BIOS - Wikipedia

The original IBM PC BIOS and cassette BASIC was stored on mask-programmed read-only memory ROM chips in sockets on the motherboard. 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. MSI and Gigabyte Technology have followed suit with the MSI K9ND MS-9282 and MSI K9SD MS-9185 resp. SS:SP points to a valid stack that is presumably large enough to support hardware interrupts, but otherwise SS and SP are undefined. It was able to erase flash ROM Настройка setup bios award content. Early BIOS versions did not have passwords or boot-device selection options. Unified Extensible Firmware Interface UEFI was designed as a successor to BIOS, aiming to address its technical shortcomings. The behavior if the BIOS does not find a bootable device has varied as personal computers developed. At the same time, since 2010 BIOS technology is in a transitional process toward the UEFI. Some video cards have extension ROMs that replace the video services of the motherboard BIOS with their own video services. 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. The BIOS selects candidate boot devices using information collected by POST and configuration information from EEPROM, CMOS RAM or, in the earliest PCs, DIP настройка setup bios award. 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. 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. 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. 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 longbefore accepting a boot sector and considering the device bootable. The boot program must set up its own stack or at least MS-DOS 6 acts like it mustbecause the настройка setup bios award 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. Retrieved 2 February 2013. This code verifies if the rest of the BIOS is intact using hash checksums or other methods before transferring control to it.

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BIOS - Wikipedia

Features present in the BIOS setup utility typically include:In modern PCs the BIOS is stored in rewritable memory, allowing the contents to be replaced and modified. For similar programs on non-PC systems, see booting. 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. Heise 5 : 240. 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. Volume 7, Issue 4. In 2006, the first systems supporting a Serial Peripheral Interface SPI appeared, and the BIOS flash memory moved again. Usually the key is advertised for short time during the early startup, for example "Press F1 to enter CMOS setup". For the general concept, see firmware. 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. Replacing the Motherboard Battery. If the system has just been настройка setup bios award up or the reset button was pressed "cold boot"the full power-on self-test POST is run. Major BIOS vendors include American Megatrends AMIInsyde Software, Phoenix Technologies and Byosoft. 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. Early BIOS versions did not have passwords or boot-device selection options. BIOS services are настройка setup bios award 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. So CPM on the IMSAI was a joint effort between Glenn and Gary. Error codes or messages were displayed on the screen, or coded series of sounds were generated to signal настройка setup bios award when the power-on self-test POST had not proceeded to the point of successfully initializing a video display adapter. 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 настройка setup bios award 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. Overclocking may, however, seriously compromise system reliability in insufficiently cooled computers and generally shorten component lifespan. 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. 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. 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. 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. As of at least 2015, Apple has removed legacy BIOS support from MacBook Pro computers. 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 настройка setup bios award scanned.

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настройка setup bios award

Volume 8, Issue 6. 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. So CPM on the IMSAI was a joint effort between Glenn and Gary. MSI and Gigabyte Technology have followed suit with the MSI K9ND MS-9282 and MSI K9SD MS-9185 resp. Starting in 1997, the BIOS flash moved to the LPC bus, a functional replacement for ISA, following a new standard implementation настройка setup bios award as "firmware hub" FWH. 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. In the AT, the keyboard interface was controlled by a microcontroller with its own programmable memory. To increase the speed of screen output, many programs bypassed the BIOS and programmed the video display hardware directly. The IBM PCjr is unique among PCs in having two ROM cartridge slots on the front. The first one found in the wild was Mebromi, targeting Chinese users. 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, настройка setup bios award some other interrupts, including ones that BIOS generates for programs to hook, have been set to a default dummy ISR that immediately returns. Unified Extensible Firmware Interface UEFI was designed as a successor to BIOS, aiming to address its technical shortcomings. Features present in the BIOS setup utility typically include:In modern PCs the BIOS is stored in rewritable memory, allowing the contents to be replaced and modified. Volume 7, Issue 4. 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. The boot program must set up its own stack or at least MS-DOS 6 acts like it mustbecause 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. The original IBM PC and XT had Microsoft Cassette BASIC in ROM, настройка setup bios award if no bootable device was found, ROM BASIC was started by calling INT 18h. 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. 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 настройка setup bios award, for loading and saving BASIC programs to tape. With the El Torito optical media boot standard, the optical drive actually emulates a 3. 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. 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. 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.

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Other BIOS simulations and additional help with the computer BIOS can be found on our BIOS help page. Phoenix - Award BIOS differences. Arrow keys used to navigate.

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. All memory at and above address 0x00500 can be used by the boot program; it may even overwrite itself. Archived from the original on 2011-09-25. 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. Options on the IBM PC and XT were set by switches and jumpers on the main board and on peripheral cards. 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. With настройка setup bios award El Torito optical media boot настройка setup bios award, the optical drive actually emulates a 3. 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. 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. The actual key depends on specific hardware. 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. 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. 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. In modern personal computers running modern operating systems the BIOS is used only during booting and initial loading of настройка setup bios award software. Versions of MS-DOS, PC DOS or DR-DOS contain a file called variously "IO. The proof-of-concept does not настройка setup bios award a flaw in the BIOS implementation, but only involves the normal BIOS flashing procedures. It had a century bit which allowed for manually changing the century when the year 2000 happened. 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. For example, a SCSI controller usually has a BIOS extension ROM that adds support for hard drives connected through that controller. 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. Unified Extensible Firmware Interface UEFI was designed as a successor to BIOS, aiming to address its technical shortcomings. 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.