修改bootsect.s文件

修改第98行，此处的数值就是信息的字符个数加上3个换行与3个空格： ```c msg1: .byte 13,10 !2个字符 .ascii "Hello midnight,Loading system ..." !33个字符 .byte 13,10,13,10 !4个字符 ``` 每次修改完成后，在linux-0.11目录下执行 **make boot Image** 命令, 修改后的setup.s文件 ```c ! ! setup.s (C) 1991 Linus Torvalds ! ! setup.s is responsible for getting the system data from the BIOS, ! and putting them into the appropriate places in system memory. ! both setup.s and system has been loaded by the bootblock. ! ! This code asks the bios for memory/disk/other parameters, and ! puts them in a "safe" place: 0x90000-0x901FF, ie where the ! boot-block used to be. It is then up to the protected mode ! system to read them from there before the area is overwritten ! for buffer-blocks. ! ! NOTE! These had better be the same as in bootsect.s! .globl begtext, begdata, begbss, endtext, enddata, endbss .text begtext: .data begdata: .bss begbss: .text entry start start: INITSEG = 0x9000 ! we move boot here - out of the way SYSSEG = 0x1000 ! system loaded at 0x10000 (65536). SETUPSEG = 0x9020 ! this is the current segment ! ok, the read went well so we get current cursor position and save it for ! posterity. mov ax,#INITSEG ! this is done in bootsect already, but... mov ds,ax mov ah,#0x03 ! read cursor pos xor bh,bh int 0x10 ! save it in known place, con_init fetches mov ax,#SETUPSEG mov es,ax mov ah,#0x03 xor bh,bh int 0x10 mov cx,#24 mov bx,#0x0007 mov bp,#msg2 mov ax,#0x1301 int 0x10 mov [0],dx ! it from 0x90000. ! Get memory size (all mem, kB) mov ah,#0x88 int 0x15 mov [2],ax !Print memory size mov ah,#0x03 xor bh,bh int 0x10 mov cx,#20 mov bx,#0x0007 mov bp,#msg3 mov ax,#0x1301 int 0x10 mov dx,[2] add dx,#0x0400 mov cx,#4 jmp print_hex print_hex: mov ax,#0x0E0F rol dx,#4 and al,dl cmp al,#0x0A jb ltA jnb nltA ltA: add al,#0x30 jmp ctnp nltA: add al,#0x37 jmp ctnp ctnp: int 0x10 loop print_hex msg2: .byte 13, 10 .ascii "Now we are in SETUP" .byte 13, 10, 13, 10 msg3: .byte 13, 10 .ascii "Total Memory Size:" .byte 13, 10, 13, 10 .text endtext: .data enddata: .bss endbss: ``` ![实验楼](https://dn-simplecloud.shiyanlou.com/2890681482733841421-wm) 实验结果： ![实验楼](https://dn-simplecloud.shiyanlou.com/2890681482733737095-wm)

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