发信人: wenbobo()
整理人: wenbobo(2003-01-09 10:08:30), 站内信件
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下面是摘自于HELPPC2.1中的有关机器启动过程的信息
wenbobo翻译<[email protected]>
POST - Cold Boot / Power On Self Test Activities
POST - 冷启动、开机自检
- power supply starts Clock Generator (8284) with Power
通电后8284时序发生器开始工作
Good signal on BUS
总线产生正常信号
- CPU reset line is pulsed resetting CPU
CPU的复位引脚被触发，CPU复位
- DS, ES, and SS are cleared to zero
DS，ES，SS初始值为0（CPU处于实模式下）
Cold and Warm Boot both execute the following sequence
冷启动和热启动都会执行一下序列
- CS:IP are set to FFFF:0000 (address of ROM POST code)
CS:IP初始值为FFFF:0000（该地址为BIOS的ROM POST代码）
- jump to CS:IP (execute POST, Power On Self test)
CPU工作，开始取第一条指令（执行POST，开机自检）
- interrupts are disabled
关中断
- CPU flags are set, read/write/read test of CPU registers
设置CPU标志位，用读、写、读来测试CPU寄存器
- checksum test of ROM BIOS
检测ROM BIOS的校验和
- Initialize DMA (verify/init 8237 timer, begin DMA RAM refresh)
初始化DMA（校验、初始化 8237时钟控制器，开始DMA 内存刷新）
- save reset flag then read/write test the first 32K of memory
保存复位标志，然后对内存的前32K字节进行读写测试
- Initialize the Programmable Interrupt Controller (8259)
and set 8 major BIOS ~interrupt~ vectors (interrupts 10h-17h)
初始化8259可编程中断控制器，设置好8个主要的BIOS中断向量(INT 10h-17H)
- determine and set configuration information
检测并设置好CMOS配置信息
- initialize/test CRT controller & test video memory (unless 1234h
found in reset word)
初始化/测试CRT控制器，测试显存（除非在复位字的位置找到1234h）
- test ~8259~ Programmable Interrupt Controller
测试8259可编程中断控制器
- test Programmable Interrupt Timer (~8253~)
测试8253可编程时钟中断控制器
- reset/enable keyboard, verify scan code (AAh), clear keyboard,
check for stuck keys, setup interrupt vector lookup table
复位、激活键盘，校验扫描码，清除键盘缓冲区，检查是否有卡住的键，设置中断查找表
- hardware interrupt vectors are set
设置硬件中断向量
- test for expansion box, test additional RAM
测试扩展设备，测试扩充内存
- read/write memory above 32K (unless 1234h found in reset word)
读写测试32K字节以上的内存（除非在复位字的位置找到1234h）
- addresses C800:0 through F400:0 are scanned in 2Kb blocks in
search of valid ROM. If found, a far call to byte 3 of the ROM
is executed.
以2K字节大小的块为单位，从c800:0到f400:0扫描，查找有效映射的ROM。找到后，对ROM的第3个字节进行远程调用。
- test ROM cassette BASIC (checksum test)
检测ROM BASIC（校验和测试，现在的BIOS已取消ROM BASIC了……）
- test for installed diskette drives & ~FDC~ recalibration & seek
检测安装了的硬盘驱动器、软盘控制器。
- test printer and RS-232 ports. store printer port addresses
at 400h and RS-232 port addresses at 408h. store printer
time-out values at 478h and Serial time-out values at 47Ch.
检测打印机口和RS-232串口。把打印口地址保存在内存的400h，串口地址保存在408h。打印机超时值保存在478h，串口超时值保存在47Ch。
- NMI interrupts are enabled
激活NMI中断
- perform ~INT 19~ (bootstrap loader), pass control to boot record
or cassette BASIC if no bootable disk found
执行INT 19h（引导装载程序），把控制权转交给引导程序
- ~WARM BOOT~ procedure is now executed
现在热启动已经执行完毕了
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