லினக்ஸ் கரு
கட்டற்ற கலைக்களஞ்சியமான விக்கிபீடியாவில் இருந்து.
லினக்ஸ் என்பது திறந்த ஆணைமூல இயங்குதளமான GNU/Linux இனது அடிப்படை மென்பொருளான கரு (Kernel) இனது பெயராகும். இம்மென்பொருள் லினஸ் டோர்வால்ஸ் என்பவரது முயற்சியால் 1991ம் ஆண்டு உருவாக்கப்பட்டு தற்போது உலகம் எங்கும் பரந்திருக்கும் வல்லுனர்களால் படிப்படியாக வளர்த்தெடுக்கப்பட்டுவருகிறது.
பொதுவான பயன்பாட்டில் லினக்ஸ் என்ற சொல் GNU/Linux இயங்குதளத்தை குறிக்க பயன்படுத்தப்பட்டாலும் அவ்வாறு பயன்படுத்துவது அடிப்படையில் தவறானதாகும்.
முதன் முதலில் இது Intel 80386 processor என்பதற்கு உருவாக்கப்பட்டவை. ஆனால் அது மற்ற பிளாட்ஃபாம்களிலும் வேலை செய்யும். அது C மற்றும் GNU C மொழியின் நீச்சியின் உதவியோடும் மற்றும் assembly language (in the GNU Assembler's "AT&T-style" syntax) உதவியோடும் எழுதப்பட்டதாகும்.
இது GNU General Public License எனப்படும் காப்புரிமையின் கீழ் உருவாக்கப்பட்டவை. அதனால் லின்க்ஸின் source code free software ஆகும்.
கெர்னல் என்பது சிறந்து விலங்கும் GNU/Linux ஆபிரேட்டிங் சிஸ்டமின் மூலதன மென்பொருளாகும். Distributions of software based on this kernel are called GNU/Linux distributions.
பொருளடக்கம் |
[தொகு] வரலாறு
The project was launched in 1991 with a famous post to the Usenet newsgroup comp.os.minix that includes this sentence:
- "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones..." [1]
At the time, the GNU project had created many of the components required for a free operating system, but its own kernel, the GNU Hurd, was incomplete and unavailable. The BSD operating system had not yet freed itself from legal encumbrances. This left a space for the Linux kernel to fill, and despite the limited functionality of the early versions it rapidly accumulated developers and users. Early on, Minix hackers contributed code and ideas to the Linux kernel, and today it has received contributions from thousands of programmers.
Originally, "Linux" was only the name of the kernel. The term "kernel" properly refers to the low-level system software that provides a hardware abstraction layer, disk and filesystem control, multi-tasking, load-balancing, networking and security enforcement. A kernel is not a complete operating system (as the term is usually understood). A complete system built around the Linux kernel is commonly known as the Linux operating system, although some prefer to call the system GNU/Linux and there is some controversy on the point. People often confuse the kernel with the operating system, leading to many mistaken notions, e.g. the idea that Torvalds wrote or coordinates other parts of the system than the kernel.
[தொகு] காலக்கோடு
- ஏப்ரல் 1991 - இலைனஸ் டோர்வால்ட்ஸ் தமது 21-ஆம் வயதில் இயங்குதளத்திற்கான (Operating System) தனது சிறிய என்னங்களில் 386 கோர்பிற்கான (Assembly) 'செயல்மாற்றி' (Task Switcher) மற்றும் கடைமுகவு (Terminal) இவற்றிற்கான பனிகளை தொடங்குகிறார்.
- 25 ஆகஸ்ட் 1991 - இலைனஸ் தமது நிரல்களை கொம்ப்.ஓஎஸ்.மினிக்ஸ் செய்திக்குழுவில் பதிவேற்றுகிறார்: [2]
-
- "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since april, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).
-
- I've currently ported bash(1.08) and gcc(1.40), and things seem to work. This implies that I'll get something practical within a few months [...] Yes - it's free of any minix code, and it has a multi-threaded fs. It is NOT portable (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that's all I have :-(.
-
- [...] It's mostly in C, but most people wouldn't call what I write C. It uses every conceivable feature of the 386 I could find, as it was also a project to teach me about the 386. As already mentioned, it uses a MMU, for both paging (not to disk yet) and segmentation. It's the segmentation that makes it REALLY 386 dependent (every task has a 64Mb segment for code & data - max 64 tasks in 4Gb. Anybody who needs more than 64Mb/task - tough cookies). [...] Some of my "C"-files (specifically mm.c) are almost as much assembler as C. [...] Unlike minix, I also happen to LIKE interrupts, so interrupts are handled without trying to hide the reason behind them"
- செப்டம்பர் 1991 - 10,239 நிரல்வரிகளைக்கொண்ட லினக்ஸின் பதிப்பு 0.01 வெளியாகிறது.
- அக்டோபர் 1991 - லினக்ஸின் பதிப்பு 0.02 வெளியாகிறது.[3]
- டிசம்பர் 1991 - லினக்ஸின் பதிப்பு 0.11 வெளியாகிறது. This version is the first that is self-hosted. (that is: you can compile Linux 0.11 under Linux 0.11)
- 19 ஜனவரி 1992 - ஆல்ட்.ஓஸ்.லினக்ஸ் செய்திக்குழுவில் முதன்முறையாக பதிவேற்றப்படுகிறது. [4]
- 31 மார்ச் 1992 - கொம்ப்.ஓஎஸ்.லினக்ஸ் செய்திக்குழு தொடங்கப்படுகிறது. [5]
- மார்ச் 1992 - Linux version 0.95 is the first to be capable of running the X Window System.
- During the whole of 1993, and early 1994 - 15 development versions 0.99.*, with 0.99.11 (July 1993) introducing BogoMips into the kernel
- 14 மார்ச் 1994 - 176,250 நிரல்வரிகளைக்கொண்ட லினக்ஸின் பதிப்பு 1.0.0 வெளியாகிறது.
- மார்ச் 1995 - 310,950 நிரல்வரிகளைக்கொண்ட லினக்ஸின் பதிப்பு 1.2.0 வெளியாகிறது.
- 9 மே 1996 - டக்ஸ் பென்குயின் லினக்ஸின் சின்னமாக பரிந்துறைக்கப்படுகிறது.
- 9 ஜூன் 1996 - 777,956 நிரல்வரிகளைக்கொண்ட லினக்ஸின் பதிப்பு 2.0.0 வெளியாகிறது.
- 25 ஜனவரி 1999 - Linux 2.2.0 is released, very buggy at first. (1,800,847 lines of code.)
- 18 December 1999 - ஐபிஎம் mainframe patches for 2.2.13 published, bringing Linux into the biggest enterprises.
- 4 January 2001 - Linux 2.4.0 is released. (3,377,902 lines of code.)
- 17 December 2003 - Linux 2.6.0 is released. (5,929,913 lines of code.)
[தொகு] பாகங்கள்
Further developing his own code and integrating changes made by other programmers, Linus Torvalds keeps releasing new versions of the Linux kernel. These are called "vanilla" kernels, meaning they have not been modified by anyone. Many providers of GNU/Linux operating systems modify the kernels of their product, mainly in order to add support for drivers or features which have not officially been released as stable, while some distributions, such as Slackware, rely on vanilla kernels.
[தொகு] தொகுப்பை வரிசைப்படுத்தும் முறை
The version number of the Linux kernel currently consists of four numbers, following a recent change in the long-standing policy of a three-number versioning scheme. For illustration, let it be assumed that the version number is composed thus: A.B.C[.D] (e.g. 2.2.1, 2.4.13 or 2.6.12.3).
- The A number denotes the kernel version. It is changed least frequently, and only when major changes in the code and the concept of the kernel occur. It has been changed twice in the history of the kernel: In 1994 (version 1.0) and in 1996 (version 2.0).
- The B number denotes the major revision of the kernel. Even numbers indicate a stable release, i.e. one that is deemed fit for production use, such as 1.2, 2.4 or 2.6. Odd numbers are development releases, such as 1.1 or 2.5. They are for testing new features and drivers until they become sufficiently stable to be included in a stable release.
- The C number indicates the minor revision of the kernel. In the old three-number versioning scheme, this was changed when security patches, bugfixes, new features or drivers were implemented in the kernel. With the new policy, however, it is only changed when new drivers or features are introduced; minor fixes are handled by the D number.
- A D number first occurred when a grave error, which required immediate fixing, was encountered in 2.6.8's NFS code. However, there were not enough other changes to legitimate the release of a new minor revision (which would have been 2.6.9). So, 2.6.8.1 was released, with the only change being the fix of that error. With 2.6.11, this was adopted as the new official versioning policy. Bugfixes and security patches are now managed by the fourth number, whereas bigger changes are only implemented in minor revision changes (the C number).
[தொகு] பராமரிப்பு
லினஸ் ரோவாட்ஸ் மூல நிரல்களை மேற்பார்வை செய்து பிந்தைய கேர்னலுடன் வெளிவிடுவதும் பழைய கேர்னகளை வேறு நிரலாக்கர்களைப் பராமரிக்கவிடுகின்றார். W
| Kernel series | Maintainer |
|---|---|
| 2.0 | டேவிட் வீனிஹால் |
| 2.2 | மார்க் கிறிஸ்டியன் பீட்ஸ்ரசன்Marc-Christian Petersen (முன்னர் ஆலன் ஹாக்ஸ்) |
| 2.4 | en:Marcelo Tosatti |
| 2.6 | ஆண்டிறு மோட்டன் / லினஸ் ரோவாட்ஸ் |
மற்றும் வேறு லினஸ் கேணல் நிரலாக்கர்கள் ராபட் லவ் en:Ingo Molnar . (See the லினக்ஸை பராமரிப்பவர்களின் கோப்பு).
[தொகு] நிலைத்து நிற்கும் பாகங்களின் வரலாறு
- Version 1.0 of March 1994 supported only single-processor i386 machines.
- Version 1.2 of March 1995 added support for Alpha, Sparc and Mips.
- Version 2.0 of June 1996 added support for more processors and included SMP support.
- Version 2.2 of January 1999 (The Wonderful World of Linux 2.2).
- Version 2.4.0 of January 2001
- CPU support: Hewlett-Packard's PA-RISC processor, Axis Communications' ETRAX CRIS ("Code Reduced Instruction Set") processors
- added ISA Plug-and-Play
- added USB and PC Card support
- 2.4.6: added Bluetooth support
- Filesystem and data storage
- added Logical Volume Manager version 1 (LVM)
- support for RAID devices
- 2.4.15: Support for InterMezzo filesystem were added.
- For more information see article: Wonderful World of Linux 2.4
- Version 2.6 of December 17, 2003
- integrated uClinux (for microcontrollers)
- CPU support: with support for Hitachi's H8/300 series, the NEC v850, and Motorola's embedded m68k processors, NUMA support, support for NCR's Voyager architecture, support for Intel's hyperthreading and PAE ("Physical Address Extension")
- integrated the ALSA sound driver
- OS support:
- Improved APIC support.
- Increased the maximum number of users and groups from 65,000 to over 4 billion.
- Increased the maximum number of process ids from 32,000 to 1 billion.
- Increased the maximum number of device types (major device) from 255 to 4095 and the maximum number of devices of each type (minor device) from 255 to more than a million.
- Improved 64-bit support and filesystems of up to 16 terabytes on common hardware.
- Improvements to the "overall responsiveness" for interactive processes (the kernel became fully preemptible and the I/O scheduler was rewritten).
- Support for futexes, a rewrite of threading infrastructure to allow the Native POSIX Thread Library (NPTL) to be used.
- An improved module loader.
- User Mode Linux integration.
- 2.6.11 Infiniband support
- Storage Support:
- LVM updated to version 2
- support for SGI's XFS filesystem.
- A new "system filesystem" called sysfs, destined to relieve procfs of its system related information.
- 2.6.12 (17 June 2005) iSCSI support
- 2.6.13 inotify support
- (and more changes: The Wonderful World of Linux 2.6)
[தொகு] கட்டமைப்பு
The Linux kernel includes true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management, and TCP/IP networking.
Today Linux is a module-loading monolithic kernel. Device drivers and kernel extensions typically run in ring 0, with full access to the hardware, although some run in user space. Unlike standard monolithic kernels, device drivers are easily configured as modules, and loaded or unloaded while running the system. Also unlike standard monolithic kernels, device drivers can be pre-empted under certain conditions. This latter feature was added to handle hardware interrupts correctly, and to improve support for symmetric multiprocessing. Preemption also improves latency, increasing responsiveness and making Linux more suitable for real-time applications.
The fact that Linux is not a microkernel was the topic of a famous flame war between Linus Torvalds and Andy Tanenbaum on comp.os.minix in 1992. [7] [8]
The complete source code of various versions of the Linux kernel can be browsed at http://lxr.linux.no .
[தொகு] Programming languages
The Linux kernel is written in the version of the C programming language supported by the GNU GCC compiler (which supports a superset of standard C), together with relatively short sections of code written in the assembly language of the target architecture (and at last count Linux supported about 20 different processor families). Because of the extensions to C supported by the GCC compiler it was (in conjunction with its associated toolset) for long the only compiler capable of correctly building a Linux kernel. More recently Intel claims to have modified its C compiler so that it also is capable of compiling the kernel.
Many other languages are used in some way, primarily in connection with the kernel 'build' process (the methods whereby the bootable image is created from the sources). These include Perl, Python, and various shell scripting languages. Some drivers may also be written in C++, Fortran, or other languages, but this behaviour is strongly discouraged. The kernels build system only supports GCC as kernel and driver compiler.
[தொகு] Portability
While not originally intended as a portable operating system, Linux is now one of the most widely ported operating system kernels (although NetBSD has been ported to almost as many architectures), running on a diverse range of systems from the iPAQ (a handheld computer) to the ஐபிஎம் System z9 (a massive mainframe server that can run hundreds or even thousands of concurrent Linux instances). Linux is intended to run as the main operating system on ஐபிஎம்'s new Blue Gene supercomputer architecture when it is finished. Linus included, perhaps humorously, BogoMips into the kernel as a performance pseudo-comparison tool.
It is important to note that Linus's efforts were also directed successfully at a different sort of portability. Portability, according to Linus, was the ability to easily compile applications from a variety of sources on his system; thus Linux originally became popular in part because it required the least effort to get popular GPLed and other open source applications running.
Linux currently runs on the following machine architectures:
- ARM
- Acorn: Archimedes, A5000 and RiscPC series
- StrongARM, Intel XScale etc.
- HP's iPAQ
- Nintendo's DS (DS Linux Project)
- Apple's iPod (IPodLinux iPodLinux Project)
- Axis Communications' CRIS
- Hewlett Packard's Alpha
- Hewlett Packard's PA-RISC
- Hitachi: SuperH (SEGA Dreamcast), H8/300
- IBM's S/390 (31-bit)
- IBM's zSeries and System z9 mainframes (64-bit)
- Intel 80386 and up: ஐபிஎம் PCs and compatibles with CPUs:
- 80386, 80486, and their AMD, Cyrix, TI and ஐபிஎம் variants
- the entire Pentium series;
- AMD 5x86, K5, K6, Athlon (all 32-bit versions), Duron;
- AMD64: AMD's 64-bit processor technology (formerly known as x86-64)
- Cyrix 5x86, 6x86 (M1), 6x86MX and MediaGX (National/AMD Geode) series.
- VIA Technologies VIA C3 and later processors
- Support for Intel 8086, 8088, 80186, 80188 and 80286 CPUs is under development (see ELKS project)
- Microsoft's Xbox (Pentium III processor) (see Xbox Linux)
- Intel IA-64
- MIPS
- Silicon Graphics, Inc.
- Cobalt Qube, Cobalt Raq
- Sony PlayStation 2 (see PS2 Linux)
- DECstation
- several others
- Motorola 68020 and up:
- newer Amigas: A1200, A2500, A3000, A4000
- Apple Macintosh II, LC, Quadra, Centris and early Performa series
- Sun Microsystems 3-series workstations (experimental, uses Sun-3 MMU)
- Non-Sun 68020-based machines require the Motorola 68851 PMMU
- NEC v850e
- Renesas M32R
- PowerPC and ஐபிஎம் POWER:
- most newer Apple computers (all PCI-based Power Macintoshes, limited support for the older NuBus Power Macs)
- clones of the PCI Power Mac marketed by Power Computing, UMAX and Motorola
- Amigas upgraded with a "Power-UP" card (such as the Blizzard or CyberStorm)
- IBM RS/6000, iSeries and pSeries systems
- Pegasos I and II boards
- several embedded PowerPC platforms
- SPARC and UltraSparc: Sun 4-series, SPARCstation/SPARCserver, Ultra, Blade and Fire series workstations and servers, as well as clones made by Tatung and others.
A complete list of ports is at Linux Ports.
[தொகு] காப்புரிமை ஆவணங்கள்
முதன்முதலில், டோர்வோல்டு அவர்கள், லினக்ஸை, எந்த ஒரு வர்த்தகமும் தன் வசப்படுத்திக்கொள்ளாதவாறு அதன் காப்புரிமையை அமைத்துள்ளார். பின்னர் ஜி.என்.யு ஜன்ரல் புப்ளிக் காப்புரிமைக்கு (பாகம் 2) மாற்றப்பட்டது. இந்த ஆவணங்கள், லினக்ஸ் தொகுப்பை பரிமாறிகொள்ளவும் மற்றும் அதனை மாற்றம் செய்ததை விற்கவும் வழிசெய்கிறது. அவ்வாறு செய்யப்படும் லினக்ஸ் தொகுப்பு, அதன் சோர்ஸ் கோடையையும் சேர்த்து இதெ காப்புரிமையின் கீழ் வெளியிடப்பட வேண்டும்.
திரு. டோர்வோல்டு அவர்கள், லினக்ஸின் ஜி.பி.எல் காப்புரிமைப் பற்றி பேசும்பொழுது, "best thing I ever did." என்று வர்ணித்துள்ளார் இந்த தொடுப்பை காணவும்[9]
One general question about the application of the GPL to Linux involves whether loadable kernel modules are considered "derived works" under copyright law, and thereby fall under the terms of the GPL. Torvalds has stated his belief that modules using only a limited, "public" subset of the kernel interfaces can sometimes be non-derived works, thus allowing some binary-only drivers and other modules not obeying the GPL. Not all kernel contributors agree with this interpretation, however, and even Torvalds agrees that many kernel modules are clearly derived works, and indeed he states that kernel modules ARE derivative "by default"; ultimately, such questions can only be resolved by a court.
Linux is a registered trademark of Linus Torvalds.
[தொகு] சின்னம்
லினக்ஸின் சின்னம் டக்ஸ் (TUX) எனப் பெயரிடப்பட்ட பென்குயின் பறவையாகும். இச்சின்னத்தை உருவாக்கியவர் அமெரிக்காவை சேர்ந்த நிரலாளர் இலாரி இவிங். 'இலாரி இவிங்'கின் டக்ஸ் பக்கம்
டக்ஸின் உருவம் பல மாறுபட்ட வடிவங்களில் காணப்படுகிறது, சில தோற்றங்கள் முப்பரிமான வடிவிலும் உள்ளன. லினக்ஸின் சின்னம் ஏன் பென்குயின் பறவை என்பதற்கு லினஸ் டோர்வால்ஸின் பதில் "லினஸிற்கு பென்குயின் பிடிக்கும், அவ்வளவே".
டக்ஸ் எனப்பெயர் வர காரணம் ஆங்கிலத்தில் டோர்வால்ஸின் லினக்ஸ் (Torvalds' LinUX) என்பதின் சுருக்கமென கறுதப்படுகிறது. டக்ஸ் பெயர் காரணம்
[தொகு] Kernel panic
- Main article: Kernel panic
In Linux, a "panic" is an unrecoverable system error detected by the kernel as opposed to similar errors detected by user space code. It is possible for kernel code to indicate such a condition by calling the panic function located in the header file sys/system.h. However, most panics are the result of unhandled processor exceptions in kernel code, such as references to invalid memory addresses. These are typically indicative of a bug somewhere in the call chain leading to the panic.
[தொகு] வெளி இணைப்புகள்
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இந்தக் குறுங்கட்டுரையை விரிவாக்கி நீங்களும் இதன் வளர்ச்சியில் பங்களிக்கலாம். |
