Linux匯編寫引導扇區

最近再看《Orange‘s一個操作系統的實現》,裡面用的是intel的匯編語法，自己比較習慣AT&T的語法了，自己研究了好長時間才將代碼修改成功。

1. .code16
2. .section.text
3. .globl_start
4. _start:
5. movw%cs,%ax
6. movw%ax,%ds
7. movw%ax,%es
8. callDispStr
9. loop1:jmploop1
10. DispStr:
11. movw$BootMessage,%ax
12. movw%ax,%bp
13. movw$0x10,%cx
14. movw$0x1301,%ax
15. movw$0xc,%bx
16. movb$0,%dl
17. int$0x10
18. ret
19. BootMessage:.ascii "Hello, OS world!"
20. .org510
21. .word0xAA55

.code16指示as生成16位的代碼。While `as' normally writes only "pure" 32-bit i386 code or 64-bit x86-64 code depending on the default configuration, it also supports writing code to run in real mode or in 16-bit protected mode code segment.

編譯的話 as -o boot.o boot.s ;

ld -Ttext=0x7c00 --oformat binary -o boot.bin boot.o;

這樣就ok了～～