text:
BIOS
From Wikipedia, the free encyclopedia
Jump to: navigation, search
This article is about the BIOS as found in IBM PC compatibles. For other uses, see Bios (disambiguation).
For IBM PC compatible computers, BIOS (/ˈbaɪɒs/ BY-oss; an acronym for Basic Input/Output System and also known as the System BIOS, ROM BIOS or PC BIOS) is non-volatile firmware used to perform hardware initialization during the booting process (power-on startup), and to provide runtime services for operating systems and programs.[1] The BIOS firmware comes pre-installed on a personal computer's system board, and it is the first software run when powered on. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975.[2][3] Originally proprietary to the IBM PC, the BIOS has been reverse engineered by companies looking to create compatible systems. The interface of that original system serves as a de facto standard.
The BIOS in modern PCs initializes and tests the system hardware components, and loads a boot loader or an operating system from a mass memory device. In the era of MS-DOS, the BIOS provided a hardware abstraction layer for the keyboard, display, and other input/output (I/O) devices that standardized an interface to application programs and the operating system. More recent operating systems do not use the BIOS after loading, instead accessing the hardware components directly.
Most BIOS implementations are specifically designed to work with a particular computer or motherboard model, by interfacing with various devices that make up the complementary system chipset. Originally, BIOS firmware was stored in a ROM chip on the PC motherboard. In modern computer systems, the BIOS contents are stored on flash memory so it can be rewritten without removing the chip from the motherboard. This allows easy, end-user updates to the BIOS firmware so new features can be added or bugs can be fixed, but it also creates a possibility for the computer to become infected with BIOS rootkits. Furthermore, a BIOS upgrade that fails can brick the motherboard permanently, unless the system includes some form of backup for this case.
Unified Extensible Firmware Interface (UEFI) is the successor to BIOS, aiming to address its technical shortcomings.[4]
Contents
[hide]
1 History
2 User interface
3 Operation
3.1 System startup
3.2 Boot process
3.2.1 Boot priority
3.2.2 Boot failure
3.3 Boot environment
4 Extensions (option ROMs)
4.1 Boot procedure
4.2 Initialization
4.3 Physical placement
5 Operating system services
5.1 Processor microcode updates
5.2 Identification
5.3 Overclocking
5.4 Modern use
6 Configuration
6.1 Setup utility
6.2 Reprogramming
7 Hardware
8 Vendors and products
9 Security
10 Alternatives and successors
11 See also
12 Notes
13 References
14 Further reading
15 External links
History[edit]
“
/* C P / M   B A S I C   I / O    S Y S T E M    (B I O S)
                    COPYRIGHT (C) GARY A. KILDALL
                             JUNE, 1975 */
[…]
/*  B A S I C   D I S K    O P E R A T I N G   S Y S T E M  (B D O S)
                    COPYRIGHT (C) GARY A. KILDALL
                            JUNE, 1975 */
”
— An excerpt from the BDOS.PLM file header in the PL/M source code of CP/M 1.1 or CP/M 1.2 for Lawrence Livermore Laboratories (LLL)[2]
The term BIOS (Basic Input/Output System) was created by Gary Kildall[5] and first appeared in the CP/M operating system in 1975,[2][3][6][7][8] describing the machine-specific part of CP/M loaded during boot time that interfaces directly with the hardware.[3] (A CP/M machine usually has only a simple boot loader in its ROM.)
Versions of MS-DOS, PC DOS or DR-DOS contain a file called variously "IO.SYS", "IBMBIO.COM", "IBMBIO.SYS", or "DRBIOS.SYS"; this file is known as the "DOS BIOS" (also known as "DOS I/O System") and contains the lower-level hardware-specific part of the operating system. Together with the underlying hardware-specific, but operating system-independent "System BIOS", which resides in ROM, it represents the analogue to the "CP/M BIOS".
With the introduction of PS/2 machines, IBM divided the System BIOS into real-mode and protected mode portions. The real-mode portion was meant to provide backward-compatibility with existing operating systems such as DOS, and therefore was named "CBIOS" (for Compatibility BIOS), whereas the "ABIOS" (for Advanced BIOS) provided new interfaces specifically suited for multitasking operating systems such as OS/2.
User interface[edit]
“
The first commercial licensing of CP/M took place in 1975 with contracts between Digital Systems and Omron of America for use in their intelligent terminal, and with Lawrence Livermore Laboratories where CP/M was used to monitor programs in the Octopus network. Little attention was paid to CP/M for about a year. In my spare time, I worked to improve overall facilities ... By this time, CP/M had been adapted for four different controllers. ... In 1976, Glenn Ewing approached me with a problem: Imsai, Incorporated, for whom Glenn consulted, had shipped a large number of disk subsystems with a promise that an operating system would follow. I was somewhat reluctant to adapt CP/M to yet another controller, and thus the notion of a separated Basic I/O System (BIOS) evolved. In principle, the hardware dependent portions of CP/M were concentrated in the BIOS, thus allowing Glenn, or anyone else, to adapt CP/M to the Imsai equipment. Imsai was subsequently licensed to distribute CP/M version 1.3 which eventually evolved into an operating system called IMDOS.
”
— Gary Kildall[3]
The BIOS of the original IBM PC XT had no interactive user interface. Error codes or messages were displayed on the screen, or coded series of sounds were generated to signal errors when the power-on self-test (POST) had not proceeded to the point of successfully initializing a video display adapter. Options on the IBM PC and XT were set by switches and jumpers on the main board and on peripheral cards. Starting around the mid-1990s, it became typical for the BIOS ROM to include a "BIOS configuration utility" (BCU[9]) or "BIOS setup utility", accessed at system power-up by a particular key sequence. This program allowed the user to set system configuration options, of the type formerly set using DIP switches, through an interactive menu system controlled through the keyboard. In the interim period, IBM-compatible PCs—including the IBM AT—held configuration settings in battery-backed RAM and used a bootable configuration program on disk, not in the ROM, to set the configuration options contained in this memory. The disk was supplied with the computer, and if it was lost the system settings could not be changed. The same applied in general to computers with an EISA bus, for which the configuration program was called an EISA Configuration Utility (ECU).
A modern Wintel-compatible computer provides a setup routine essentially unchanged in nature from the ROM-resident BIOS setup utilities of the late 1990s; the user can configure hardware options using the keyboard and video display. Also, when errors occur at boot time, a modern BIOS usually displays user-friendly error messages, often presented as pop-up boxes in a TUI style, and offers to enter the BIOS setup utility or to ignore the error and proceed if possible. Instead of battery-backed RAM, the modern Wintel machine may store the BIOS configuration settings in flash ROM, perhaps the same flash ROM that holds the BIOS itself.
Operation[edit]
“
When we failed to produce an operating system in a timely manner, Glenn started talking with Gary about CPM ... It took several months of twisting Gary's arm to get Gary to port it to the 8080. The final success came when Glenn talked Gary into just separating the I/O from the rest of it, with Glenn promising to re-write the I/O module for the IMSAI 8080 (which he did). So CPM on the IMSAI was a joint effort between Glenn and Gary.
”
— Joe Killian[7]
System startup[edit]
“
Glenn ... would be talking with Gary, and he started twisting Gary's arm. He said, "Hey Gary, why can't we run this in this IMSAI?" "The I/O's all different, won't run." But Glenn persists and finally makes a deal with Gary. He says, "Okay Gary, if you split out the I/O, I'll write the BIOS, basic I/O's system," and Glenn named it then. "We'll split it out separately. I'll write that part, as long as you can make a division in the program there." And he got Gary to do that and Glenn put those two pieces together and was running Gary's CP/M on an IMSAI. Glenn let us know that, and it wasn't too much later than Bill was down there making arrangements with Gary Kildall to license CP/M. ... Now that the BIOS is separated out, anybody could write a BIOS for their machine, if it was 8080-based, and run this, so he started selling that separately under the company Digital Research that he formed and did quite well."
”
— Joe Killian[8]
Early Intel processors started at physical address 000FFFF0h. When a modern x86 microprocessor is reset, it starts in pseudo 16-bit real mode, initializing most registers to zero. The code segment register is initialized with selector F000h, base FFFF0000h, and limit FFFFh, so that execution starts at 4 GB minus 16 bytes (FFFFFFF0h).[10] The platform logic maps this address into the system ROM, mirroring address 000FFFF0h.
If the system has just been powered up or the reset button was pressed ("cold boot"), the full power-on self-test (POST) is run. If Ctrl+Alt+Delete was pressed ("warm boot"), a special flag value is stored in nonvolatile BIOS memory ("CMOS") before the processor is reset, and after the reset the BIOS startup code detects this flag and does not run the POST. This saves the time otherwise used to detect and test all memory.
The POST checks, identifies, and initializes system devices such as the CPU, RAM, interrupt and DMA controllers and other parts of the chipset, video display card, keyboard, hard disk drive, optical disc drive and other basic hardware.
Early IBM PCs had a little-known routine in the POST that would attempt to download a maintenance program into RAM through the keyboard port before performing any other elements of the boot process, such as before scanning for option ROMs or executing a boot loader. (No serial or parallel ports were standard on early IBM PCs, but a keyboard port of either the XT or AT / PS/2 type has been standard on practically every PC and clone.) If the download was apparently successful, the BIOS would verify a checksum on it and then run it.[11][12] This feature was intended for factory test or diagnostic purposes; while it was of limited utility outside of factory or repair facilities, it could be used in a proprietary way to boot the PC as a satellite system to a host machine (as it was used in the manufacturing environment[citation needed]).
Boot process[edit]
After the option ROM scan is completed and all detected ROM modules with valid checksums have been called, or immediately after POST in a BIOS version that does not scan for option ROMs, the BIOS calls INT 19h to start boot processing. Post-boot, programs loaded can also call INT 19h to reboot the system, but they must be careful to disable interrupts and other asynchronous hardware processes that may interfere with the BIOS rebooting process, or else the system may hang or crash while it is rebooting.
When INT 19h is called, the BIOS attempts to locate boot loader software held on a storage device designated as a "boot device", such as a hard disk, a floppy disk, CD, or DVD. It loads and executes the first boot software it finds, giving it control of the PC.[13] This is the process that is known as booting (sometimes informally called "booting up"), which is short for "bootstrapping".
The BIOS selects candidate boot devices using information collected by POST and configuration information from EEPROM, CMOS RAM or, in the earliest PCs, DIP switches. Following the boot priority sequence in effect, BIOS checks each device in order to see if it is bootable. For a disk drive or a device that logically emulates a disk drive, such as a USB flash drive or perhaps a tape drive, to perform this check the BIOS attempts to load the first sector (boot sector) from the disk into RAM at memory address 0x0000:0x7C00. If the sector cannot be read (due to a missing or unformatted disk, or due to a hardware failure), the BIOS considers the device unbootable and proceeds to check the next device. If the sector is read successfully, some BIOSes will also check for the boot sector signature 0x55 0xAA in the last two bytes of the sector (which is 512 bytes long), before accepting a boot sector and considering the device bootable.[nb 1]
The BIOS proceeds to test each device sequentially until a bootable device is found, at which time the BIOS transfers control to the loaded sector with a jump instruction to its first byte at address 0x0000:0x7C00 (exactly 1 KiB below the 32 KiB mark); see MBR invocation and VBR invocation. (This location is one reason that an IBM PC requires at least 32 KiB of RAM in order to be equipped with a disk system; with 31 KiB or less, it would be impossible to boot from any disk, removable or fixed, using the BIOS boot protocol.) Most, but not all, BIOSes load the drive number (as used by INT 13h) of the boot drive into CPU register DL before jumping to the first byte of the loaded boot sector.
Note well that the BIOS does not interpret or process the contents of the boot sector other than to possibly check for the boot sector signature in the last two bytes; all interpretation of data structures like MBR partition tables and so-called BIOS Parameter Blocks is done by the boot program in the boot sector itself or by other programs loaded through the boot process and is beyond the scope of BIOS. Nothing about BIOS predicates these data structures or impedes their replacement or improvement.
A non-disk device such as a network adapter attempts booting by a procedure that is defined by its option ROM or the equivalent integrated into the motherboard BIOS ROM. As such, option ROMs may also influence or supplant the boot process defined by the motherboard BIOS ROM.
Boot priority[edit]
The user can control the boot process, to cause one medium to be booted instead of another when two or more bootable media are present, by taking advantage of the boot priority implemented by the BIOS. For example, most computers have a hard disk that is bootable, but usually there is a removable-media drive that has higher boot priority, so the user can cause a removable disk to be booted, simply by inserting it, without removing the hard disk drive or altering its contents to make it unbootable.
In most modern BIOSes, the boot priority order of all potentially bootable devices can be freely configured by the user through the BIOS configuration utility. In older BIOSes, limited boot priority options are selectable; in the earliest BIOSes, a fixed priority scheme was implemented, with floppy disk drives first, fixed disks (i.e. hard disks) second, and typically no other boot devices supported, subject to modification of these rules by installed option ROMs. The BIOS in an early PC also usually would only boot from the first floppy disk drive or the first hard disk drive, even if there were two drives of either type installed. All more advanced boot priority sequences evolved as incremental improvements on this basic system.
Historically the BIOS would try to boot from a floppy drive first and a hard disk second. The default for CD or DVD booting is an extension of this. With the El Torito optical media boot standard, the optical drive actually emulates a 3.5" high-density floppy disk to the BIOS for boot purposes. Optical disks are a special case, because their lowest level of data organization is typically a fairly high-level file system (e.g. ISO 9660 for CD-ROM).
Reading the "first sector" of a CD-ROM or DVD-ROM is not a simply defined operation like it is on a floppy disk or a hard disk. Furthermore, the complexity of the medium makes it difficult to write a useful boot program in one sector, even though optical media sectors are typically 2048 bytes each, four times the standard 512-byte size of floppy and legacy hard disk sectors. Therefore, optical media booting uses the El Torito standard, which specifies a way for an optical disk to contain an image of a high-density (1.44 MB) floppy disk and for the drive to provide access to this disk image in a simple manner that emulates floppy disk drive operations. Therefore, CD-ROM drives boot as emulated floppy disk drives; the bootable virtual floppy disk can contain software that provides access to the optical medium in its native format.
Boot failure[edit]
The behavior if the BIOS does not find a bootable device has varied as personal computers developed. The original IBM PC and XT had Microsoft Cassette BASIC in ROM, and if no bootable device was found, ROM BASIC was started by calling INT 18h. Therefore, barring a hardware failure, an original IBM PC or XT would never fail to boot, either into BASIC or from disk (or through an option ROM). One model of the original IBM PC was available with no disk drive; a cassette recorder could be attached via the cassette port on the rear, for loading and saving BASIC programs to tape. Since few programs used BASIC in ROM, clone PC makers left it out; then a computer that failed to boot from a disk would display "No ROM BASIC" and halt (in response to INT 18h).
Later computers would display a message like "No bootable disk found"; some would prompt for a disk to be inserted and a key to be pressed, and when a key was pressed they would restart the boot process. A modern BIOS may display nothing or may automatically enter the BIOS configuration utility when the boot process fails. Unlike earlier BIOSes, modern versions are often written with the assumption that if the computer cannot be booted from a hard disk, the user will not have software that they want to boot from removable media instead. (Lately, typically it will only be a specialist computer technician who does that, only to get the computer back into a condition where it can be booted from the hard disk.)
Boot environment[edit]
This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2014) (Learn how and when to remove this template message)
The environment for the boot program is very simple: the CPU is in real mode and the general-purpose and segment registers are undefined, except CS, SS, SP, and DL. CS is always zero and IP is initially 0x7C00. Because boot programs are always loaded at this fixed address, there is no need or motivation for a boot program to be relocatable. DL contains the drive number, as used with INT 13h, of the boot device, unless the BIOS is one that does not set the drive number in DL – and then DL is undefined. SS:SP points to a valid stack that is presumably large enough to support hardware interrupts, but otherwise SS and SP are undefined. (A stack must be already set up in order for interrupts to be serviced, and interrupts must be enabled in order for the system timer-tick interrupt, which BIOS always uses at least to maintain the time-of-day count and which it initializes during POST, to be active and for the keyboard to work. The keyboard works even if the BIOS keyboard service is not called; keystrokes are received and placed in the 15-character type-ahead buffer maintained by BIOS.) The boot program must set up its own stack (or at least MS-DOS 6 acts like it must), because the size of the stack set up by BIOS is unknown and its location is likewise variable; although the boot program can investigate the default stack by examining SS:SP, it is easier and shorter to just unconditionally set up a new stack.
At boot time, all BIOS services are available, and the memory below address 0x00400 contains the interrupt vector table. BIOS POST has initialized the system timers ⟨⟩8253 or 8254 IC), interrupt controller(s), DMA controller(s), and other motherboard/chipset hardware as necessary to bring all BIOS services to ready status. DRAM refresh for all system DRAM in conventional memory and extended memory, but not necessarily expanded memory, has been set up and is running. The interrupt vectors corresponding to the BIOS interrupts have been set to point at the appropriate entry points in the BIOS, hardware interrupt vectors for devices initialized by the BIOS have been set to point to the BIOS-provided ISRs, and some other interrupts, including ones that BIOS generates for programs to hook, have been set to a default dummy ISR that immediately returns. The BIOS maintains a reserved block of system RAM at addresses 0x00400–0x004FF with various parameters initialized during the POST. All memory at and above address 0x00500 can be used by the boot program; it may even overwrite itself.
Extensions (option ROMs)[edit]
Peripheral cards such as some hard disk drive controllers and some video display adapters have their own BIOS extension option ROMs, which provide additional functionality to BIOS. Code in these extensions runs before the BIOS boots the system from mass storage. These ROMs typically test and initialize hardware, add new BIOS services, and augment or replace existing BIOS services with their own versions of those services. For example, a SCSI controller usually has a BIOS extension ROM that adds support for hard drives connected through that controller. Some video cards have extension ROMs that replace the video services of the motherboard BIOS with their own video services. BIOS extension ROMs gain total control of the machine, so they can in fact do anything, and they may never return control to the BIOS that invoked them. An extension ROM could in principle contain an entire operating system or an application program, or it could implement an entirely different boot process such as booting from a network. Operation of an IBM-compatible computer system can be completely changed by removing or inserting an adapter card (or a ROM chip) that contains a BIOS extension ROM.
The motherboard BIOS typically contains code to access hardware components necessary for bootstrapping the system, such as the keyboard, display, and storage. In addition, plug-in adapter cards such as SCSI, RAID, network interface cards, and video boards often include their own BIOS (e.g. Video BIOS), complementing or replacing the system BIOS code for the given component. Even devices built into the motherboard can behave in this way; their option ROMs can be stored as separate code on the main BIOS flash chip, and upgraded either in tandem with, or separately from, the main BIOS.
An add-in card requires an option ROM if the card is not supported by the main BIOS and the card needs to be initialized or made accessible through BIOS services before the operating system can be loaded (usually this means it is required in the bootstrapping process). Even when it is not required, an option ROM can allow an adapter card to be used without loading driver software from a storage device after booting begins – with an option ROM, no time is taken to load the driver, the driver does not take up space in RAM nor on hard disk, and the driver software on the ROM always stays with the device so the two cannot be accidentally separated. Also, if the ROM is on the card, both the peripheral hardware and the driver software provided by the ROM are installed together with no extra effort to install the software. An additional advantage of ROM on some early PC systems (notably including the IBM PCjr) was that ROM was faster than main system RAM. (On modern systems, the case is very much the reverse of this, and BIOS ROM code is usually copied ("shadowed") into RAM so it will run faster.)
There are many methods and utilities for examining the contents of various motherboard BIOS and expansion ROMs, such as Microsoft DEBUG or the Unix dd.
Boot procedure[edit]
If an expansion ROM wishes to change the way the system boots (such as from a network device or a SCSI adapter for which the BIOS has no driver code) in a cooperative way, it can use the BIOS Boot Specification (BBS) API to register its ability to do so. Once the expansion ROMs have registered using the BBS APIs, the user can select among the available boot options from within the BIOS's user interface. This is why most BBS compliant PC BIOS implementations will not allow the user to enter the BIOS's user interface until the expansion ROMs have finished executing and registering themselves with the BBS API.[citation needed] The specification can be downloaded from the ACPICA website. The official title is BIOS Boot Specification (Version 1.01, 11 January 1996).[14]
Also, if an expansion ROM wishes to change the way the system boots unilaterally, it can simply hook INT 19h or other interrupts normally called from interrupt 19h, such as INT 13h, the BIOS disk service, to intercept the BIOS boot process. Then it can replace the BIOS boot process with one of its own, or it can merely modify the boot sequence by inserting its own boot actions into it, by preventing the BIOS from detecting certain devices as bootable, or both. Before the BIOS Boot Specification was promulgated, this was the only way for expansion ROMs to implement boot capability for devices not supported for booting by the native BIOS of the motherboard.[citation needed]
Initialization[edit]
After the motherboard BIOS completes its POST, most BIOS versions search for option ROM modules, also called BIOS extension ROMs, and execute them. The motherboard BIOS scans for extension ROMs in a portion of the "upper memory area" (the part of the x86 real-mode address space at and above address 0xA0000) and runs each ROM found, in order. To discover memory-mapped ISA option ROMs, a BIOS implementation scans the real-mode address space from 0x0C0000 to 0x0F0000 on 2 KiB boundaries, looking for a two-byte ROM signature: 0x55 followed by 0xAA. In a valid expansion ROM, this signature is followed by a single byte indicating the number of 512-byte blocks the expansion ROM occupies in real memory, and the next byte is the option ROM's entry point (also known as its "entry offset"). A checksum of the specified number of 512-byte blocks is calculated, and if the ROM has a valid checksum, the BIOS transfers control to the entry address, which in a normal BIOS extension ROM should be the beginning of the extension's initialization routine.
At this point, the extension ROM code takes over, typically testing and initializing the hardware it controls and registering interrupt vectors for use by post-boot applications. It may use BIOS services (including those provided by previously initialized option ROMs) to provide a user configuration interface, to display diagnostic information, or to do anything else that it requires. While the actions mentioned are typical behaviors of BIOS extension ROMs, each option ROM receives total control of the computer and may do anything at all, as noted with more detail in the Extensions section below; it is possible that an option ROM will not return to BIOS, pre-empting the BIOS's boot sequence altogether.
An option ROM should normally return to the BIOS after completing its initialization process. Once (and if) an option ROM returns, the BIOS continues searching for more option ROMs, calling each as it is found, until the entire option ROM area in the memory space has been scanned.
Physical placement[edit]
Option ROMs normally reside on adapter cards. However, the original PC, and perhaps also the PC XT, have a spare ROM socket on the motherboard (the "system board" in IBM's terms) into which an option ROM can be inserted, and the four ROMs that contain the BASIC interpreter can also be removed and replaced with custom ROMs which can be option ROMs. The IBM PCjr is unique among PCs in having two ROM cartridge slots on the front. Cartridges in these slots map into the same region of the upper memory area used for option ROMs, and the cartridges can contain option ROM modules that the BIOS would recognize. The cartridges can also contain other types of ROM modules, such as BASIC programs, that are handled differently. One PCjr cartridge can contain several ROM modules of different types, possibly stored together in one ROM chip.
Operating system services[edit]
The BIOS ROM is customized to the particular manufacturer's hardware, allowing low-level services (such as reading a keystroke or writing a sector of data to diskette) to be provided in a standardized way to programs, including operating systems. For example, an IBM PC might have either a monochrome or a color display adapter (using different display memory addresses and hardware), but a single, standard, BIOS system call may be invoked to display a character at a specified position on the screen in text mode or graphics mode.
The BIOS provides a small library of basic input/output functions to operate peripherals (such as the keyboard, rudimentary text and graphics display functions and so forth). When using MS-DOS, BIOS services could be accessed by an application program (or by MS-DOS) by executing an INT 13h interrupt instruction to access disk functions, or by executing one of a number of other documented BIOS interrupt calls to access video display, keyboard, cassette, and other device functions.
Operating systems and executive software that are designed to supersede this basic firmware functionality provide replacement software interfaces to application software. Applications can also provide these services to themselves. This began even in the 1980s under MS-DOS, when programmers observed that using the BIOS video services for graphics display was very slow. To increase the speed of screen output, many programs bypassed the BIOS and programmed the video display hardware directly. Other graphics programmers, particularly but not exclusively in the demoscene, observed that there were technical capabilities of the PC display adapters that were not supported by the IBM BIOS and could not be taken advantage of without circumventing it. Since the AT-compatible BIOS ran in Intel real mode, operating systems that ran in protected mode on 286 and later processors required hardware device drivers compatible with protected mode operation to replace BIOS services.
In modern personal computers running modern operating systems the BIOS is used only during booting and initial loading of system software. Before the operating system's first graphical screen is displayed, input and output are typically handled through BIOS. A boot menu such as the textual menu of Windows, which allows users to choose an operating system to boot, to boot into the safe mode, or to use the last known good configuration, is displayed through BIOS and receives keyboard input through BIOS.[citation needed]
Most modern PCs can still boot and run legacy operating systems such as MS-DOS or DR-DOS that rely heavily on BIOS for their console and disk I/O, providing that the system has a BIOS or BIOS-compatible firmware, which is not necessarily the case with UEFI-based PCs.
Processor microcode updates[edit]
Intel processors have reprogrammable microcode since the P6 microarchitecture.[15][16] The BIOS may contain patches to the processor microcode that fix errors in the initial processor microcode; reprogramming is not persistent, thus loading of microcode updates is performed each time the system is powered up. Without reprogrammable microcode, an expensive processor swap would be required;[17] for example, the Pentium FDIV bug became an expensive fiasco for Intel as it required a product recall because the original Pentium processor's defective microcode could not be reprogrammed.
Identification[edit]
Some BIOSes contain a software licensing description table (SLIC), a digital signature placed inside the BIOS by the original equipment manufacturer (OEM), for example Dell. The SLIC is inserted into the ACPI table and contains no active code.[18][19]
Computer manufacturers that distribute OEM versions of Microsoft Windows and Microsoft application software can use the SLIC to authenticate licensing to the OEM Windows Installation disk and system recovery disc containing Windows software. Systems with an SLIC can be preactivated with an OEM product key, and they verify an XML formatted OEM certificate against the SLIC in the BIOS as a means of self-activating (see System Locked Preinstallation, SLP). If a user performs a fresh install of Windows, they will need to have possession of both the OEM key (either SLP or COA) and the digital certificate for their SLIC in order to bypass activation.[18] This can be achieved if the user performs a restore using a pre-customised image provided by the OEM. Power users can copy the necessary certificate files from the OEM image, decode the SLP product key, then perform SLP activation manually. Cracks for non-genuine Windows distributions usually edit the SLIC or emulate it in order to bypass Windows activation.[citation needed]
Overclocking[edit]
Some BIOS implementations allow overclocking, an action in which the CPU is adjusted to a higher clock rate than its manufacturer rating for guaranteed capability. Overclocking may, however, seriously compromise system reliability in insufficiently cooled computers and generally shorten component lifespan. Overclocking, when incorrectly performed, may also cause components to overheat so quickly that they mechanically destroy themselves.[20]
Modern use[edit]
Some operating systems, for example MS-DOS, rely on the BIOS to carry out most input/output tasks within the PC.[21]
Because the BIOS still runs in 16-bit real mode, calling BIOS services directly is inefficient for protected-mode operating systems. BIOS services are not used by modern multitasking operating systems after they initially load, so the importance of the primary part of BIOS is greatly reduced from what it was initially.
Later BIOS implementations took on more complex functions, by including interfaces such as Advanced Configuration and Power Interface (ACPI); these functions include power management, hot swapping, and thermal management. At the same time, since 2010, BIOS technology is in a transitional process toward UEFI.[4]
Configuration[edit]
Setup utility[edit]
Historically, the BIOS in the IBM PC and XT had no built-in user interface. The BIOS versions in earlier PCs (XT-class) were not software configurable; instead, users set the options via DIP switches on the motherboard. Later computers, including all IBM-compatibles with 80286 CPUs, had a battery-backed nonvolatile BIOS memory (CMOS RAM chip) that held BIOS settings.[22] These settings, such as video-adapter type, memory size, and hard-disk parameters, could only be configured by running a configuration program from a disk, not built into the ROM. A special "reference diskette" was inserted in an IBM AT to configure settings such as memory size.
Early BIOS versions did not have passwords or boot-device selection options. The BIOS was hard-coded to boot from the first floppy drive, or, if that failed, the first hard disk. Access control in early AT-class machines was by a physical keylock switch (which was not hard to defeat if the computer case could be opened). Anyone who could switch on the computer could boot it.[citation needed]
Later, 386-class computers started integrating the BIOS setup utility in the ROM itself, alongside the BIOS code; these computers usually boot into the BIOS setup utility if a certain key or key combination is pressed, otherwise the BIOS POST and boot process are executed.
Award BIOS setup utility on a standard PC
A modern BIOS setup utility has a menu-based user interface (UI) accessed by pressing a certain key on the keyboard when the PC starts. Usually the key is advertised for short time during the early startup, for example "Press F1 to enter CMOS setup". The actual key depends on specific hardware. Features present in the BIOS setup utility typically include:
Configuring the hardware components, including setting their various operating modes and frequencies (for example, selecting how the storage controllers are visible to the operating system, or overlocking the CPU)
Setting the system clock
Enabling or disabling system components
Selecting which devices are potential boot devices, and in which order booting from them will be attempted
Setting various passwords, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized portable storage devices, a password for booting the system, or a hard disk drive password that limits access to it and stays assigned even if the hard disk drive is moved to another computer
Reprogramming[edit]
In modern PCs the BIOS is stored in rewritable memory, allowing the contents to be replaced and modified. This rewriting of the contents is sometimes termed flashing, based on the common use of a kind of EEPROM known technically as "flash EEPROM" and colloquially as "flash memory". It can be done by a special program, usually provided by the system's manufacturer, or at POST, with a BIOS image in a hard drive or USB flash drive. A file containing such contents is sometimes termed "a BIOS image". A BIOS might be reflashed in order to upgrade to a newer version to fix bugs or provide improved performance or to support newer hardware, or a reflashing operation might be needed to fix a damaged BIOS.
Hardware[edit]
American Megatrends BIOS 686. This BIOS chip is housed in a PLCC package in a socket.
The original IBM PC BIOS (and cassette BASIC) was stored on mask-programmed read-only memory (ROM) chips in sockets on the motherboard. ROMs could be replaced, but not altered, by users. To allow for updates, many compatible computers used re-programmable memory devices such as EPROM and later flash memory devices. According to Robert Braver, the president of the BIOS manufacturer Micro Firmware, Flash BIOS chips became common around 1995 because the electrically erasable PROM (EEPROM) chips are cheaper and easier to program than standard ultraviolet erasable PROM (EPROM) chips. Flash chips are programmed (and re-programmed) in-circuit, while EPROM chips need to be removed from the motherboard for re-programming.[23] BIOS versions are upgraded to take advantage of newer versions of hardware and to correct bugs in previous revisions of BIOSes.[24]
Beginning with the IBM AT, PCs supported a hardware clock settable through BIOS. It had a century bit which allowed for manually changing the century when the year 2000 happened. Most BIOS revisions created in 1995 and nearly all BIOS revisions in 1997 supported the year 2000 by setting the century bit automatically when the clock rolled past midnight, December 31, 1999.[25]
The first flash chips were attached to the ISA bus. Starting in 1997, the BIOS flash moved to the LPC bus, a functional replacement for ISA, following a new standard implementation known as "firmware hub" (FWH). In 2006, the first systems supporting a Serial Peripheral Interface (SPI) appeared, and the BIOS flash memory moved again.[citation needed]
The size of the BIOS, and the capacity of the ROM, EEPROM, or other media it may be stored on, has increased over time as new features have been added to the code; BIOS versions now exist with sizes up to 16 megabytes. For contrast, the original IBM PC BIOS was contained in an 8 KiB mask ROM. Some modern motherboards are including even bigger NAND flash memory ICs on board which are capable of storing whole compact operating systems, such as some Linux distributions. For example, some ASUS motherboards included Splashtop Linux embedded into their NAND flash memory ICs.[26] However, the idea of including an operating system along with BIOS in the ROM of a PC is not new; in the 1980s, Microsoft offered a ROM option for MS-DOS, and it was included in the ROMs of some PC clones such as the Tandy 1000 HX.
Another type of firmware chip was found on the IBM PC AT and early compatibles. In the AT, the keyboard interface was controlled by a microcontroller with its own programmable memory. On the IBM AT, that was a 40-pin socketed device, while some manufacturers used an EPROM version of this chip which resembled an EPROM. This controller was also assigned the A20 gate function to manage memory above the one-megabyte range; occasionally an upgrade of this "keyboard BIOS" was necessary to take advantage of software that could use upper memory.[citation needed]
The BIOS may contain components such as the Memory Reference Code (MRC), which is responsible for handling memory timings and related hardware settings.[27]:8[28]
Vendors and products[edit]
Comparison of different BIOS implementations
Company
AwardBIOS AMIBIOS Insyde SeaBIOS
License
Proprietary Proprietary Proprietary LGPL v3
Maintained / developed
Yes Yes Yes Yes
32-bit PCI BIOS calls
Yes Yes Yes Yes
AHCI
Yes Yes Yes Yes
APM
Yes Yes Yes (1.2) Yes (1.2)
BBS
Yes Yes Yes Yes
Boot menu
Yes Yes Yes Yes
Compression
Yes (LHA[29]) Yes (LHA) Yes (RLE) Yes (LZMA)
CMOS
Yes Yes Yes Yes
EDD
Yes Yes Yes Yes (3.0)
ESCD
Yes Yes ? No
Flash from ROM
? Yes ? No
Language
Assembly Assembly Assembly C
LBA
Yes (48) Yes (48) Yes Yes (48)
MultiProcessor Specification
Yes Yes Yes Yes
Option ROM
Yes Yes Yes Yes
Password
Yes Yes Yes No
PMM
? Yes ? Yes
Setup screen
Yes Yes Yes No
SMBIOS
Yes Yes Yes Yes (2.4)
Splash screen
Yes (EPA)[30] Yes (PCX) Yes Yes (BMP, JPG)
TPM
Unknown Unknown Unknown Some
USB booting
Yes Yes Yes Yes
USB hub
? ? ? Yes
USB keyboard
Yes Yes Yes Yes
USB mouse
Yes Yes Yes Yes
IBM published the entire listings of the BIOS for its original PC, PC XT, PC AT, and other contemporary PC models, in an appendix of the IBM PC Technical Reference Manual for each machine type. The effect of the publication of the BIOS listings is that anyone can see exactly what a definitive BIOS does and how it does it.
In May 1984 Phoenix Software Associates released its first ROM-BIOS which enabled OEMs to build essentially 100%-compatible clones without having to reverse-engineer the IBM PC BIOS themselves, as Compaq had done for the Portable, helping fuel the growth in the PC compatibles industry and sales of non-IBM versions of DOS.[31] And the first American Megatrends (AMI) BIOS was released on 1986.
New standards grafted onto the BIOS are usually without complete public documentation or any BIOS listings. As a result, it is not as easy to learn the intimate details about the many non-IBM additions to BIOS as about the core BIOS services.
Most PC motherboard suppliers license a BIOS "core" and toolkit from a commercial third-party, known as an "independent BIOS vendor" or IBV. The motherboard manufacturer then customizes this BIOS to suit its own hardware. For this reason, updated BIOSes are normally obtained directly from the motherboard manufacturer. Major BIOS vendors include American Megatrends (AMI), Insyde Software, Phoenix Technologies and Byosoft. Former vendors include Award Software and Microid Research that were acquired by Phoenix Technologies in 1998; Phoenix later phased out the Award Brand name. General Software, which was also acquired by Phoenix in 2007, sold BIOS for Intel processor based embedded systems.
The open source community increased their effort to develop a replacement for proprietary BIOSes and their future incarnations with an open sourced counterpart through the libreboot, coreboot and OpenBIOS/Open Firmware projects. AMD provided product specifications for some chipsets, and Google is sponsoring the project. Motherboard manufacturer Tyan offers coreboot next to the standard BIOS with their Opteron line of motherboards. MSI and Gigabyte Technology have followed suit with the MSI K9ND MS-9282 and MSI K9SD MS-9185 resp. the M57SLI-S4 models.
Security[edit]
An American Megatrends BIOS showing a "Intel CPU uCode Loading Error" after a failed attempt to upload microcode patches into the CPU
A detached BIOS chip
EEPROM chips are advantageous because they can be easily updated by the user; it is customary for hardware manufacturers to issue BIOS updates to upgrade their products, improve compatibility and remove bugs. However, this advantage had the risk that an improperly executed or aborted BIOS update could render the computer or device unusable. To avoid these situations, more recent BIOSes use a "boot block"; a portion of the BIOS which runs first and must be updated separately. This code verifies if the rest of the BIOS is intact (using hash checksums or other methods) before transferring control to it. If the boot block detects any corruption in the main BIOS, it will typically warn the user that a recovery process must be initiated by booting from removable media (floppy, CD or USB flash drive) so the user can try flashing the BIOS again. Some motherboards have a backup BIOS (sometimes referred to as DualBIOS boards) to recover from BIOS corruptions.
There are at least four known BIOS attack viruses, two of which were for demonstration purposes. The first one found in the wild was Mebromi, targeting Chinese users.
The first BIOS virus was CIH, whose name matches the initials of its creator, Chen Ing Hau. CIH was also called the "Chernobyl Virus", because its payload date was 1999-04-26, the 13th anniversary of the Chernobyl accident. CIH appeared in mid-1998 and became active in April 1999. It was able to erase flash ROM BIOS content. Often, infected computers could no longer boot, and people had to remove the flash ROM IC from the motherboard and reprogram it. CIH targeted the then-widespread Intel i430TX motherboard chipset and took advantage of the fact that the Windows 9x operating systems, also widespread at the time, allowed direct hardware access to all programs.
Modern systems are not vulnerable to CIH because of a variety of chipsets being used which are incompatible with the Intel i430TX chipset, and also other flash ROM IC types. There is also extra protection from accidental BIOS rewrites in the form of boot blocks which are protected from accidental overwrite or dual and quad BIOS equipped systems which may, in the event of a crash, use a backup BIOS. Also, all modern operating systems such as FreeBSD, Linux, macOS, Windows NT-based Windows OS like Windows 2000, Windows XP and newer, do not allow user-mode programs to have direct hardware access.
As a result, as of 2008, CIH has become essentially harmless, at worst causing annoyance by infecting executable files and triggering antivirus software. Other BIOS viruses remain possible, however;[32] since most Windows home users without Windows Vista/7's UAC run all applications with administrative privileges, a modern CIH-like virus could in principle still gain access to hardware without first using an exploit. The operating system OpenBSD prevents all users from having this access and the grsecurity patch for the linux kernel also prevents this direct hardware access by default, the difference being an attacker requiring a much more difficult kernel level exploit or reboot of the machine.
The second BIOS virus was a technique presented by John Heasman, principal security consultant for UK-based Next-Generation Security Software. In 2006, at the Black Hat Security Conference, he showed how to elevate privileges and read physical memory, using malicious procedures that replaced normal ACPI functions stored in flash memory.
The third BIOS virus was a technique called "Persistent BIOS infection." It appeared in 2009 at the CanSecWest Security Conference in Vancouver, and at the SyScan Security Conference in Singapore. Researchers Anibal Sacco[33] and Alfredo Ortega, from Core Security Technologies, demonstrated how to insert malicious code into the decompression routines in the BIOS, allowing for nearly full control of the PC at start-up, even before the operating system is booted. The proof-of-concept does not exploit a flaw in the BIOS implementation, but only involves the normal BIOS flashing procedures. Thus, it requires physical access to the machine, or for the user to be root. Despite these requirements, Ortega underlined the profound implications of his and Sacco's discovery: "We can patch a driver to drop a fully working rootkit. We even have a little code that can remove or disable antivirus."[34]
Mebromi is a trojan which targets computers with AwardBIOS, Microsoft Windows, and antivirus software from two Chinese companies: Rising Antivirus and Jiangmin KV Antivirus.[35][36][37] Mebromi installs a rootkit which infects the master boot record.
In a December 2013 interview with 60 Minutes, Deborah Plunkett, Information Assurance Director for the US National Security Agency claimed that NSA analysts had uncovered and thwarted a possible BIOS attack by a foreign nation state. The attack on the world's computers could have allegedly "literally taken down the US economy." The segment further cites anonymous cyber security experts briefed on the operation as alleging the plot was conceived in China.[38] A later article in The Guardian cast doubt on the likelihood of such a threat, quoting Berkeley computer-science researcher Nicholas Weaver, Matt Blaze, a computer and information sciences professor at the University of Pennsylvania, and cybersecurity expert Robert David Graham in an analysis of the NSA's claims.[39]
Alternatives and successors[edit]
For comparable software on other computer systems, see booting.
As of 2011[update], the BIOS is being replaced by the more complex Extensible Firmware Interface (EFI) in many new machines. EFI is a specification which replaces the runtime interface of the legacy BIOS. Initially written for the Intel Itanium architecture, EFI is now available for x86 and x86-64 platforms; the specification development is driven by The Unified EFI Forum, an industry Special Interest Group. EFI booting has been supported in only Microsoft Windows versions supporting GPT,[40] the Linux kernel 2.6.1 and later, and macOS on Intel-based Macs.[41] As of 2014[update], new PC hardware predominantly ships with UEFI firmware. The architecture of the rootkit safeguard can also prevent the system from running the user's own software changes, which makes UEFI controversial as a BIOS replacement in the open hardware community.
Other alternatives to the functionality of the "Legacy BIOS" in the x86 world include coreboot and libreboot.
Some servers and workstations use a platform-independent Open Firmware (IEEE-1275) based on the Forth programming language; it is included with Sun's SPARC computers, IBM's RS/6000 line, and other PowerPC systems such as the CHRP motherboards, along with the x86-based OLPC XO-1.
As of at least 2015, Apple has removed legacy BIOS support from MacBook Pro computers. As such the bless utility no longer supports the --legacy switch, and prints "Legacy mode not supported on this system". These Macs also cannot boot from CD-ROM or USB flash drives.
See also[edit]
Computing portal
Unified Extensible Firmware Interface (UEFI)
e820
Extended System Configuration Data (ESCD)
Double boot
Legacy Plug and Play (PnP) – specifications supporting automated configuration of hardware devices, primarily those on the ISA bus
Ralf Brown's Interrupt List (RBIL) – interrupts, calls, interfaces, data structures, memory and port addresses, and processor opcodes for the x86 architecture
System Management BIOS (SMBIOS)
VESA BIOS Extensions (VBE) – an interface for using compliant video boards at high resolutions and bit depths, beyond the standard BIOS support
Fujitsu TBIOS (on Fujitsu FM Towns computers)
Notes[edit]
Jump up ^ The signature at offset +0x1FE in boot sectors is 0x55 0xAA, that is 0x55 at offset +0x1FE and 0xAA at offset +0x1FF. Since little-endian representation must be assumed in the context of IBM PC compatible machines, this can be written as 16-bit word 0xAA55 in programs for x86 processors (note the swapped order), whereas it would have to be written as 0x55AA in programs for other CPU architectures using a big-endian representation. Since this has been mixed up numerous times in books and even in original Microsoft reference documents, this article uses the offset-based byte-wise on-disk representation to avoid any possible misinterpretation.
References[edit]
Jump up ^ "Ref — System BIOS". PCGuide. Retrieved 6 December 2014.
^ Jump up to: a b c Kildall, Gary A. (June 1975), CP/M 1.1 or 1.2 BIOS and BDOS for Lawrence Livermore Laboratories
^ Jump up to: a b c d Kildall, Gary A. (January 1980). "The History of CP/M, THE EVOLUTION OF AN INDUSTRY: ONE PERSON'S VIEWPOINT" (Vol. 5, No. 1, Number 41 ed.). Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. pp. 6–7. Retrieved 2013-06-03.
^ Jump up to: a b Bradley, Tony. "R.I.P. BIOS: A UEFI Primer". PCWorld. Retrieved 2014-01-27.
Jump up ^ Swaine, Michael (1997-04-01). "Gary Kildall and Collegial Entrepreneurship". Dr. Dobb's Journal. Retrieved 2006-11-20.
Jump up ^ Shustek, Len (2016-08-02). "In His Own Words: Gary Kildall". Remarkable People. Computer History Museum.
^ Jump up to: a b Killian, A. Joseph "Joe" (2001). "Gary Kildall's CP/M: Some early CP/M history - 1976-1977". Thomas "Todd" Fischer, IMSAI. Retrieved 2013-06-03.
^ Jump up to: a b Fraley, Bob; Spicer, Dag (2007-01-26). "Oral History of Joseph Killian, Interviewed by: Bob Fraley, Edited by: Dag Spicer, Recorded: January 26, 2007, Mountain View, California, CHM Reference number: X3879.2007," (PDF). Computer History Museum. Retrieved 2013-06-03.
Jump up ^ "HP BIOS Configuration Utility". Hewlett-Packard. 2013. Retrieved 2015-01-12.
Jump up ^ See Intel® 64 and IA-32 Architectures Software Developer’s Manual, volume 3, section 9.1.2
Jump up ^ page 5-27 IBM Personal Computer Hardware Reference Library Technical Reference, 1984, publication number 6361459
Jump up ^ "IBM 5162 PC XT286 TechRef 68X2537 Technical Reference manual" (PDF). August 1986. p. 35 (System BIOS A-5). Retrieved 2014-12-11.
Jump up ^ How StuffWorks: What BIOS Does.
Jump up ^ BIOS Boot Specification (Version 1.01, 11 January 1996) Archived April 22, 2012, at the Wayback Machine.
Jump up ^ Mueller, Scott (2001-06-08). "Processor Update Feature | Microprocessor Types and Specifications". InformIT. Retrieved 2014-04-15.
Jump up ^ "Linux* Processor Microcode Data File". Download Center. Downloadcenter.intel.com. 2009-09-23. Retrieved 2014-04-15.
Jump up ^ Scott Mueller, Upgrading and repairing PCs 15th edition, Que Publishing, 2003 ISBN 0-7897-2974-1, pages 109-110
^ Jump up to: a b "How SLP and SLIC Works". guytechie.com. 2010-02-25. Retrieved 2015-02-03.
Jump up ^ "Create and add an OEM ACPI SLIC table module to a congatec BIOS" (PDF). congatec.com. 2011-06-16. Retrieved 2015-02-03.
Jump up ^ Whitson Gordon. "A Beginner's Introduction to Overclocking Your Intel Processor". Lifehacker. Gawker Media. Retrieved 6 December 2014.
Jump up ^ Smart Computing Article - What Is The BIOS? Archived 2012-03-10 at the Wayback Machine. - Computing Basics July 1994 • Vol.5 Issue 7
Jump up ^ Torres, Gabriel (24 November 2004). "Introduction and Lithium Battery". Replacing the Motherboard Battery. hardwaresecrets.com. Archived from the original on 24 December 2013. Retrieved June 20, 2013.
Jump up ^ "Decoding RAM & ROM." Smart Computing. June 1997. Volume 8, Issue 6.
Jump up ^ "Upgrading Your Flash BIOS For Plug And Play." Smart Computing. March 1996. Volume 7, Issue 3.
Jump up ^ "Time To Check BIOS." Smart Computing. April 1999. Volume 7, Issue 4.
Jump up ^ SplashTop's Instant-On Linux Desktop | Geek.com
Jump up ^ Posted by Alex Watson, possibly repost from original content on custompc.com [unclear]. "The life and times of the modern motherboard". 2007-11-27. Retrieved 2 February 2013.
Jump up ^ David Hilber, Jr. (August 2009). "Considerations for Designing an Embedded Intel Architecture System with System Memory Down ®" (PDF). Intel. Retrieved 2 February 2013.
Jump up ^ Stiller, Andreas (2001). "Prozessor-Patches". c't (in German). Heise (5): 240. Retrieved 2015-11-21.
Jump up ^ "Award BIOS logo". 2015-06-15. Retrieved 2015-12-06.
Jump up ^ Phoenix Eagerly Waiting to Clone Next-Generation IBM BIOS, InfoWorld, March 9, 1987
Jump up ^ New BIOS Virus Withstands HDD Wipes, March 27, 2009. Marcus Yam. Tom's Hardware US
Jump up ^ Sacco, Anibal; Alfredo Ortéga. "Persistent BIOS Infection". Exploiting Stuff. Retrieved 2010-02-06.
Jump up ^ Fisher, Dennis. "Researchers unveil persistent BIOS attack methods". Threat Post. Archived from the original on 30 January 2010. Retrieved 2010-02-06.
Jump up ^ Giuliani, Marco. "Mebromi: the first BIOS rootkit in the wild". blog. Retrieved 2011-09-19.
Jump up ^ "360发布"BMW病毒"技术分析报告". blog. Archived from the original on 2011-09-25. Retrieved 2011-09-19.
Jump up ^ Yuan, Liang. "Trojan.Mebromi". Threat Response. Retrieved 2011-09-19.
Jump up ^ "How did 60 Minutes get cameras into a spy agency?". CBS News. Retrieved 2014-04-15.
Jump up ^ Spencer Ackerman in Washington (2013-12-16). "NSA goes on 60 Minutes: the definitive facts behind CBS's flawed report | World news". theguardian.com. Retrieved 2014-01-27.
Jump up ^ "Windows and GPT FAQ". microsoft.com. Microsoft. Retrieved 6 December 2014.
Jump up ^ "Extensible Firmware Interface (EFI) and Unified EFI (UEFI)". Intel. Retrieved 6 December 2014.
Further reading[edit]
IBM Personal Computer Technical Reference (Revised ed.). IBM Corporation. March 1983.
IBM Personal Computer AT Technical Reference. IBM Personal Computer Hardware Reference Library. 0, 1, 2 (Revised ed.). IBM Corporation. March 1986 [1984-03]. 1502494, 6139362, 6183310, 6183312, 6183355, 6280070, 6280099.
Phoenix Technologies, Ltd. (1989) [1987]. System BIOS for IBM PC/XT/AT Computers and Compatibles — The Complete Guide to ROM-Based System Software. Phoenix Technical Reference Series (1st ed.). Addison Wesley Publishing Company, Inc. ISBN 0-201-51806-6.
Phoenix Technologies, Ltd. (1989) [1987]. CBIOS for IBM PS/2 Computers and Compatibles — The Complete Guide to ROM-Based System Software for DOS. Phoenix Technical Reference Series (1st ed.). Addison Wesley Publishing Company, Inc. ISBN 0-201-51804-X.
Phoenix Technologies, Ltd. (1989) [1987]. ABIOS for IBM PS/2 Computers and Compatibles — The Complete Guide to ROM-Based System Software for OS/2. Phoenix Technical Reference Series (1st ed.). Addison Wesley Publishing Company, Inc. ISBN 0-201-51805-8.
Phoenix Technologies, Ltd. (June 1991). System BIOS for IBM PCs, Compatibles, and EISA Computers — The Complete Guide to ROM-Based System Software. Phoenix Technical Reference Series (2nd ed.). Amsterdam: Addison Wesley Publishing Company, Inc. ISBN 0-201-57760-7.
BIOS Disassembly Ninjutsu Uncovered, 1st edition, a freely available book in PDF format
More Power To Firmware, free bonus chapter to the Mac OS X Internals: A Systems Approach book
External links[edit]
Wikimedia Commons has media related to the BIOS.
Look up BIOS in Wiktionary, the free dictionary.
List of BIOS options
How BIOS Works
Persistent BIOS Infection, Phrack #66, June 1, 2009, archived from the original on April 30, 2011
Preventing BIOS Failures Using Intel Boot Block Flash Memory, Intel, December 1998, archived from the original on March 29, 2007
BIOS Boot Specification 1.01, January 11, 1996
Implementing a Plug and Play BIOS Using Intel's Boot Block Flash Memory, Intel, February 1995, archived from the original on November 28, 2007
Retrieved from "https://en.wikipedia.org/w/index.php?title=BIOS&oldid=815370006"
Categories:
BIOS
Boot loaders
CP/M technology
DOS technology
Hidden categories:
All articles lacking reliable references
Articles lacking reliable references from December 2014
Webarchive template wayback links
CS1 German-language sources (de)
All articles with unsourced statements
Articles with unsourced statements from September 2015
Articles needing additional references from October 2014
All articles needing additional references
Articles with unsourced statements from October 2008
Articles with unsourced statements from October 2014
Articles with unsourced statements from February 2015
Articles with unsourced statements from March 2013
Articles containing potentially dated statements from 2011
All articles containing potentially dated statements
Articles containing potentially dated statements from 2014
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Article
Talk
Variants
Views
Read
Edit
View history
More
Search
Navigation
Main page
Contents
Featured content
Current events
Random article
Donate to Wikipedia
Wikipedia store
Interaction
Help
About Wikipedia
Community portal
Recent changes
Contact page
Tools
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Wikidata item
Cite this page
Print/export
Create a book
Download as PDF
Printable version
In other projects
Wikimedia Commons
Languages
Afrikaans
العربية
Azərbaycanca
Беларуская
Беларуская (тарашкевіца)
Български
Bosanski
Brezhoneg
Català
Čeština
Dansk
Deutsch
Eesti
Ελληνικά
Español
Esperanto
Euskara
فارسی
Français
Galego
한국어
हिन्दी
Hrvatski
Bahasa Indonesia
Íslenska
Italiano
עברית
ქართული
Қазақша
Kurdî
Latviešu
Lëtzebuergesch
Lietuvių
Lumbaart
Magyar
മലയാളം
Bahasa Melayu
Nederlands
日本語
Norsk
Norsk nynorsk
Oʻzbekcha/ўзбекча
Polski
Português
Română
Русский
Scots
Shqip
Simple English
Slovenčina
Slovenščina
کوردی
Српски / srpski
Srpskohrvatski / српскохрватски
Suomi
Svenska
Tagalog
தமிழ்
తెలుగు
ไทย
Türkçe
Українська
Tiếng Việt
中文
Edit links
This page was last edited on 14 December 2017, at 12:24.
Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Privacy policy
About Wikipedia
Disclaimers
Contact Wikipedia
Developers
Cookie statement
Mobile view
Enable previews

values: mw-page-base noprint

values: mw-head-base noprint

values: firstHeading firstHeading en

values: siteSub noprint

values: jump-to-nav mw-jump

values:
/wiki/Bios_(disambiguation)
mw-redirect mw-disambig
Bios (disambiguation)

attrs: role class

values:
note
hatnote navigation-not-searchable

value: b

value: i

values:
/wiki/Reverse_engineer
mw-redirect
Reverse engineer

values:
/wiki/Boot_loader
mw-redirect
Boot loader

values:
/wiki/Hardware_abstraction_layer
mw-redirect
Hardware abstraction layer

values: color:#b2b7f2; font-size:3.3em; font-family:'Times New Roman',serif; font-weight:bold; padding:4px 2px 2px; width:0.5em; line-height: 1em;

values: color:#b2b7f2; font-size:3.3em; font-family:'Times New Roman',serif; font-weight:bold; padding:4px 2px 2px; text-align:right; vertical-align:bottom; width:0.5em; line-height: 1em;

values:
/wiki/Lawrence_Livermore_Laboratories
mw-redirect
Lawrence Livermore Laboratories

values: padding-top:10px; font-size:smaller; line-height:1em; text-align:right;

values: border-collapse:collapse; border-style:none; float:right; margin:0.5em 0.75em; width:33%;

values:
/wiki/DOS_I/O_System
mw-redirect
DOS I/O System

values:
/wiki/Digital_Systems_(Seattle)
mw-redirect
Digital Systems (Seattle)

values:
/wiki/Omron_of_America
mw-redirect
Omron of America

values:
/wiki/Octopus_(network)
mw-redirect
Octopus (network)

values:
/wiki/Bill_Millard
mw-redirect
Bill Millard

values:
/wiki/X86_microprocessor
mw-redirect
X86 microprocessor

values:
/wiki/DMA_controller
mw-redirect
DMA controller

values:
/wiki/Video_display_card
mw-redirect
Video display card

values: This claim needs references to reliable sources. (September 2015)

values:
noprint Inline-Template Template-Fact
white-space:nowrap;

values:
/wiki/MBR_invocation
mw-redirect
MBR invocation

values:
/wiki/VBR_invocation
mw-redirect
VBR invocation

values:
/wiki/Network_adapter
mw-redirect
Network adapter

values:
/wiki/Cassette_BASIC
mw-redirect
Cassette BASIC

values:
/wiki/Cassette_recorder
mw-redirect
Cassette recorder

values: Help:Introduction to referencing with Wiki Markup/1

values: plainlinks metadata ambox ambox-content ambox-Unreferenced

values:
/wiki/Interrupt_vector
mw-redirect
Interrupt vector

values:
/wiki/SCSI_controller
mw-redirect
SCSI controller

values:
/wiki/Network_interface_card
mw-redirect
Network interface card

values:
/wiki/DEBUG_(DOS_Command)
mw-redirect
DEBUG (DOS Command)

values: This claim needs references to reliable sources. (October 2008)

values: This claim needs references to reliable sources. (October 2014)

values:
/wiki/All_points_addressable
mw-redirect
All points addressable

values: Edit section: Processor microcode updates

values:
/wiki/System_Locked_Preinstallation
mw-redirect
System Locked Preinstallation

values: This claim needs references to reliable sources. (February 2015)

values: Advanced Configuration and Power Interface

values: This claim needs references to reliable sources. (March 2013)

values:
/wiki/System_clock
mw-redirect
System clock

values:
/wiki/Plastic_leaded_chip_carrier
mw-redirect
Plastic leaded chip carrier

values:
/wiki/Serial_Peripheral_Interface
mw-redirect
Serial Peripheral Interface

values: background: #ececec; color: #2C2C2C; font-size: smaller; vertical-align: middle; text-align: center;

values:
/wiki/Chernobyl_accident
mw-redirect
Chernobyl accident

values: Edit section: Alternatives and successors

values: plainlinks noexcerpt noprint asof-tag update

values:
/wiki/Extensible_Firmware_Interface
mw-redirect
Extensible Firmware Interface

values:
/wiki/Intel_Itanium_architecture
mw-redirect
Intel Itanium architecture

values:
/wiki/Open_hardware
mw-redirect
Open hardware

values: display:table-cell;padding:0.2em 0.2em 0.2em 0.3em;vertical-align:middle

values: margin:0.5em 0 0.5em 1em;border:solid #aaa 1px

values:
/wiki/Fujitsu_TBIOS
mw-redirect
Fujitsu TBIOS

values:
reflist mw-references-wrap
list-style-type: decimal;

values:
/wiki/Michael_Swaine_(technical_author)
mw-redirect
Michael Swaine (technical author)

values:
nofollow
external text
http://www.ddj.com/184410428

values:
/wiki/Thomas_Fischer_(IMSAI)
mw-redirect
Thomas Fischer (IMSAI)

values:
nofollow
external text
http://www.reenigne.org/crtc/PC-XT.pdf

values: International Standard Book Number (identifier)

values:
/wiki/Smart_Computing
mw-redirect
Smart Computing

values:
nofollow
http://www.intel.com/technology/efi/
external text

values: -moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;

values:
/wiki/IBM_Corporation
mw-redirect
IBM Corporation

values: commons:Category:Basic Input Output System

values: Category:All articles lacking reliable references

values: Category:Articles lacking reliable references from December 2014

values: Category:Webarchive template wayback links

values: Category:CS1 German-language sources (de)

values: Category:All articles with unsourced statements

values: Category:Articles with unsourced statements from September 2015

values: Category:Articles needing additional references from October 2014

values: Category:All articles needing additional references

values: Category:Articles with unsourced statements from October 2008

values: Category:Articles with unsourced statements from October 2014

values: Category:Articles with unsourced statements from February 2015

values: Category:Articles with unsourced statements from March 2013

values: Category:Articles containing potentially dated statements from 2011

values: Category:All articles containing potentially dated statements

values: Category:Articles containing potentially dated statements from 2014

values: Discussion about edits from this IP address [ctrl-alt-n]

values: A list of edits made from this IP address [ctrl-alt-y]

values: You are encouraged to create an account and log in; however, it is not mandatory

values: You're encouraged to log in; however, it's not mandatory. [ctrl-alt-o]

values:
/wiki/BIOS
View the content page [ctrl-alt-c]
c

values: Discussion about the content page [ctrl-alt-t]

values: p-namespaces navigation vectorTabs p-namespaces-label

values:
p-variants
navigation
vectorMenu emptyPortlet
p-variants-label

values:
/w/index.php?title=BIOS&action=edit
Edit this page [ctrl-alt-e]
e

values: Past revisions of this page [ctrl-alt-h]

values: p-views navigation vectorTabs p-views-label

values:
p-cactions
navigation
vectorMenu emptyPortlet
p-cactions-label

values:
mw-wiki-logo
/wiki/Main_Page
Visit the main page

values:
/wiki/Main_Page
Visit the main page [ctrl-alt-z]
z

values: Featured content – the best of Wikipedia

values: Find background information on current events

values:
/wiki/Special:Random
Load a random article [ctrl-alt-x]
x

values: portal navigation p-navigation p-navigation-label

values: Guidance on how to use and edit Wikipedia

values: About the project, what you can do, where to find things

values: A list of recent changes in the wiki [ctrl-alt-r]

values: portal navigation p-interaction p-interaction-label

values: List of all English Wikipedia pages containing links to this page [ctrl-alt-j]

values: Recent changes in pages linked from this page [ctrl-alt-k]

values:
https://af.wikipedia.org/wiki/BIOS
BIOS – Afrikaans
af
af
interlanguage-link-target

values:
https://az.wikipedia.org/wiki/BIOS
BIOS – Azerbaijani
az
az
interlanguage-link-target

values:
https://be.wikipedia.org/wiki/BIOS
BIOS – Belarusian
be
be
interlanguage-link-target

values: BIOS – Belarusian (Taraškievica orthography)

values:
https://bg.wikipedia.org/wiki/BIOS
BIOS – Bulgarian
bg
bg
interlanguage-link-target

values:
https://bs.wikipedia.org/wiki/BIOS
BIOS – Bosnian
bs
bs
interlanguage-link-target

values:
https://br.wikipedia.org/wiki/BIOS
BIOS – Breton
br
br
interlanguage-link-target

values:
https://ca.wikipedia.org/wiki/BIOS
BIOS – Catalan
ca
ca
interlanguage-link-target

values:
https://cs.wikipedia.org/wiki/BIOS
BIOS – Czech
cs
cs
interlanguage-link-target

values:
https://da.wikipedia.org/wiki/BIOS
BIOS – Danish
da
da
interlanguage-link-target

values:
https://de.wikipedia.org/wiki/BIOS
BIOS – German
de
de
interlanguage-link-target

values:
https://el.wikipedia.org/wiki/BIOS
BIOS – Greek
el
el
interlanguage-link-target

values:
https://es.wikipedia.org/wiki/BIOS
BIOS – Spanish
es
es
interlanguage-link-target

values:
https://eo.wikipedia.org/wiki/BIOS
BIOS – Esperanto
eo
eo
interlanguage-link-target

values:
https://eu.wikipedia.org/wiki/BIOS
BIOS – Basque
eu
eu
interlanguage-link-target

values:
https://gl.wikipedia.org/wiki/BIOS
BIOS – Galician
gl
gl
interlanguage-link-target

values: बायोस – Hindi

values:
https://hr.wikipedia.org/wiki/BIOS
BIOS – Croatian
hr
hr
interlanguage-link-target

values:
https://id.wikipedia.org/wiki/BIOS
BIOS – Indonesian
id
id
interlanguage-link-target

values:
https://it.wikipedia.org/wiki/BIOS
BIOS – Italian
it
it
interlanguage-link-target

values:
https://he.wikipedia.org/wiki/BIOS
BIOS – Hebrew
he
he
interlanguage-link-target

values:
https://ka.wikipedia.org/wiki/BIOS
BIOS – Georgian
ka
ka
interlanguage-link-target

values: Базалық енгізу-шығару жүйесі – Kazakh

values:
https://ku.wikipedia.org/wiki/BIOS
BIOS – Kurdish
ku
ku
interlanguage-link-target

values:
https://lv.wikipedia.org/wiki/BIOS
BIOS – Latvian
lv
lv
interlanguage-link-target

values:
https://lb.wikipedia.org/wiki/BIOS
BIOS – Luxembourgish
lb
lb
interlanguage-link-target

values:
https://lt.wikipedia.org/wiki/BIOS
BIOS – Lithuanian
lt
lt
interlanguage-link-target

values:
https://lmo.wikipedia.org/wiki/BIOS
BIOS – Lombard
lmo
lmo
interlanguage-link-target

values:
https://hu.wikipedia.org/wiki/BIOS
BIOS – Hungarian
hu
hu
interlanguage-link-target

values:
https://ms.wikipedia.org/wiki/BIOS
BIOS – Malay
ms
ms
interlanguage-link-target

values:
https://nl.wikipedia.org/wiki/BIOS
BIOS – Dutch
nl
nl
interlanguage-link-target

values:
https://no.wikipedia.org/wiki/BIOS
BIOS – Norwegian
no
no
interlanguage-link-target

values:
https://nn.wikipedia.org/wiki/BIOS
BIOS – Norwegian Nynorsk
nn
nn
interlanguage-link-target

values:
https://uz.wikipedia.org/wiki/BIOS
BIOS – Uzbek
uz
uz
interlanguage-link-target

values:
https://pl.wikipedia.org/wiki/BIOS
BIOS – Polish
pl
pl
interlanguage-link-target

values:
https://pt.wikipedia.org/wiki/BIOS
BIOS – Portuguese
pt
pt
interlanguage-link-target

values:
https://ro.wikipedia.org/wiki/BIOS
BIOS – Romanian
ro
ro
interlanguage-link-target

values:
https://ru.wikipedia.org/wiki/BIOS
BIOS – Russian
ru
ru
interlanguage-link-target

values:
https://sco.wikipedia.org/wiki/BIOS
BIOS – Scots
sco
sco
interlanguage-link-target

values:
https://sq.wikipedia.org/wiki/BIOS
BIOS – Albanian
sq
sq
interlanguage-link-target

values:
https://simple.wikipedia.org/wiki/BIOS
BIOS – Simple English
simple
simple
interlanguage-link-target

values:
https://sl.wikipedia.org/wiki/BIOS
BIOS – Slovenian
sl
sl
interlanguage-link-target

values:
https://sr.wikipedia.org/wiki/BIOS
BIOS – Serbian
sr
sr
interlanguage-link-target

values:
https://sh.wikipedia.org/wiki/BIOS
BIOS – Serbo-Croatian
sh
sh
interlanguage-link-target

values:
https://fi.wikipedia.org/wiki/BIOS
BIOS – Finnish
fi
fi
interlanguage-link-target

values:
https://tl.wikipedia.org/wiki/BIOS
BIOS – Tagalog
tl
tl
interlanguage-link-target

values: பயாஸ் – Tamil

values: బయోస్ – Telugu

values: ไบออส – Thai

values:
https://tr.wikipedia.org/wiki/BIOS
BIOS – Turkish
tr
tr
interlanguage-link-target

values:
https://uk.wikipedia.org/wiki/BIOS
BIOS – Ukrainian
uk
uk
interlanguage-link-target

values:
https://vi.wikipedia.org/wiki/BIOS
BIOS – Vietnamese
vi
vi
interlanguage-link-target

values:
https://zh.wikipedia.org/wiki/BIOS
BIOS – Chinese
zh
zh
interlanguage-link-target

values: mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-BIOS rootpage-BIOS skin-vector action-view


text:
Alcohol laws of Australia
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Alcohol laws of Australia regulate the sale and consumption of alcoholic beverages (If you are 18 and over in Australia you are allowed to vote, drink and drive). Legal age of drinking is 18.
Contents
[hide]
1 Alcohol drinking age
2 Alcohol laws by state
2.1 South Australia
2.2 Victoria
2.3 New South Wales
2.4 Western Australia
2.5 Australian Capital Territory
3 See also
4 References
Alcohol drinking age[edit]
State
Current legal
drinking age
Year adopted
Previous legal drinking age
New South Wales
18 1905[1] 21
Queensland
18 1974[1] 21
South Australia
18 1971[1] 21 to 20 in 1968
Tasmania
18 1974[1] 21 to 20 in 1967
Victoria
18 1906[1] 10
Western Australia
18 1970[1] 21
Australian Capital Territory
18 1928[1] Not amended
Northern Territory
18 1929[1] Not amended
Alcohol laws by state[edit]
All tourists' legal proof of age is foreign passports only, and not any 18+ card (especially in New Zealand, where it serves the same purpose as state-specific 18+ cards for residents of each respective state if they don't already have a driving licence.)
South Australia[edit]
In South Australia, the major legislation which controls the sale and consumption of alcohol is the Liquor Licensing Act 1997 (SA). The principal aim of the Act is to minimise the harm associated with the consumption of alcohol in the community of South Australia. The drinking age was lowered from 21 to 20 in 1968 and by 1971 South Australia had a drinking age of 18.[2][3] Between 1836 and 1839, liquor licences were granted by the Governor.
On 21 February 1839, Act No. 1 of 1839 became the first liquor licensing legislation in the Province, including three licenses:
General Publican's Licence
Wine, Ale, Beer and other Malt Liquors Licence
Storekeeper's Licence
In 1869, a Storekeeper's Colonial Wine Licence was introduced.[4]
Victoria[edit]
Alcohol may not be sold in Victoria without a licence or permit being obtained from the State government. Licences and permits are issued by the Victorian Commission for Gambling and Liquor Regulation,[5] under the Liquor Control Reform Act 1998.[6]
In Victoria, alcohol may not be sold to a person who is under 18 years of age unless accompanied by a guardian (or spouse) and for consumption during a meal,[7] and minors must not be on licensed premises (i.e. premises on which alcohol may be sold or consumed) unless accompanied by an adult or other limited circumstances.[8]
There are several categories of licences available.[9] The most common are:
packaged liquor licence, which permit the sale of liquor to customers to take away from retail liquor stores and supermarkets.
general licence, which permit the sale of liquor to customers for drinking on the premises, and to take away. These are used by pubs, hotels and taverns.
BYO permit, which allow customers to bring their own liquor and drink it on the premises. These are obtained by restaurants and clubs that do not intend to hold a liquor licence.
Other specialised licences are: full club licence, renewable limited club licence, temporary limited licence, renewable limited licence, restricted club licence, pre-retail licence (for wholesalers, producers, brewers and liquor importers), and vigneron’s licence.
Until May 2015, there were several areas in Melbourne which had the status of "dry-areas", where a vote was required before a liquor licence was granted within the area. This requirement has now ceased.[10] Some local government councils have passed by-laws prohibiting the consumption of alcohol on designated streets, parks and other areas within their jurisdictions.[11]
In Victoria, if a minor is caught with alcohol in public it can be confiscated and guardians notified of the offence, and a fine may be imposed.[12]
Previously, minors were allowed to drink alcohol if it is given to them by anyone on private property, for example a party. New laws which came into effect late 2011, require parental permission to be given to any adult serving alcohol to minors, under a penalty of $7,000.[13]
In Victoria, fully licensed drivers of motor vehicles must have a Blood alcohol content (BAC) below 0.05%. Learner and probationary licensed drivers must not consume any alcohol before driving (i.e. the BAC must be zero).
Victorian alcohol laws only allow the following identification as legally accepted proof-of-age in licensed premises:
Current Australian driver licence
Current Victorian learner driver permit card
Current passport (Australian or foreign)
Current Keypass identity card.
Current proof-of-age card from any Australian state or territory.[14]
New South Wales[edit]
Alcohol may not be sold in NSW without a licence or permit being obtained from the State government.[15]
In NSW, alcohol may not be sold to a person who is under 18 years of age unless accompanied by a guardian (or spouse) and for consumption during a meal, and minors must not be on licensed premises (i.e. premises on which alcohol may be sold or consumed) unless accompanied by an adult or other limited circumstances.[16] The designation of restricted area (18+ only) and supervised area (minors must be accompanied by adults) must be displayed on the door or window facing outwards.
There are several categories of licences available. The most common are:[15]
packaged liquor licence, which permit the sale of liquor to customers to take away from retail liquor stores and supermarkets. They must close at 11pm at the latest.
general licence, which permit the sale of liquor to customers for drinking on the premises, and to take away. These are used by pubs, hotels and taverns.
BYO permit, which allow customers to bring their own liquor and drink it on the premises. These are obtained by restaurants and clubs that do not intend to hold a liquor licence, or do not sell and supply liquor themselves.
Other specialised licences are: full club licence, renewable limited club licence, temporary limited licence, renewable limited licence, restricted club licence, pre-retail licence (for wholesalers, producers, brewers and liquor importers), and vigneron’s licence.
Some local government councils have passed by-laws prohibiting the consumption of alcohol on streets within their areas, especially the Sydney CBD Entertainment Precinct, which stretches from the Sydney Harbour Bridge, Circular Quay down to the end of George Street. On other parts of Sydney, many streets still have similar 'alcohol-free streets', notably the immediate streets near railway stations, all main roads in Hurstville, Bankstown, Chatswood and City of Willoughby. Most of these bans last for 4 years which can be renewed each September of the 4-year cycle under council discretion.
In a designated area within the Sydney CBD, there is a 1:30 am lockout meaning no patrons can enter bars after that point, and no existing patrons can re-enter after that time, while last drinks are at 3am. There are restrictions on what can be served after midnight. For example, liquor cannot be served "neat".[17]
In NSW, if a minor is caught with alcohol in public it can be confiscated and guardians notified of the offence, and a fine may occur.
New South Wales alcohol laws only allow the following identification as legally accepted proof-of-age in licensed premises:
Current Australian driver licence
Current Victorian learner driver permit card
Current passport (Australian or foreign)
Current NSW proof-of-age card (if they don't already have a driver's licence).
Western Australia[edit]
State legislation governs the sale and supply of alcohol in Western Australia. The Liquor Control Act 1988 and the Liquor Control Regulations 1989 is administered by the Department of Racing, Gaming and Liquor. The purpose of the Liquor Act is primarily to regulate the sale, supply, and consumption of alcohol. Before 1970, Western Australia drinking age was 21. It is illegal for any person under the age of 18 years to purchase, supply, or drink alcohol on licensed or regulated premises, even if they are with their parents or guardian. The maximum penalty for a minor to consume alcohol on licensed premises is a $2,000AUD fine. It is an offence in Western Australia for persons of any age to drink in public, such as on the street, park, or beach without first having obtained a permit from the appropriate local government authority. Such permits are at the discretion of the local council - some public events have a total ban on alcohol consumption and no permits will be issued.
Western Australian alcohol laws only allow the following identification as legally accepted proof-of-age in licensed premises:[3][18][19]
Current Western Australian driver licence or a driver licence issued by an Australian state or territory government
Current Western Australian learner driver permit card
Current passport (Australian or foreign)
Current Western Australian Photo Card, issued by the Department of Transport or a proof-of-age card issued by an Australian state or territory government
Australian Capital Territory[edit]
Alcohol was originally banned in Canberra; see King O'Malley. Alcohol was made legal again following a plebiscite in 1928.[20][21]
See also[edit]
Alcohol in Australia
Driver's licence in Australia
References[edit]
^ Jump up to: a b c d e f g h "Underage Drinking: develop policy options to reverse the present trend facing Australia" (PDF). Retrieved 4 February 2014.
Jump up ^ "Archived copy". Archived from the original on 17 February 2011. Retrieved 2011-02-28.
^ Jump up to: a b "Archived copy" (PDF). Archived from the original (PDF) on 10 March 2011. Retrieved 2011-02-27.
Jump up ^ "History of Liquor Licensing in South Australia". Olgc.sa.gov.au. Retrieved 2010-07-22.
Jump up ^ [1]
Jump up ^ "LIQUOR CONTROL REFORM ACT 1998". Austlii.edu.au. 2010-04-01. Retrieved 2010-07-22.
Jump up ^ "Liquor Control Reform Act 1998, sec 119". Austlii.edu.au. Retrieved 2010-07-22.
Jump up ^ "Liquor Control Reform Act 1998, sec 120". Austlii.edu.au. Retrieved 2010-07-22.
Jump up ^ [2] Archived 10 July 2009 at the Wayback Machine.
Jump up ^ The Age, 13 May 2015: End to dry polls for Melbourne cafes and restaurants
Jump up ^ City of Melbourne: Consumption of alcohol
Jump up ^ "Page Not Found" (PDF).
Jump up ^ "Teen Drinking Law - The Law".
Jump up ^ Victorian Commission for Gambling and Liquor Regulation Proof of Age
^ Jump up to: a b "New alcohol laws now in place".
Jump up ^ Liquor Act 2007 (NSW) s 117. AustLII
Jump up ^ The boomer supremacy
Jump up ^ http://www.alcoholthinkagain.com.au/Alcohol%20Related%20Information/The%20Law.aspx
Jump up ^ "Liquor Act 2007". Austlii.edu.au. Retrieved 2013-10-13.
Jump up ^ "History of the Capital".
Jump up ^ Ian Warden. "Ditty details end of drink drought". Canberra Times.
[hide]
v
t
e
Alcohol-related topics by country
Countries
Afghanistan
Australia
Indonesia
Iran
Malaysia
New Zealand
Sudan
Cultures
Australia
Korea
Types
Canada
Chinese
Sweden
Laws
Australia
Canada
Iceland
India
Prohibition
Germany
Russia
Consumption
United Kingdom
United States
Youth consumption
Commons
Category
Retrieved from "https://en.wikipedia.org/w/index.php?title=Alcohol_laws_of_Australia&oldid=815910703"
Categories:
Alcohol law in Australia
Alcohol law by country
Hidden categories:
Webarchive template wayback links
Use Australian English from September 2014
All Wikipedia articles written in Australian English
Use dmy dates from July 2011
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Article
Talk
Variants
Views
Read
Edit
View history
More
Search
Navigation
Main page
Contents
Featured content
Current events
Random article
Donate to Wikipedia
Wikipedia store
Interaction
Help
About Wikipedia
Community portal
Recent changes
Contact page
Tools
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Wikidata item
Cite this page
Print/export
Create a book
Download as PDF
Printable version
Languages
Add links
This page was last edited on 18 December 2017, at 00:33.
Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Privacy policy
About Wikipedia
Disclaimers
Contact Wikipedia
Developers
Cookie statement
Mobile view
Enable previews

key: html

type: local

value: div

attrs: id class

values: mw-page-base noprint

values: mw-head-base noprint

value: a

attrs: id class lang

values: firstHeading firstHeading en

values: siteSub noprint

values: jump-to-nav mw-jump

attrs: href title

attrs: href class title

values:
/wiki/Alcoholic_beverages
mw-redirect
Alcoholic beverages

value: p

attrs: role tabindex class

values: button 0 togglelink

value: span

value: li

values: Edit section: Australian Capital Territory

values:
/wiki/Driver%27s_licence_in_Australia
mw-redirect
Driver's licence in Australia

values:
nofollow
external text
http://www.nsw.gov.au/newlaws

values: -moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;

attrs: alt src width height srcset data-file-width data-file-height

values:
navbox-image
4
width:1px;padding:0px 0px 0px 2px

values:
/wiki/Drinking_culture_in_Australia
mw-redirect
Drinking culture in Australia

values: Prohibition in the Russian Empire and the Soviet Union

values: Alcohol licensing laws of the United Kingdom

values:
/wiki/Alcohol_laws_of_the_United_States
mw-redirect
Alcohol laws of the United States

values: Alcohol consumption by youth in the United States

attrs: alt src title width height srcset data-file-width data-file-height

values: nowraplinks hlist collapsible autocollapse navbox-inner

values: Category:Webarchive template wayback links

values: Category:Use Australian English from September 2014

values: Category:All Wikipedia articles written in Australian English

values: Discussion about edits from this IP address [ctrl-alt-n]

values: A list of edits made from this IP address [ctrl-alt-y]

values: You are encouraged to create an account and log in; however, it is not mandatory

values: You're encouraged to log in; however, it's not mandatory. [ctrl-alt-o]

values:
/wiki/Alcohol_laws_of_Australia
View the content page [ctrl-alt-c]
c

values: Discussion about the content page [ctrl-alt-t]

values: p-namespaces navigation vectorTabs p-namespaces-label

values:
p-variants
navigation
vectorMenu emptyPortlet
p-variants-label

values: Past revisions of this page [ctrl-alt-h]

values: p-views navigation vectorTabs p-views-label

values:
p-cactions
navigation
vectorMenu emptyPortlet
p-cactions-label

values:
mw-wiki-logo
/wiki/Main_Page
Visit the main page

values:
/wiki/Main_Page
Visit the main page [ctrl-alt-z]
z

values: Featured content – the best of Wikipedia

values: Find background information on current events

values:
/wiki/Special:Random
Load a random article [ctrl-alt-x]
x

values: portal navigation p-navigation p-navigation-label

values: Guidance on how to use and edit Wikipedia

values: About the project, what you can do, where to find things

values: A list of recent changes in the wiki [ctrl-alt-r]

values: portal navigation p-interaction p-interaction-label

values: List of all English Wikipedia pages containing links to this page [ctrl-alt-j]

values: Recent changes in pages linked from this page [ctrl-alt-k]

values:
/wiki/Wikipedia:File_Upload_Wizard
Upload files [ctrl-alt-u]
u

values: A list of all special pages [ctrl-alt-q]

values: Permanent link to this revision of the page

values: Link to connected data repository item [ctrl-alt-g]

values: Printable version of this page [ctrl-alt-p]

values:
uls-settings-trigger
Language settings
0
button
true

values: /static/images/wikimedia-button-1.5x.png 1.5x, /static/images/wikimedia-button-2x.png 2x

values: /static/images/poweredby_mediawiki_132x47.png 1.5x, /static/images/poweredby_mediawiki_176x62.png 2x

values:
suggestions
display: none; font-size: 13px;

values: mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-Alcohol_laws_of_Australia rootpage-Alcohol_laws_of_Australia skin-vector action-view