Difference between revisions of "Boot process"

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= the init script are executed =
 
= the init script are executed =
This can be SysV init scripts or upstart or systemd. One of them is dbus.
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This can be SysV init scripts or upstart or systemd. These init scripts typically start services. Services are grouped into runlevels. Some notable services are:
 +
* alsasound
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: Used for the alsa sound system
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* cups
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: Used for printing, it is the common Unix printing system
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* dbus
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: Used to call public functions in running programs. Should be abstracted to users.
 +
* esound
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: Used for enlightenment sound system
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* ntp
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* autofs          boot.udev                xdm
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* cifs              xfs
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* cron                        ypbind
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* powerd     
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*      gpm          network    sshd
  
 
= X Windowing system is started =
 
= X Windowing system is started =

Revision as of 14:45, 11 January 2014

How Linux typically starts up on a PC

you switch on the computer

BIOS is shown and the devices are check

the master boot record is executed

the boot loader is executed

The boot loader is typically grub, and there is an older and smaller called lilo.

the Linux kernel is executed

the initrd is loaded/executed

the init program is started

The Linux kernel starts the init program. Nothing else. If the init process quits, the Linux kernel panics. Init is responsible for all further services and programs that are started.

the init script are executed

This can be SysV init scripts or upstart or systemd. These init scripts typically start services. Services are grouped into runlevels. Some notable services are:

  • alsasound
Used for the alsa sound system
  • cups
Used for printing, it is the common Unix printing system
  • dbus
Used to call public functions in running programs. Should be abstracted to users.
  • esound
Used for enlightenment sound system
  • ntp
  • autofs boot.udev xdm
  • cifs xfs
  • cron ypbind
  • powerd
  • gpm network sshd

X Windowing system is started

login manager is started

user session incl. Desktop environment is started

See also