{"id":57,"date":"2013-04-30T01:21:21","date_gmt":"2013-04-29T22:21:21","guid":{"rendered":"http:\/\/www.mustafaozcan.info\/blog\/?p=57"},"modified":"2015-04-09T10:56:13","modified_gmt":"2015-04-09T07:56:13","slug":"endian-ve-big-endian-nedir","status":"publish","type":"post","link":"http:\/\/www.mustafaozcan.info\/blog\/endian-ve-big-endian-nedir.html","title":{"rendered":"Little Endian ve Big Endian Nedir ?"},"content":{"rendered":"
<\/div><\/div>

Little Endian ve Big Endian kavramlar\u0131n\u0131 \u00f6\u011frenelim.<\/p>\n

Alfabelerde oldu\u011fu gibi sa\u011fdan sola ya da soldan sa\u011fa do\u011fru yaz\u0131m \u015feklini i\u015flemciler de byte’lar\u0131 saklarken \u00f6nemli byte’\u0131n solda veya sa\u011fda olmas\u0131na g\u00f6re s\u0131n\u0131fland\u0131r\u0131l\u0131r. Buna\u00a0endianness<\/i><\/strong>\u00a0da denir.<\/p>\n

\u0130\u015flemcilerin byte\u2019lar\u0131 saklarken kulland\u0131\u011f\u0131 s\u0131ralamad\u0131r. B\u00fcy\u00fck Sonlu (Big-Endian) ve K\u00fc\u00e7\u00fck Sonlu (Little-Endian) olmak \u00fczere ikiye ayr\u0131l\u0131r.<\/p>\n

 <\/p>\n

Little-Endian (K\u00fc\u00e7\u00fck Sonlu)<\/strong><\/p>\n

i386 ve devam\u0131 olan\u00a0i\u015flemciler Little-Endian kullan\u0131r.<\/p>\n

Elimizde 0x34E2561A 4 Byte\u2019l\u0131k Integer verimiz olsun. Sa\u011fdan itibaren ba\u015flanarak\u00a00x1A 0x56 0xE2 0x34 olarak saklan\u0131r.<\/p>\n

 <\/p>\n

Big-Endian (B\u00fcy\u00fck Sonlu)<\/strong><\/p>\n

Sun Sparc, Motorola 68K, PowerPC ve Java Sanal \u0130\u015flemcisi (Java VM) Big-Endian kullan\u0131r.<\/p>\n

0x7654139A verisi soldan itibaren ba\u015flanarak 0x76 0x54 0x13 0x9A olarak saklan\u0131r.<\/p>\n

Arap rakamlar\u0131nda oldu\u011fu gibi (\u0130ngilizce veya T\u00fcrk\u00e7ede kulland\u0131\u011f\u0131m\u0131z rakamlar) \u00f6nemli byte’\u0131n solda oldu\u011fu s\u0131ralamaya\u00a0Big-endian<\/b>\u00a0denir. \u00d6nemli byte’\u0131n en sa\u011fda oldu\u011fu s\u0131ralama ise\u00a0Little-endian\u00a0<\/b>olarak adland\u0131r\u0131l\u0131r.<\/p>\n

Microsoft ise bu olay\u0131 \u015f\u00f6yle a\u00e7\u0131klam\u0131\u015f:\u00a0Bilgisayarlar tasarlarken, bellek depolama i\u015fleme i\u00e7in iki farkl\u0131 mimariyi vard\u0131r.\u00a0<\/span>Bunlar, Big Endian ve Little Endian olarak adland\u0131r\u0131l\u0131r ve bayt bellekte sakland\u0131\u011f\u0131 s\u0131rada bak\u0131n.\u00a0<\/span>Windows NT Little Endian mimarisi tasarlanm\u0131\u015ft\u0131r ve programlar\u0131n\u0131n \u00e7o\u011fu ile baz\u0131 ba\u011f\u0131ml\u0131l\u0131k \u00fczerinde Little Endian yaz\u0131ld\u0131\u011f\u0131 Big Endian ile uyumlu olacak \u015fekilde tasarlanmam\u0131\u015ft\u0131r.<\/span><\/p>\n

\u00d6rnek 1
\nstruct
\n{
\nWORD y;
\nWORD x;
\n} POS;<\/code><\/p>\n

lparam = (DWORD) POS;<\/p>\n

Temel olarak, Little Endian kullan\u0131ld\u0131\u011f\u0131n\u0131 kodda varsay\u0131m\u0131 vard\u0131r. Ge\u00e7i\u015f bayt ‘C’ yap\u0131s\u0131nda varsay\u0131l\u0131r. Intel mimarisinde daha h\u0131zl\u0131d\u0131r, ancak Big Endian ile \u00e7al\u0131\u015fmaz.<\/p>\n

B\u00fct\u00fcn i\u015flemciler kendi s\u0131ralamas\u0131n\u0131 se\u00e7mi\u015ftir. i386 ve klonu olan i\u015flemciler Little endian’d\u0131r.\u00a0Sun Sparc,\u00a0Motorola\u00a068K ve\u00a0PowerPC\u00a0big endian<\/strong> kullan\u0131r.\u00a0Java\u00a0Sanal \u0130\u015flemcisi (Java VM) de big endian kullan\u0131r.<\/p>\n

Farkl\u0131 iki i\u015flemcisi olan makineler birbirileri ile haberle\u015fecekleri zaman (IPC), bu veri d\u00f6n\u00fc\u015f\u00fcm\u00fcn\u00fc yapmazlar ise haberle\u015femezler.<\/p>\n

A\u011f protokolleri de kendi s\u0131ralamas\u0131n\u0131 se\u00e7melidir. Aksi takdirde iki farkl\u0131 mimarideki bilgisayar IPC yaparak birbirileri ile haberle\u015fecekleri zaman anla\u015famayacaklard\u0131r. TCP\/IP big endian s\u0131ralamas\u0131n\u0131 kullan\u0131r. Bunun anlam\u0131 \u015fu: Herhangi bir paket (IP adresi, paket uzunlu\u011fu, kontrol de\u011feri gibi) g\u00f6nderilece\u011fi zaman en \u00f6nemli byte’\u0131 \u00f6nce g\u00f6nderilir ve al\u0131n\u0131r.<\/p>\n

Ortak dosya formatlar\u0131 ve endian s\u0131ras\u0131<\/span><\/em><\/p>\n