GRUB 분석중에 화면출력

    movw    $ABS(disk_address_packet), %si
...
...
    /*  
     * disk address packet :
     *   
     * Offset  Size    Description     (Table 00272)
     * 00h    BYTE    size of packet (10h or 18h)
     * 01h    BYTE    reserved (0) 
     * 02h    WORD    number of blocks to transfer (max 007Fh for Phoenix EDD)
     * 04h    DWORD   -> transfer buffer
     * 08h    QWORD   starting absolute block number
     * (for non-LBA devices, compute as
     * (Cylinder*NumHeads + SelectedHead) * SectorPerTrack +
     * SelectedSector - 1
     * 10h    QWORD   (EDD-3.0, optional) 64-bit flat address of transfer buffer;
     * used if DWORD at 04h is FFFFh:FFFFh
     */
    xorw    %ax, %ax
    movw    %ax, 4(%si)
 
    incw    %ax
    /* set the mode to non-zero */
    movb    %al, -1(%si)
 
    /* the blocks */
    movw    %ax, 2(%si)
 
    /* the size and the reserved byte */
    movw    $0x0010, (%si)
 
    /* the absolute address */
    movl    ABS(kernel_sector), %ebx
    movl    %ebx, 8(%si)
    movl    ABS(kernel_sector + 4), %ebx
    movl    %ebx, 12(%si)
 
    /* the segment of buffer address */
    movw    $GRUB_BOOT_MACHINE_BUFFER_SEG, 6(%si)
...
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