Kernel options meaning ???

td0l2 · 07-04-2004, 09:04 PM

Hi all,
I would like to know the options meaning of Kernel item when i use "make menuconfig". Since i want to make a small size of kernel, understanding those items help me to do so.

Thanks.

heema · 07-04-2004, 09:10 PM

when u use menuconfig , u will find a help button to tell you what is that u selected

td0l2 · 07-04-2004, 10:42 PM

yes ! you are right !!
But i want to know that which options are used for creation of basic kernel. I would like to create a small kernel as possible.

Are there any website or info teaching me to select which option should be chosen ??

td0l2 · 07-05-2004, 09:39 AM

Does anyone help ??

I want to create a small size of kernel as possible. Which options do i need to select ??

The kernel just boot up !

Oliv' · 07-05-2004, 10:41 AM

Hi,

According to me the best way to learn is to test by yourself

Cause according to your hardware and the config you want (network or not... ), the options change...
And the other problem is to know if you want a complete tiny kernel or a tiny kernel which will load modules at boot time...

Oliv'

td0l2 · 07-05-2004, 08:22 PM

Yes, you are right !
I think if kernel booting up must have essential component selected on the menuconfig.
Both loading and performance of tiny kernel are better than that of larger one.
My target is to create a "TINY KERNEL" which can be stored in the floppy.
( my creation latest one has 1.8MByte which can NOT be stored in the floppy )

Can anyone help me ???

amosf · 07-05-2004, 10:51 PM

Why do you want a tiny kernel? Why does it need to fit on a floppy?

Kernel size will have liitle to do with boot up time really, unless your seconds really count???

td0l2 · 07-06-2004, 02:07 AM

Thanks for replies !

Smaller size the kernel is, better performance the linux is !!

My target is to create a "TINY KERNEL" and know about the mininal options chosen in menuconfig.

Oliv' · 07-06-2004, 07:22 AM

Quote:

my creation latest one has 1.8MByte which can NOT be stored in the floppy

OK but that's an uncomprssed kernel... because mine's is 2.4M but when it's compressed it's only 857k

Cause I don't know if it's possible to make a boot floppy with an uncompressed kernel... as a matter of fact, the floppy must store a kernel and files to boot from floppy (for example syslinux or something like that)

Oliv'

td0l2 · 07-06-2004, 07:53 PM

Oh !! my latest kernel is using "bzImage" which is compressed. But the size has 1.8MByte.
What optons do you choose in menuconfig ??
What is the minimal selection of menuconfig ??
Would you mind posting your config on this forum ??

Oliv' · 07-07-2004, 07:59 AM

Hi,

here is my config (my kernel is 2.4.26 patched low-latency):

Code:

CONFIG_X86=y
CONFIG_UID16=y

#
# Code maturity level options
#
CONFIG_EXPERIMENTAL=y

#
# Loadable module support
#
CONFIG_MODULES=y
CONFIG_MODVERSIONS=y
CONFIG_KMOD=y

#
# Processor type and features
#
CONFIG_LOLAT=y
CONFIG_MK6=y
CONFIG_X86_WP_WORKS_OK=y
CONFIG_X86_INVLPG=y
CONFIG_X86_CMPXCHG=y
CONFIG_X86_XADD=y
CONFIG_X86_BSWAP=y
CONFIG_X86_POPAD_OK=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_X86_L1_CACHE_SHIFT=5
CONFIG_X86_ALIGNMENT_16=y
CONFIG_X86_HAS_TSC=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_X86_MCE=y
CONFIG_NOHIGHMEM=y
CONFIG_MATH_EMULATION=y
CONFIG_X86_UP_APIC=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_TSC=y
#
# General setup
#
CONFIG_NET=y
CONFIG_PCI=y
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y
CONFIG_ISA=y
CONFIG_PCI_NAMES=y
CONFIG_SYSVIPC=y
CONFIG_BSD_PROCESS_ACCT=y
CONFIG_SYSCTL=y
CONFIG_KCORE_ELF=y
CONFIG_BINFMT_AOUT=y
CONFIG_BINFMT_ELF=y
CONFIG_BINFMT_MISC=y
CONFIG_PM=y

#
# Plug and Play configuration
#
CONFIG_PNP=y
CONFIG_ISAPNP=y

#
# Block devices
#
CONFIG_BLK_DEV_FD=y
CONFIG_BLK_DEV_LOOP=y

#
# Networking options
#
CONFIG_PACKET=y
CONFIG_PACKET_MMAP=y
CONFIG_FILTER=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_MULTICAST=y

#
# ATA/IDE/MFM/RLL support
#
CONFIG_IDE=y

#
# IDE, ATA and ATAPI Block devices
#
CONFIG_BLK_DEV_IDE=y
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_IDEDISK_MULTI_MODE=y
CONFIG_BLK_DEV_IDECD=y
CONFIG_BLK_DEV_CMD640=y
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_IDEDMA_AUTO=y

#
# SCSI support
#
CONFIG_SCSI=m
CONFIG_BLK_DEV_SD=m
CONFIG_SD_EXTRA_DEVS=40

#
# SCSI low-level drivers
#

CONFIG_SCSI_AIC7XXX=m
CONFIG_AIC7XXX_CMDS_PER_DEVICE=32
CONFIG_AIC7XXX_RESET_DELAY_MS=15000
CONFIG_AIC7XXX_DEBUG_MASK=0

#
# Network device support
#
CONFIG_NETDEVICES=y

#
# Ethernet (10 or 100Mbit)
#
CONFIG_NET_ETHERNET=y
CONFIG_NET_PCI=y
CONFIG_EEPRO100=y


CONFIG_PPP=y
CONFIG_PPP_FILTER=y
CONFIG_PPP_ASYNC=y
CONFIG_PPP_DEFLATE=y
CONFIG_PPP_BSDCOMP=y

#
# Character devices
#
CONFIG_VT=y
CONFIG_VT_CONSOLE=y
CONFIG_SERIAL=y
CONFIG_UNIX98_PTYS=y
CONFIG_UNIX98_PTY_COUNT=256

#
# Mice
#
CONFIG_MOUSE=y
CONFIG_PSMOUSE=y

#
# Watchdog Cards
#
CONFIG_RTC=y


#
# Ftape, the floppy tape device driver
#
CONFIG_AGP=y
CONFIG_AGP_NVIDIA=y

#
# Direct Rendering Manager (XFree86 DRI support)
#
CONFIG_DRM=y
CONFIG_DRM_NEW=y

#
# Multimedia devices
#
# CONFIG_VIDEO_DEV is not set

#
# File systems
#

CONFIG_AUTOFS4_FS=y
CONFIG_EXT3_FS=y
CONFIG_JBD=y
CONFIG_FAT_FS=y
CONFIG_VFAT_FS=y
CONFIG_TMPFS=y
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
CONFIG_PROC_FS=y
CONFIG_DEVFS_FS=y
CONFIG_DEVFS_MOUNT=y
CONFIG_DEVPTS_FS=y
CONFIG_EXT2_FS=y

#
# Partition Types
#

CONFIG_MSDOS_PARTITION=y
CONFIG_NLS=y

#
# Native Language Support
#
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_CODEPAGE_850=m
CONFIG_NLS_ISO8859_15=m

#
# Console drivers
#
CONFIG_VGA_CONSOLE=y
CONFIG_VIDEO_SELECT=y

#
# Frame-buffer support
#
# CONFIG_FB is not set

#
# Sound
#
CONFIG_SOUND=y
CONFIG_SOUND_VIA82CXXX=y

#
# USB support
#
# CONFIG_USB is not set

#
# Support for USB gadgets
#
# CONFIG_USB_GADGET is not set

#
# Bluetooth support
#
# CONFIG_BLUEZ is not set

#
# Kernel hacking
#
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_SLAB=y
CONFIG_LOG_BUF_SHIFT=0

#
# Cryptographic options
#
CONFIG_CRYPTO=y
CONFIG_CRYPTO_MD5=m
CONFIG_CRYPTO_SHA1=m
CONFIG_CRYPTO_SHA256=m
CONFIG_CRYPTO_SHA512=m
CONFIG_CRYPTO_DES=m
CONFIG_CRYPTO_BLOWFISH=m
CONFIG_CRYPTO_AES=m
CONFIG_CRYPTO_CAST5=m
CONFIG_CRYPTO_DEFLATE=m

#
# Library routines
#
# CONFIG_CRC32 is not set
CONFIG_ZLIB_INFLATE=y
CONFIG_ZLIB_DEFLATE=y

Note that there are still useless things like VFAT support or Kernel hacking support or options like CONFIG_BINFMT_AOUT or CONFIG_BINFMT_MISC...

Oliv'

td0l2 · 07-07-2004, 08:57 PM

Thanks Oliv'.

Would you mind pointing which option is useless ??
You know ! I want to have some listing of minimal options for creation of kernel.
Also, would you please explain what they are ?? and Any site provide such infomation ??

Oliv' · 07-11-2004, 07:07 AM

Hi,

Quote:

Would you mind pointing which option is useless ??

It depends on your hardware configuration... In fact to build a small kernel you have to perfectly know your hardware... If you exactly know that, it should be easy with "help" menu in the kernel config... And if you find that this menu is not complete enough, you can also read doc available in /usr/src/linux/Documentations directory.
And the best way to know if an option is essential or not is to try to compile a kernel without this option

Oliv'

ppuru · 07-11-2004, 08:57 AM

also depends on the type of functionality you are looking in your kernel.

e.g. you can completely disable all SCSI options, sound options, filesystems you do not want to support, net cards you do not expect to use ... just to give you an idea