Comparison of operating system kernels

From Wikipedia, the free encyclopedia

Jump to: navigation, search

A kernel is the core component of every computer operating system. While kernels are highly technical in nature, and may be hidden from the user under many layers of software and applications, they do have distinguishing or characteristic features, such as computer architecture, design goals, as well as the more practical features that they provide. A direct comparison of operating system kernels can highlight these design choices, and provide insight into different niches and the evolving technology of kernels.

Contents

[edit] Comparison criterion

The following tables compare general and technical information for a number of widely used and currently available operating system kernels. Please see the individual products' articles for further information.

Even though there is a large number and variety of available Linux distributions, all of these kernels are grouped under a single entry in these tables, due to differences being of the patch level. See comparison of Linux distributions for a detailed comparison. For Linux distributions that have highly modified kernels, for example Real-time computing kernels, they should be listed separately. There are also a wide variety of minor BSD operating systems, many of which can be found at Comparison of BSD operating systems.

The tables specifically do not include subjective viewpoints on the merits of each kernel or operating system. For this kind of information, please see operating system advocacy.

[edit] Feature overview

The major contemporary general-purpose kernels are shown in comparison. Only an overview of the technical features is detailed.

Kernel name Used in Creator Executable
format
(also see
section
below)
Type Integrated firewall SMP support Multiple architecture
support
(also see
section below).
Multitasking Virtualization Security Profiling/Debugging Soft real-time support Hard real-time support
Agnix [1] ? ? ? ? ? ? ? Yes ? ? ? ? ?
Amiga Exec AmigaOS Commodore International/Carl Sassenrath HUNK Exokernel (atypical)[1] No No No Yes ? ? ? ? Yes
Amiga Exec SG (2nd Generation) AmigaOS 4 Hyperion Entertainment under
license of Amiga Inc.
ELF (Can
run 68000
code Hunk)
microkernel (atypical) No No No Yes ? ? ? ? ?
DragonFly BSD kernel [2] DragonFly BSD Matt Dillon ELF, others - platform dependent hybrid IPFilter, Ipfirewall,
PF
Yes Yes Yes ? ? ? ? ?
FreeBSD kernel FreeBSD

Debian GNU/kFreeBSD Gentoo/FreeBSD

The FreeBSD Project ELF, others - platform dependent monolithic IPFilter, Ipfirewall,
PF
Yes Yes Yes chroot, jail POSIX ACL[2], TrustedBSD MAC, OpenBSM KDB, DDB, KGDB, DTrace, hwpmc Yes ?
GNU Hurd [3] Bee GNU/Hurd

Debian
GNU/Hurd

GNU Project/Free Software Foundation ELF microkernel ? No No Yes ? ? ? ? ?
GNU Mach [4] ? GNU Project/Free Software Foundation ? microkernel ? No No Yes ? ? ? ? ?
Inferno kernel Inferno Bell Labs / Vita Nuova Holdings ? virtual machine ? Yes Yes Yes ? ? ? ? ?
L4 L4 Jochen Liedtke ? microkernel ? Yes Yes Yes ? ? ? ? ?
Linux kernel [5] Linux Linus Torvalds ELF, others monolithic netfilter/
iptables
Yes Yes Yes cgroups, chroot, Lguest, Xen, KVM, kvm-lite POSIX ACL, POSIX Capabilities, keyctl, LSM(SELinux, SMACK, TOMOYO Linux, AppArmor) Oprofile, kprobe, SystemTap, jprobe, ftrace, KDB, KGDB, Kernel marker, perf tools CONFIG_PREEMPT (CONFIG_PREEMPT_RT Patch)
Mach [6] NextStep and OpenStep Carnegie Mellon University Mach-O microkernel ? ? ? ? ? ? ? ? ?
Minix 3 [7] Minix 3 Andrew S. Tanenbaum a.out
microkernel No No No Yes No Unix permissions Call profiling, statistical profiling, Minix Debugger (mdb) No No
MkLinux [8] ? OSF Research Institute and Apple Computer ? microkernel ? ? ? ? ? ? ? ? ?
NetBSD kernel NetBSD

Debian GNU/NetBSD

The NetBSD Project ELF, others - platform dependent monolithic IPFilter

PF

Yes Yes Yes Xen, chroot kauth DDB, KGDB, tprof POSIX real-time scheduling extensions Kernel preemption
NetWare kernel Novell NetWare Novell NLM hybrid Yes Yes No Yes ? ? ? ? ?
OpenBSD kernel OpenBSD OpenBSD developers ELF, others - platform dependent monolithic PF Yes Yes Yes ? ? ? ? ?
Plan 9 kernel Plan 9 from Bell Labs Bell Labs ? hybrid ipmux Yes Yes Yes ? ? ? ? ?
ReactOS kernel ReactOS ReactOS Foundation PE, others? hybrid ? ? ? Yes ? ? ? ? ?
Rockbox kernel Rockbox The Rockbox Project ? ? ? ? Yes ? ? ? ? ? ?
SunOS kernel SunOS Sun Microsystems a.out
monolithic ? Yes Yes Yes ? ? ? ? ?
Solaris kernel Solaris Operating System,

Nexenta OS

Sun Microsystems ELF (32-bit
only until
Solaris 7)
monolithic IPFilter Yes Yes Yes Zones ? DTrace ? ?
Trix ? Massachusetts Institute of Technology ? monolithic ? ? ? ? ? ? ? ? ?
Windows NT kernel [9] Windows NT, 2000,
XP, 2003, Vista, Windows 7
Microsoft PE, others? hybrid Yes Yes Yes Yes ? ? ? ? ?
XNU (Darwin kernel) [10] Mac OS X

OpenDarwin GNU/Darwin

Apple Computer Mach-O hybrid Ipfirewall Yes Yes Yes ? ? DTrace ? ?
SPARTAN kernel (HelenOS kernel) [11] HelenOS Jakub Jermar ELF microkernel ? Yes Yes Yes ? ? ? ? ?
Kernel name Used in Creator Executable
format
(also see
section
below)
Type Integrated firewall SMP support Multiple architecture
support
(also see
section below).
Multitasking Virtualization Security Profiling/Debugging Soft real-time support Hard real-time support

[edit] Transport protocol support

Kernel Name TCP UDP SCTP DCCP
FreeBSD kernel Yes Yes Yes No
Linux kernel Yes Yes Yes Yes
Windows NT kernel Yes Yes No ?

[edit] In-kernel server support

Kernel Name HTTP FTP NFS CIFS Name server transport-layer load balancer application-layer load balancer 9P SSL proxy
Linux kernel (TUX web server patch) (TUX web server patch) knfsd Yes ? IP Virtual Server (KTCPVS) (patch available) No
Windows NT kernel HTTP.sys ? ? ? ? ? ? No ?
Solaris kernel ? ? ? Yes[3] ? Integrated Load Balancer (In Progress) ? ? KSSL

[edit] Binary format support

A comparison of OS support for different binary formats (executables):

Kernel Name a.out ECOFF ELF FDPIC
ELF
binaries
(mmu less)
flat
binaries
(superH)
HUNK Mach-O Misc
(wrapper
based,
like
interpreters)
PE SOM
(PA-RISC,
HP-UX)
NLM PEF
Amiga Exec No No Yes[4] No No Yes No No No No ? ?
Linux kernel Yes Yes Yes Yes Yes No No Yes Some[5] Yes ? No
MINIX 3 Yes No No No No No No No No No No No
ReactOS kernel ? ? ? ? ? ? ? ? Yes ? ? ?
Solaris kernel Yes[6] No Yes[7] No No No No No Some[8] No ? ?
Windows NT kernel No No No No No No No No Yes No No No
XNU No No No No No No Yes No No No No Yes

[edit] File system support

Physical file systems:

Kernel Acorn ADFS Amiga FFS BeFS BFS cramfs EFS ext2 ext3 ext4 FAT FreeVxFS HFS HFS+ HPFS ISO 9660 JFFS JFFS2 JFS Minix fs NSS NTFS OCFS QNX4 FS System V FS UDF UFS XFS ZFS ReiserFS Reiser4 Btrfs HAMMER Tux3 exFAT
FreeBSD kernel No No No No No No Yes Yes Yes Yes No No No No Yes No No No No No limited write No No No Yes Yes read only Yes read only No No No No ?
Linux kernel Yes
[9]
Yes read only Yes Yes read only Yes Yes Yes Yes read only Yes Yes Yes Yes Yes Yes Yes Yes Yes limited write
[10]
Yes Yes
[9]
[11]
write support? Yes Yes
[9]
Yes No Yes Yes Yes No Yes (experimental patch is available[12])
MINIX 3 No No No No No No No No No Tools available, cannot mount No No No No Tools available, cannot mount No No No Yes No No No No No No No No No No No No No No No
NetWare kernel No No No No No No No No No Yes No No No No Yes No No No No Yes No No No No Yes No No No No No No No No ?
ReactOS kernel No No No No No No No No No Yes[13] No No No No Yes[13] No No No No No No No No No Yes[13] No No No No No No No No No
Solaris kernel ? ? ? ? ? ? Yes ? ? Yes ? ? ? ? Yes ? ? ? ? No No ? ? ? Yes Yes ? Yes No No No No No ?
Windows NT kernel ? ? ? ? ? ? Yes
[14]
Yes
[15]
? Yes ? Yes
[15]
Yes
[15]
? Yes ? ? ? ? No Yes ? ? ? Yes ? ? No No No No No No Yes
XNU No No No No No No Yes
[16]
Yes
[16]
No Yes No Yes Yes No Yes No No No No No limited write No No No Yes Yes No read only No No No No No ?

[edit] Supported CPU architectures

kernel DEC ARM Holdings HP Intel MIPS Technologies ? IBM Renesas Electronics Sun Microsystems Intel Motorola Analog Devices Intel Xilinx Renesas Electronics Tensilica Axis Communications Fujitsu Atmel Panasonic Hyperstone Altera Intel WDC
PDP-11 VAX Alpha ARM PA-RISC IA-64 MIPS PowerPC PowerPC
970
System/
390
H8300 M16C M32R SuperH SPARC x86 x86-64 m68k Blackfin (nommu) i960 MicroBlaze 78K V850 Xtensa ETRAX CRIS FR-V AVR32 MN10300 E1 (nommu) Nios (nommu) Nios II Intel 8086 (used in pc98) Intel 80286 WDC 65C816
mmu nommu mmu nommu mmu nommu 32-bit 64-bit nommu mmu nommu mmu nommu mmu nommu
Linux kernel No No Yes Yes Yes Yes Yes Yes ? Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes No (dropped after uClinux-2.0.x) Yes No No (dropped in 2.6.x) Yes Yes Yes Yes Yes Yes No (dropped after uClinux-2.4.x) No (dropped after uClinux-2.4.x) No No No (dropped in 2.6.x) No No
DragonFly BSD kernel ? ? No No No No No No No No No No ? ? ? No No No No No Yes No No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
FreeBSD kernel ? ? Yes Yes ? No Yes No No Yes No No ? ? ? No No No Yes ? Yes Yes No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Yes ? ?
MINIX 3 No ? No In progress ? No No In progress ? No No No No ? No No No No No No Yes In progress No No No No No ? No No No No No No No No No No No ? ? No
NetBSD kernel Yes ? Yes Yes No[17] Yes Yes Yes No[17] Yes No No ? ? ? Yes No[17] Yes Yes No[17] Yes Yes Yes No[17] ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
NetWare kernel ? ? No No No No No No No No No No ? ? ? No No No No No Yes No No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
OpenBSD kernel ? ? Yes Yes ? Yes No Yes ? Yes No No ? ? ? Yes ? Yes Yes ? Yes Yes Yes Yes ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Rockbox kernel ? ? ? Yes ? ? ? ? ? ? ? ? ? ? ? Yes ? ? ? ? ? ? Yes ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Solaris kernel ? ? No No No No No No No No No No ? ? ? No No Yes Yes ? Yes Yes No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Windows NT kernel ? ? NT 5.0 RC1 and below only No ? No Yes NT 4.0 and below only ? NT 3.51 and NT 4.0 only No No ? ? ? No No No No No Yes Yes No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Windows CE kernel No ? No Yes ? No No Yes ? No No No No ? No Yes ? No No No Yes ? No No No No No ? No No No No No No No No No No No No No No
XNU ? ? No Yes ? No No No No Yes Yes[18] No ? ? ? No No No No No Yes Yes[18] No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
SPARTAN kernel ? ? No Yes ? No Yes Yes ? Yes In Progress No ? ? ? No No No Yes ? Yes Yes No No ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
FreeRTOS kernel ? ? ? ? Yes ? ? ? ? Yes ? ? ? ? ? ? ? ? ? ? ? ? ? ? Yes ? Yes Yes Yes ? ? ? ? Yes ? ? ? ? Yes ? ? ?

[edit] Supported kernel execution environment

Kernel name Linux Darwin Windows NT kernel FreeBSD NetBSD Solaris OSF/1 Amiga Unix SunOS BSDI IBCS2 systems IRIX Ultrix NDIS SVR4
Linux Yes No No No No No No No No No No No No No No
NetBSD Yes[19] No? [12]? No? [13]? Yes[19] Yes Yes[19] Yes[19] Yes[19] Yes[19] Yes[19] Yes[19] Yes[19] Yes[19] Yes [14] Yes
OpenBSD Yes No No Yes Yes Yes No No Yes ? ? ? ? No Yes
FreeBSD Yes[20] No No Yes No No No No No No No No No Yes[20] Yes[20]
Windows NT kernel No No Yes No No No No No No No No No No No No
ReactOS kernel No No Yes No No No No No No No No No No No No
Kernel name Linux Darwin Windows NT kernel FreeBSD NetBSD Solaris OSF/1 Amiga Unix SunOS BSDI IBCS2 systems IRIX Ultrix NDIS SVR4

[edit] Supported cipher algorithms

This may be usable on some situations like file system encrypting.

Kernel name DES AES Blowfish Triple DES Serpent Twofish CAST-128 DES-X IDEA RC2 RC5 SEED Skipjack TEA XTEA CAST-256 RC4 Camellia Anubis KHAZAD Salsa20 FCrypt
Linux Yes Yes Yes Yes Yes Yes Yes ? ? ? ? Yes ? Yes Yes Yes Yes Yes Yes Yes Yes Yes
Kernel name DES AES Blowfish Triple DES Serpent Twofish CAST-128 DES-X IDEA RC2 RC5 SEED Skipjack TEA XTEA CAST-256 RC4 Camellia Anubis KHAZAD Salsa20 FCrypt

[edit] Supported compression algorithms

This may be usable on some situations like compression file system.

Kernel name Deflate zlib LZO
Linux Yes Yes Yes
Kernel name Deflate zlib LZO

[edit] Supported hash algorithms

Kernel name CRC32c MD4 MD5 SHA-1 SHA-256 SHA-512 Michael MIC RIPEMD-128 RIPEMD-160 RIPEMD-256 RIPEMD-320 Tiger Whirlpool MD2 GOST LASH-160 LASH-256 LASH-384 LASH-512
Linux Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes ? ? ? ? ? ?
Kernel name CRC32c MD4 MD5 SHA-1 SHA-256 SHA-512 Michael MIC RIPEMD-128 RIPEMD-160 RIPEMD-256 RIPEMD-320 Tiger Whirlpool MD2 GOST LASH-160 LASH-256 LASH-384 LASH-512

[edit] Supported Bluetooth protocols

Kernel name ACL SCO LMP HCI L2CAP BNEP RFComm. SDP TCP AVTCP AVDTP OBEX CMTP HIDP HCRP CAPI PPP
Linux ? Yes ? Yes Yes Yes Yes ? ? ? ? ? Yes Yes ? ? ?
FreeBSD kernel ? ? ? Yes Yes ? Yes Yes ? ? ? ? ? ? ? ? ?
Kernel name ACL SCO LMP HCI L2CAP BNEP RFComm. SDP TCP AVTCP AVDTP OBEX CMTP HIDP HCRP CAPI PPP

[edit] See also

[edit] Footnotes

  1. ^ The Amiga hardware lacked support for memory protection, so the strong isolation goals of the microkernel design could not be achieved.[citation needed]
  2. ^ http://www.freebsd.org/doc/en/books/handbook/fs-acl.html
  3. ^ OpenSolaris Project Weaves CIFS Server Into the Solaris Kernel
  4. ^ AmigaOS up to version 3.9 could use the ELF format for PowerPC executables and libraries through ppc.library, also known as PowerUP. AmigaOS 4, uses ELF as its native executable format.
  5. ^ The Linux kernel can recognize PE binaries through binfmt_misc and run them using Wine
  6. ^ to support SunOS 4.x binaries
  7. ^ including a Linux compatibility option
  8. ^ The Solaris kernel can PE using Wine
  9. ^ a b c experimental and dangerous write support
  10. ^ The only supported operation is overwriting existing files, without changing the file length so a loop file on a ntfs volume can be written; better write support can be achieved through ntfs-3g, although that is a FUSE filesystem and therefore not strictly a kernel feature
  11. ^ write support currently broken
  12. ^ Fat64 / exFat fs and Linux
  13. ^ a b c Version Status - ReactOS
  14. ^ additional driver needed - see http://www.fs-driver.org/
  15. ^ a b c additional driver needed
  16. ^ a b Third party module required. Mac OS X Kernel Module available here
  17. ^ a b c d e NetBSD Projects - Support for MMU-less systems
  18. ^ a b kernel is 32-bit code; 64-bit user-mode code is supported
  19. ^ a b c d e f g h i j NetBSD Binary Emulation
  20. ^ a b c Linux emulation in FreeBSD - 2 A look inside...