SeaBIOS
 | This article needs additional citations for verification. (February 2014) |
 SeaBIOS is the default BIOS for QEMU | |
| Developer(s) | Kevin O'Connor |
|---|---|
| Initial release | February 25, 2008 |
| Stable release | 1.14.0[1]
/ 10 August 2020 |
| Repository | |
| Written in | C |
| Platform | x86 |
| Size | 463 kB |
| Available in | English |
| Type | BIOS |
| License | LGPLv3 |
| Website | www |
SeaBIOS is an open-source implementation of a 16-bit x86 BIOS, serving as a freely available firmware for x86 systems. Aiming for compatibility, it supports standard BIOS features and calling interfaces that are implemented by a typical proprietary x86 BIOS. SeaBIOS can either run on bare hardware as a coreboot payload, or can be used directly in emulators such as QEMU and Bochs.
Initially, SeaBIOS was based on the open-source BIOS implementation included with the Bochs emulator. The project was created with intentions to allow native usage on x86 hardware, and to be based on an improved and more easily extendable internal source code implementation.[2]: 3–5
Features
Features supported by SeaBIOS include the following:
- Graphical bootsplash screen (JPEG and BMP)
- USB keyboard and mouse support
- USB Mass Storage boot support
- USB Attached SCSI boot support
- ATA support
- AHCI support
- NVMe support
- El Torito optical disc drive boot support
- BIOS Boot Specification (BBS)
- Rebooting on Control-Alt-Delete key press
- Network booting support e.g. iPXE or gPXE
- Logical block addressing (LBA)
- POST Memory Manager (PMM)
- Paravirtualization, Xen HVM, VirtIO
- Coreboot Payloads (LZMA compressed)
- PCI Firmware Specification
- SeaBIOS as a Compatibility Support Module (CSM) for Unified Extensible Firmware Interface (UEFI) and Open Virtual Machine Firmware (OVMF)
- Virtual machine host notification of paravirtualized guests which panic via the pvpanic driver
- A patch exists to load the SLIC table from a licensed OEM Windows BIOS.[3]
- Trusted Platform Module
- Enhanced Disk Drive (EDD) (INT 13H extensions)
- e820 memory map
- Protected mode interfaces, e.g. APM, Legacy PnP, DMI, PCI BIOS, MPS, SMBIOS, VBE, and ACPI
- System Management Mode
- Does not support ESCD
SeaBIOS's boot device selection menu can be accessed by pressing Esc during the boot process.
Uses
SeaBIOS can run natively on x86 hardware, in which case it is loaded by coreboot as a payload; it runs on 386 and later processors, and requires a minimum of 1 MB of RAM. Compiled SeaBIOS images can be flashed into supported motherboards using flashrom.[4] SeaBIOS also runs inside an emulator; it is the default BIOS for the QEMU and KVM virtualization environments, and can be used with the Bochs emulator. It is also included in some Chromebooks, although it is not used by the Chrome OS.[5]
Development
Most of the SeaBIOS source code is written in C, with its build system relying on the standard GNU toolchain.[2]: 5–7 SeaBIOS has been tested with various bootloaders and operating systems, including GNU GRUB, LILO, SYSLINUX, Microsoft Windows, Linux, FreeDOS, FreeBSD, NetBSD and OpenBSD.
See also
References
- ^ "SeaBIOS Releases". seabios.org. 2019-12-09. Retrieved 2019-12-30.
- ^ a b Kevin O'Connor (November 11, 2010). "SeaBIOS in a virtualized environment" (PDF). linuxplumbersconf.org. Retrieved December 12, 2014.
- ^ "ghuntley/seaslic GitHub". Github.com. Retrieved 2014-02-25.
- ^ "SeaBIOS - coreboot". Retrieved 2015-01-22.
- ^ "3 alternatives to Chrome OS on Google's Chromebook Pixel — Tech News and Analysis". Gigaom.com. 2013-02-26. Retrieved 2014-02-25.
External links
- Official website
- Find your way through the x86 firmware maze – covers the SeaBIOS boot sequence and memory maps