its submenus (except SATA support).

Multiple devices driver support - exclude. Few people use software raid or LVMs on desktops.
I2O support – exclude.

Do not disable networking, it is required even by some non-network programs.
Networking options – leave the defaults, but most people can get rid of Appletalk and IPX.
Choose the correct n/w card option - "Tulip" family network device support is used by NC100 based cards.

Do you have IR ports, Token Ring, Bluetooth, FDDI, 10Gbps networks? Use common sense and exclude everything in these sections.

Wireless LAN – include only on systems with a wireless card of some type. You will still need drivers.

WAN interfaces support – exclude. No one connects to a WAN using an interface card on a desktop. Very rare.

ISDN support – do you use ISDN? I don't, nor do I know anyone who does anymore.

Character devices -
do you need non standard serial support? – mostly no.
Intel/AMD/VIA HW Random Number Generator support – yes if you have an i8xx series chipset. Presumably it should work for i9xx series as well, but I can't be sure of that.
/dev/nvram support – include.
/dev/agpgart – build in (module).

Lookout for your chipset driver for AGP support in character devices and make sure to include it (all others can then be excluded). Specifically, there is support for i865 and nforce 1 and 2, SIS and VIA, apart from several others (If you have nforce3 you can try nforce2 driver).

If you have a Radeon then include its driver under Direct Rendering Manager of Character Devices.

Configure Graphics support carefully. It can cause problems otherwise.

Under sound, select ALSA, not OSS (which is deprecated).
In ALSA, under PCI devices, select your soundcard. There is support for quite a few soundcards – Aureal, Audigy, SBLive, AC97, Intel HD Audio and many others.

USB support should also be configured carefully. Most people now have USB 2.0, so it along with USB 1.1 should be selected. Include USB storage if you are likely to use a pen drive.

Remember this section is largely about common sense. If you don't have need for a particular feature, or do not have certain hardware, then in most cases it is safe to switch it off. This however, does not apply to the networking and SCSI. Be careful there.

File Systems
This is another large section, so I'll just mention whether you should include an option or not.

Second Extended fs support – build in for Redhat/Fedora etc distros.
EXT2 extended attributes – exclude.
EXT3 journalling file system support - build in for Redhat/Fedora etc distros.
EXT3 extended attributes – exclude.
(extended attributes must be included if you want to use SELinux or the like)
JBD debugging support – exclude.
Reiserfs support – include on SUSE, Mandrake and others.
JFS support – exclude.
XFS support – exclude.
Minix filesystem support – exclude.
ROM filesystem support – exclude.
(Some people might need these, but if you are such a person, you will know how to configure them)
Quota support – exclude. Only needed if you want to set limits on user disk usage. Again, an advanced option, not present on most home PCs or single user desktops.
Kernel automounter support – exclude.
Kernel automounter support v4 – exclude. Needed only on large networks.

CD/DVD ROM filesystems – use built in for all the options in the submenu.
DOS/FAT/NT Filesystems --->
MSDOS fs suport – exclude (usually, except in cases where linux is mounted from a DOS partition).
VFAT fs support – include.
NTFS support – build in.
NTFS debugging support – exclude.
NTFS write support – exclude. It doesn't do much.
(The above options should actually be included as modules, but I would recommend not doing so the first time. With experience you will learn which features should generally be compiled as modules and then these can be configured accordingly).

Pseudo Filesystems-->
/proc file system support – include.
/dev/pts extended attributes – exclude. Again, you will know if you need it.
Virtual memory file system support – include.
HugeTLB filesystem support – exclude. Not sure what this does.

Miscellaneous filesystems-->
All the options in the submenu can generally be excluded. They are not commonly used on Linux/Windows dual boot systems.

Network filesystems support-->
Again, all these options can usually be excluded. They are required only on networked computers. If you are on a networked system then your administrator should be able to tell you which filesystems are required. Accordingly support can be compiled in. Possibly you can include SMB file system support.

Partition types--> Only two options are to be included:
1. Advanced partition selection.
2. PC BIOS support.
If you use dynamic disks in Windows 2000 or later, then you should also include Windows Logical Disk Manager support.

Native Language Support--> exclude all except USA/Canada and NLS ISO 8859-1 + NLS ISO 8859-15. This is to do with codepages (non-english filenames, not contents).

Kernel Hacking
All the options in this menu are advanced features. It is best to exclude them from the kernel.

Security Options
Enable different Security models
Purpose: This allows you to use security models other than the default linux security model.
Suggestion – exclude. You may want to include this however if you are interested in using SELinux (security enhanced).
Enable access key retention support – exclude.

Cryptographic Options
It is safe to include all these options as modules. Don't build them in, otherwise your kernel size will increase dramatically. Compiling these options into the kernel is recommended only if you use them very frequently (e.g. All your documents are encrypted using one of these algorithms).
Even if you don't include them, third party tools can provide these services.

Library Routines
Both options can be included safely.

After you are finished save the file and proceed to the Post Configuration section given earlier.

The above configuration procedure was on the 32 bit system, when you try this on a 64 bit system, different options are available.

-The processor options are different.
-There are different ACPI options.
-CPU frequency scaling now has K8 PowerNow! (Cool n Quiet)
-Funnily enough, there is no option for initrd. Add it in manually to the .config file as:
CONFIG_BLK_DEV_INITRD=y
-File formats: there is no longer an a.out format in the 64 bit world. However, there is IA32 emulation, as well as IA32 a.out emulation.

Unfortunately, I was unable to get the kernel up and running on FC3 (64 bit). FC3 has some difficulties which I was unable to get around. For one, it is necessary to make an initrd (initial RAM disk). And there was no option in the kernel to enable it. Even after putting it in manually I was unable to boot up. Seems like some bug. If anyone has any success (on a 64 bit FC3) please do post here.
Funnily, I used the 64 bit kernel, with a 32 bit Distro (CentOS 3.6) and it booted up properly.

If you want to enable SATA then try this (it did not work on the 32 bit FC1, but did on the 64 bit kernel + CentOS combo – CentOS root was located on the SATA hdd):

In code maturity options, include “Prompt for development and/or incomplete code/drivers”, but exclude “Select only drivers expected to compile cleanly”. Then under ATA/ATAPI/MFM/RLL include support for your SATA chipset (if listed). Then go to SCSI, enable support for SCSI hard disks. Got to SCSI low level drivers, enable SATA hard disks and enable support for your SATA chipset/controller listed under that (sata_sil, sata_nv, etc.).

Well that's it! Enjoy!!!!