7. Glossary

• Cluster : Grape(s) of heterogeneous machines which runs enslaved beneath a Master machine,a server, centralizing memory, access requests, etc.. Use in grid computation or in massive calculsus.
• Flash : Action aiming to write data into a chip such as EPROM or EEPROM (Electronic (Erasable) Programmable Read Only Memory). In this project all of them are EEPROM.

• BIOS : BIOS stands for Basic Input/Output System. Kind of minisystem before the Operating System (OS).

• CMOS : EEPROM/EPROM Chip that stores the BIOS binary code.

• Cross Compiling : Useful notably when resources are low on a machine (constraint milieu, embedded device) this technic enables another machine to 'tune' its parameters (such as memory quantity, cpu type and so on) to the former and to emulate its behavior. As a result and because the later have higher capacities, compiling goes faster and so does tests and validation.
• Shadow RAM : Part of the RAM memory reserved by the BIOS to copy itself as a shadow mainly in order to be run and accessed more quickly.
• CHS geometry : Cynlinders/Heads/Sectors 3D mapping of a harddisk. The reason why it is still used is now historical.Now Abstracted by LBA (Logical/Large Block Access) enabling more than 528Mb disks mapping.
• RAM : (Random Access Memory) Essential memory that stores info for a session. Dumped upon reset button-push (reboot) nowadays RAM's content is partly auto-sustaintive (not dumped by simple reset)
• ACPI : Advanced Configuration of Power Managment Interface. Enables the BIOS to shut down a device after a certain period. Also let the OS user monitors and tweaks theses settings.
• Table descriptors : GDT stands for Global Descriptor Table, LDT stands for Local Descriptor Table, IDT for Interrupt Descriptor Table.
• DMA Channels : Direct Memory Assignment. Programmed Input/Output (PIO) is a serious concurrent to this mode.
• IRQ : Interrupt ReQuests Handlers triggers an normal code branch interruption. A bit deprecated since PnP norm.
• Assembly code : Alpha,Aleph code, the first generation code.
• C code : second generation code (B code has never existed)
• MBR/PBR : Master Boot Record, Partition Boot Record holds 512 bytes (a standard sector).
• MTRR : Memory Type Range Register, grosso modo theses are registers reserved to initialize dialog between PCI and AGP regarding to the video card. Their correct intialization boots performance notably.
• Failsafe, Fallback : Failsafe is a stable emergency mode which enables you to repair the system to work back in normal mode. Fallback is Linuxbios stable emergency BIOS image stored in a ROM which is loaded on main BIOS image error.
• Kernel Panic, Fatal Error : Major system error, unavoidable, uncurable, often unpredictable. In short a disappointment.
• Boot Process : System Initialization sequence is standard IEEE 1275-1994.
• Boot Loader : Code residing in MBR block that reads the 55AAH signature and loads OS.
• LILO : LInux LOader.
• GRUB : GRand Unified Bootloader.
• VFS : Virtual FileSystem. Abstracted device driver layer for file systems.
• POST : Power On Self Test is mostly a boot sequence designation standard integrated in PCI card hardware or in some motherboard itself. It gives a good review but prefer Linuxbios debug string transit via serial cable.
• RamDisk : Coming with RAMFS, this is a standard file systems that resides in RAM memory instead of disk memory. It is a close friend of TMPFS (TeMPorary FileSystem).
• Deamon : "background" running program. Listenning to client connection and registration to a given service. It relays service offer and request to client connection.
• VGA : Video Graphic Array. SVGA stands for Super VGA.