abclinuxu.cz AbcLinuxu.cz itbiz.cz ITBiz.cz HDmag.cz HDmag.cz abcprace.cz AbcPráce.cz
AbcLinuxu hledá autory!
Inzerujte na AbcPráce.cz od 950 Kč
Rozšířené hledání
×
    dnes 21:00 | Komunita

    Rakouská armáda přechází na LibreOffice. Ne kvůli licencím (16 000 počítačů). Hlavním důvodem je digitální suverenita. Prezentace v pdf z LibreOffice Conference 2025.

    Ladislav Hagara | Komentářů: 0
    dnes 12:44 | Bezpečnostní upozornění

    Národní úřad pro kybernetickou a informační bezpečnost (NÚKIB) upozorňuje na sérii kritických zranitelností v Cisco Adaptive Security Appliance (ASA) a Firepower Threat Defense (FTD) a Cisco IOS, CVE-2025-20333, CVE-2025-20363 a CVE-2025-20362. Zneužití těchto zranitelností může umožnit vzdálenému neautentizovanému útočníkovi spustit libovolný kód (RCE). Společnost Cisco uvedla, že si je vědoma aktivního zneužívání těchto zranitelností.

    Ladislav Hagara | Komentářů: 7
    dnes 12:11 | IT novinky

    Ochrana uživatelů a zároveň příznivé podmínky pro rozvoj umělé inteligence (AI). Ministerstvo průmyslu a obchodu (MPO) připravilo minimalistický návrh implementace evropského nařízení o umělé inteligenci, tzv. AI aktu. Český zákon zajišťuje ochranu občanům a bezpečné používání AI, ale zároveň vytváří pro-inovační prostředí, ve kterém se může AI naplno rozvíjet, firmy mohou využít jeho potenciál a nebudou zatíženy zbytečnou administrativou. Návrh je nyní v meziresortním připomínkovém řízení.

    Ladislav Hagara | Komentářů: 6
    dnes 05:11 | Komunita

    Dle plánu Linus Torvalds odstranil souborový systém bcachefs z mainline Linuxu. Tvůrce bcachefs Kent Overstreet na Patreonu informuje, že bcachefs je nově distribuován jako DKMS modul.

    Ladislav Hagara | Komentářů: 2
    včera 17:44 | IT novinky

    PIF, Silver Lake a Affinity Partners kupují videoherní společnost Electronic Arts (EA) za 55 miliard dolarů (1,14 bilionu korun).

    Ladislav Hagara | Komentářů: 2
    včera 16:33 | Pozvánky

    Konference LinuxDays 2025 proběhne již tento víkend 4. a 5. října v Praze v areálu ČVUT v Dejvicích na FIT. Konference znamená desítky přednášek a workshopů, zástup zajímavých osobností, místo pro setkání, spoustu nových nápadů a informací a stánky řady různých projektů: Fedora, openSUSE, vpsFree.cz, Mozilla, MacGyver - bastlíři SH, OpenAlt a mnoho dalších. Účast na konferenci je zdarma.

    Ladislav Hagara | Komentářů: 0
    včera 14:22 | Zajímavý článek

    Před měsícem Google oznámil, že bude vyžadovat ověření identity vývojářů aplikací pro Android. Dnes se k této změně vyjádřil F-Droid, tj. instalovatelný katalog svobodných a open source aplikací pro platformu Android. Změna ohrožuje F-Droid a další otevřené platformy pro distribuci aplikací.

    Ladislav Hagara | Komentářů: 15
    včera 00:22 | Nová verze

    Po 9 týdnech vývoje od vydání Linuxu 6.16 oznámil Linus Torvalds vydání Linuxu 6.17. Přehled novinek a vylepšení na LWN.net: první a druhá polovina začleňovacího okna a Linux Kernel Newbies.

    Ladislav Hagara | Komentářů: 0
    včera 00:11 | Pozvánky

    The Catch 2025, oblíbená podzimní CTF (Capture the Flag) soutěž, začne v pondělí 6. října přesně ve 12:00. Letošní ročník s podtitulem TCC Power Grid prověří znalosti hráček a hráčů na scénářích spojených s elektrickou rozvodnou sítí. Kromě hlavních výher čekají na soutěžící ceny až do 50. místa a také speciální bonusy za nejrychlejší řešení či kvalitní write-upy.

    Ladislav Hagara | Komentářů: 0
    26.9. 17:22 | Nová verze

    Společnost System76 vydala beta verzi Pop!_OS 24.04 LTS s novým desktopovým prostředím COSMIC. Videoukázky na YouTube.

    Ladislav Hagara | Komentářů: 6
    Jaké řešení používáte k vývoji / práci?
     (39%)
     (49%)
     (12%)
     (14%)
     (16%)
     (14%)
     (19%)
     (14%)
     (14%)
    Celkem 140 hlasů
     Komentářů: 9, poslední 24.9. 17:28
    Rozcestník

    AToL: Packages for embedded devices

    23.3.2009 07:07 | Přečteno: 945× | Linux | Výběrový blog | poslední úprava: 20.3.2009 21:10

    Author: Jaromír Dobiáš
    Packages are nowadays the most usual way of installation of a new software in Unix-like operating systems. I would like to mention general properties of packages used by package management systems in this article. I would like to focus on description of basic properties of Ipk packages which are dedicated for embedded devices based on GNU/Linux.

    1. Packages and package management systems

    Packages might be nothing new for the most of you. They have become an ordinary part of modern Unix-like environments and many people get used to them as the most used way for the software installation. However not all of those people might be aware of what are the biggest pros of packages. Let us therefore have a look at what are the most essential advantages of packages in comparison with conventional ways of software installation in Unix-like operating systems.

    1.1 What is the package ?

    Term "package" denotes a simple file or set of several files which can be used for installation of a new software in Unix-like operating systems. There are two basic types of packages. First type, which is most widely spread today, uses structure where all the data, precompiled from the source codes, are included directly in the simple package file. Second type of packages, which is typical for Gentoo GNU/Linux distribution, uses another approach where package itself is used for coordination of download and compilation of source codes and subsequent deployment in the targeted system.

    1.2 Advantages of packages

    Data is recorder to desired locations of the file-structure of the targeted system during installation of a package. Package management systems store information about location of each particular file which is deployed to the system. Hence it is possible to easily seek out what files have been recorded and where, when installing a particular package. On the other hand this is not the case of conventional installation (e.g. using ./configure, make and make install). The system can be more transparent and better organized when packages are used as a resource of a data.

    Another advantage of packages is that they usually consist of precompiled data, which has been compiled on a single machine prior to its' distribution. Installation of such packages is therefore much faster because we don't need to compile it separately in each targeted system.

    Some packages can be rapidly smaller than the original source files which they were built from. This should be taken into consideration especially when Internet is the primary source for distribution of packages. In such a case packages can help us to save more time and bandwidth.

    Package management systems take advantage of storing several packages in particular locations called "repositories". In advanced package management systems it is sufficient to set up one or possibly more URLs of desired repositories, where to take the packages from. The system is then able to synchronize the list of available packages with those repositories. The advantage is, that it's faster to find a specific package using repository than it is using ordinary search engines.

    More advanced package management systems are capable of solving dependency issues. Those systems can provide automation of download and installation of additional packages which our packages relay on (typically libraries).

    1.3 Pros and cons of packages

    From the previous follows, that the main advantage of packages lies in reduction of time needed for installation of desired data. Packages allow us to have actualized programs, data and the system itself in a shorter time and with less effort when compared to native ways of installation.

    On the other hand some problems might arise when using packages. Typical problem might occur when the application installed from package is not equipped with desired functionality as a result of not being compiled with certain parameter or switch (e.g. SSH daemon without pluggable authentication modules support). For such situation there usually exist tools which enables you to build your own package from the source codes. In some more specific cases it might be more desirable to install the application in an ordinary way without the help of packaging.

    2. Ipk package format

    Ipk is package format for Itsy Package Management System (IPKG). It is very lightweight format designated for embedded devices operating with Unix-like operating system. Ipk packages are used e.g. in smartphone devices working with Openmoko OS (GNU/Linux for mobile phones). We can use Ipk packages in some Linux-based WiFi routers as well (e.g. equipped with OpenWrt distribution).

    2.1 Structure of the Ipk package format

    Ipkg package is in fact just a simple tar or tar-gzip compressed file. When it is decompressed we can get 3 files of the package:

    1. ./control.tar.gz
      This file is compressed archive as well. It contains the main data (e.g. application, library, game etc.) which the package was made from. Data files from this archive are extracted and deployed to the targeted system during the installation of the package. Files are stored in prepared directory locations according to the final location in the targeted system.
    2. ./data.tar.gz
      This file is compressed archive as well. It contains the main data (e.g. application, library, game etc.) which the package was made from. Data files from this archive are extracted and deployed to the targeted system during the installation of the package. Files are stored in prepared directory locations according to the final location in the targeted system.
    3. ./debian-binary
      Last file included in the Ipk package archive is a simple text file which tells the version of a binary package. In the time of writing this article, the only content of this file is a string "2.0". This file is actually ignored by the Ipk package management system and has no impact on the package.

    2.2 How to get the Ipk packages

    There is a search engine dedicated for searching the Ipk packages available at http://ipkgfind.handhelds.org/. Generally holds that each embedded device architecture has its' own repository of packages created for that specific platform.

    t is also possible to create packages on your own using the Ipkg-utils tool or by using the script ipkg-build.sh. In order to create your own package it is necessary to make the directory structure and fill it with the files according to the desired structure in the targeted system. When creating the package the structure of directories should be created in some particular directory which represents the root of the file-system tree of the targeted system. It is necessary to create subdirectory called CONTROL in this root representative and subdirectory CONTROL should contain a file called control in it. As mentioned before, control is a meta-data file which has several attributes describing the package. Each attribute is on a single line and their names and meanings are the following:

    Additional attributes are optional in the file control and does not have to exist there by default:

    3. Summary

    Packages and package management systems are fast and effective way for installation and upgrade of data in Unix-like environment. In this article, I tried to point out the main advantages of packages and I tried to emphasize their role in Linux-based systems of embedded devices. When talking about embedded devices it is necessary to keep in mind their memory and performance limitations above all. Therefore functionality of the software installed to such devices must be reduced.

    4. Resources

           

    Hodnocení: 56 %

            špatnédobré        

    Anketa

    How do you rate this article?
     (0 %)
     (82 %)
     (18 %)
    Celkem 17 hlasů

    Tiskni Sdílej: Linkuj Jaggni to Vybrali.sme.sk Google Del.icio.us Facebook

    Komentáře

    Vložit další komentář

    Grunt avatar 23.3.2009 20:53 Grunt | skóre: 23 | blog: Expresivní zabručení | Lanžhot
    Rozbalit Rozbalit vše Re: AToL: Packages for embedded devices

    Zrovna se chystám kompilovat nějaké balíčky pro OpenWRT, takže díky za článek.

    BTW: Hodilo by se to i do Wikiny jakožto nějaký úvod.

    Na co 64-bitů když to jde i s jedním? | 80.78.148.5 | Hack (for) free or Die Hard!
    =^..^= AmigaPower® avatar 24.3.2009 15:33 =^..^= AmigaPower® | skóre: 30 | blog: BLB | Praha
    Rozbalit Rozbalit vše Re: AToL: Packages for embedded devices
    Začnu psát zápisky korejsky...
    ISSN 1214-1267   www.czech-server.cz
    © 1999-2015 Nitemedia s. r. o. Všechna práva vyhrazena.