.bss

:"bss" redirects here. For other uses, see BSS."

In computer programming, .bss or bss (Block Started by Symbol) is used by many compilers and linkers as the name of the data segment containing static variables that are filled solely with zero-valued data initially (i. e., when execution begins). It is often referred to as the "bss section" or "bss segment". The program loader initializes the memory allocated for the bss section when it loads the program.

In an object module compiled from C, the bss section contains the local variables (but not functions) that were declared with the static keyword, except for those with non-zero initial values. (In C, static variables are initialized to zero by default.) It also contains the non-local (both extern and static) variables that are also initialized to zero (either explicitly or by default).

Historically, BSS (from Block Started by Symbol) was a pseudo-operation in UA-SAP (United Aircraft Symbolic Assembly Program), the assembler developed in the mid-1950s for the IBM 704 by Roy Nutt, Walter Ramshaw, and others at United Aircraft Corporation.

The BSS keyword was later incorporated into FAP (FORTRAN Assembly Program), IBM's standard assembler for its 709 and 7090/94 computers. It defined a label and reserved uninitialized space for a given number of words.

In embedded software, the BSS segment is mapped into "Uninitialized RAM" that in fact is initialized to zero by the C runtime before main () is entered. Additionally, some compilers/architectures support the SBSS segment for "small data". Typically these data items can be accessed by leaner code using instructions that can only access a certain range of addresses.

See also

* Linker
* Data segment
* Code segment
* Uninitialized variable

External links

* " [http://www.faqs.org/faqs/unix-faq/faq/part1/section-3.html Unix FAQ section 1.3] ", where Dennis Ritchie explains the origins of the term "bss"


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • BSS 01 — (Bildschirmspiel 01) Hersteller …   Deutsch Wikipedia

  • Bss — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. {{{image}}}   Sigles d une seule lettre   Sigles de deux lettres > Sigles de trois lettres …   Wikipédia en Français

  • BSS — is a three letter abbreviation that may refer to:Institutions * Bayridge Secondary School, Canada * Bayview Secondary School, Canada * Bishop Strachan School, Canada * Bramalea Secondary School, Canada * Blessed Sacrement School, Walpole,… …   Wikipedia

  • Bss — Die Abkürzung BSS steht für: Broadcasting Satellite Services (Rundfunkdienste via Satellit) Base Station Subsystem (Mobilfunk) Basic Service Set (bei WLANs) Als Blind Source Separation bezeichnet man das Problem, die zugrundeliegenden Quellen… …   Deutsch Wikipedia

  • BSS — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom.   Sigles d’une seule lettre   Sigles de deux lettres > Sigles de trois lettres   Sigles de quatre lettres …   Wikipédia en Français

  • BSS — Die Abkürzung BSS steht für: Base Station Subsystem, der funkbezogene Teil eines GSM Netzes im Mobilfunk Bad Soden Salmünster, eine hessische Stadt im Main Kinzig Kreis Bernard Soulier Syndrom, ein Krankheitsbild in der Hämatologie Basic Service… …   Deutsch Wikipedia

  • BSS — У этого термина существуют и другие значения, см. BSS (значения). Подсистема базовых станций (сокр. ПБС, англ. base station subsystem, BSS)  один из основных элементов системы подвижной радиотелефонной связи, ответственный за передачу… …   Википедия

  • BSS — Best Shot Selector (Computing » Software) Basic Service Set (Computing » Networking) Basic Service Set (Computing » Telecom) **** Base Station System (Academic & Science » Amateur Radio) **** Business Support Systems (Business » General) *… …   Abbreviations dictionary

  • BSS — Bachelor of Sanitary Science; balanced salt solution; Bernard Soulier syndrome; black silk suture; buffered salt solution; buffered single substrate * * * see balanced salt solution * * * Bernard Soulier syndrome …   Medical dictionary

  • BSS — • Basic Synchronised Subset (in Bezug auf Datenkommunikation auf ISO /OSI Schicht 5) enthält Grundfunktionen der Kommunikation und Synchronisationsdienste • Block Started by Symbol (IBM) • Basic Stack Segment • Base Station Subsystem, die Summe… …   Acronyms

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.