110 likes | 224 Views
UEFI 与固件程序设计. Tel : 69589584 Email:wang.box@163.com. 同济大学软件学院. What’s the UEFI?. UEFI ( U nified E xtensible F irmware I nterface) 是由 英特尔 公司联合业界共同提出的一种欲在未来电脑系统中替代传统 BIOS (Legacy BIOS) 的升级解决方案。 . Another question, What’s the BIOS?. 继续. 返回. What’s the BIOS?.
E N D
UEFI与固件程序设计 Tel:69589584 Email:wang.box@163.com 同济大学软件学院
What’s the UEFI? UEFI (Unified Extensible Firmware Interface)是由英特尔公司联合业界共同提出的一种欲在未来电脑系统中替代传统BIOS (Legacy BIOS)的升级解决方案。 Another question, What’s the BIOS? 继续 返回
What’s the BIOS? BIOS (Basic Input and Output System)基本输入输出系统,它是一组固化到计算机内主板上一个ROM芯片上的程序,它保存着计算机最重要的开机上电自检、硬件初始化程序和系统底层的服务程序等。 Push Power Button CPU Reset Found MBR 硬件逻辑 BIOS OS RTC 继续 返回
Agenda • BIOS background • History • Functions • Legacy BIOS’s Flaws • Change 继续 返回
BIOS background -- History • Before firmware— Switchs on a piece of plywood • BIOS--for original IBM PC/XT and PC/AT in 1980s • EFI-- Spring 2000 IDF (Intel Developer’s Forum) -- EFI 1.10 specification • UEFI–Originated from the EFI 1.10 specification --Updated and managed by the Unified EFI Forum 继续 返回
BIOS background -- Functions • Based on 8086 architecture • POST—Power On Self Test • A group of clearly defined OS-independent interface for hardware • Int10 for Video service • Int13 disk service • Int16 keyboard service • Int18 BIOS ROM loader • Int19 bootstrap loader • Availability of MS-DOS outside of IBM allowed applications to run equally well across different brands of box "PC clones". 继续 返回
BIOS background -- LegacyBIOS’s Flaws • It is not platform independent, it highly depends on Intel 8086 Software Interrupt model • Real mode • 16-bits register access • No memory address beyond 1MB • Option ROM space limited to below 1MB • Modern Intel CPU architecture has come to 32bits, 64bits protection mode, with HT and Multi-core, but for compatibility, it should still boot up in 16 bit real mode 继续 返回
BIOS background – Flaws (cont.) • It is inaccessible to boot 64bits system which still call into 16 bit legacy firmware when Itanium processor family come into life. • More and more new technology come out, like VT, LT etc. It is very hard to enable those technology in the whole eco-system quickly in legacy BIOS • Architecture independent is the key for the next generation BIOS, that is where the EFI come from, single driver can work in x86, Itanium and XScale etc. 继续 返回
BIOS background – Flaws (cont.) Code Issue Real Mode Scalability Assembler Complexity Spaghetti Maintenance Spec None! Compatibility OS Loader Slows innovation Tied to HW and BIOS Carries legacy 继续 返回
Compatibility BIOS background – Change • Unified Extensible Firmware Interface • UEFI is an interface specification --download from www.uefi.org • Abstracts the platform from OS • Includes a modular driver model and CPU-independent option ROMs • Compatible by design • Modular and extensible • Complements existing interfaces OS Loader UEFI Firmware Hardware Flexible to meet existing and future needs 继续 返回
High level language protected mode code Scaleable and easy to maintain Straight-forward implementation Clearly defined Innovation Legacy migration Abstraction BIOS background – Change Code Issue Real Mode Scaleability Assembler Complexity Spaghetti Maintenance Spec None! Compatibility OS Loader Slows innovation Tied to HW and BIOS Carries legacy 继续 返回