When you turn on BcalcOS, several components work together to take the computer from power-on to the desktop.
BIOS / UEFI
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Bootloader
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Linux kernel
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SysVinit
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SLiM
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XLibre
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Xfce desktop
BIOS / UEFI
The computer’s firmware starts first. It initializes the hardware and looks for a bootable operating system. BcalcOS supports both traditional BIOS and UEFI systems.
Bootloader
The bootloader starts the operating system. BcalcOS uses GRUB, which locates the Linux kernel and starts it.
Linux kernel
The Linux kernel takes control of the computer’s hardware and system resources. It then starts the first user-space process.
SysVinit
BcalcOS uses SysVinit as its system initialization system. SysVinit starts the services and processes needed for the operating system to run.
SLiM
SLiM is the display manager. It provides the graphical login screen.
XLibre
XLibre is the display server. It provides the graphical foundation that allows applications and the desktop environment to display windows, menus, and other graphical elements.
Xfce
Xfce is the desktop environment. It provides the desktop, panels, menus, windows, file manager, and other parts of the graphical user interface.