X86内核启动分析五 保护模式小荷尖尖角

时间:2022-09-01 08:04:05

第一次进入保护模式,解压缩内核

startup_32: //head.S (c:\linux\linux-2.6.23\arch\i386\boot\compressed)
=>//Do the decompression, and jump to the new kernel..
=> Jump to the decompressed kernel.

跳转到解压缩内核之后,使能页模式

里面有一个重要的宏定义:
[linux-2.6.23]$ cat .config | grep CONFIG_PAGE_OFFSET
CONFIG_PAGE_OFFSET=0xC0000000
[linux-2.6.23]$

ENTRY(startup_32) //head.S (c:\linux\linux-2.6.23\arch\i386\kernel)
=>Copy bootup parameters out of the way. //主要是boot_params
=>// Initialize page tables
=>//Enable paging
=>call setup_idt
=>je is386
=>jmp start_kernel