操作系统学习--day2

读取其它扇区数据：

org    0x7c00
jmp    entry

entry:
    mov    ax,cs
    mov    ds,ax
    mov    es,ax

    mov    ax,msg
    mov    bp,ax
    mov    cx,26
    mov    ax,0x1301
    mov    bx,000ch
    mov    dl,0
    int 10h

;读扇区：ah=02h
    mov    ax,0x0820
    mov    es,ax
    mov    ch,0        ;柱面
    mov    dh,0        ;磁头
    mov    cl,2        ;扇区

    mov    ah,0x02
    mov    al,1        ;扇区数
    mov    bx,0        ;ES:BX--缓冲区数据
    mov    dl,0x00        ;驱动器:00H~7FH软盘，80H~0FFH硬盘
    int    0x13

msg    db    ‘This is program by myself!‘
    times    510-($-$$) db 0
    dw    0xaa55

拓展：

　　循环读取扇区数据

org    0x7c00
jmp    entry

entry:
    mov    ax,cs
    mov    ds,ax
    mov    es,ax

    mov    ax,msg
    mov    bp,ax
    mov    cx,26
    mov    ax,0x1301
    mov    bx,000ch
    mov    dl,0
    int 10h

;读扇区：ah=02h
    mov    ax,0x0820
    mov    es,ax
    mov    ch,0        ;柱面
    mov    dh,0        ;磁头
    mov    cl,2        ;扇区

readloop:
    mov    ah,0x02
    mov    al,1        ;扇区数
    mov    bx,0        ;ES:BX--缓冲区数据
    mov    dl,0x00        ;驱动器:00H~7FH软盘，80H~0FFH硬盘
    int    0x13
    jnc    next
    mov    ax,0x00
    mov    dl,0x00
    int 0x13        ;重置驱动器
    jmp    readloop
next:
    mov    ax,es
    add    ax,0x20
    mov    es,ax
    inc    cl
    cmp    cl,18        ;最多读取18个扇区
    jbe    readloop

msg    db    ‘This is program by myself!‘
    times    510-($-$$) db 0
    dw    0xaa55