path: root/kernel.s

    global  _main

_main:
    mov     ax, [now_screenid]
    mov     cx, 0x1000
    mul     cx
    sub     ax, 0x1000
    add     ax, 0x0050
    mov     [cs:shell_seg], ax
    
    mov     sp, 0xF6F6
    mov     word [local_var_size],local_var_end
    sub     word [local_var_size],local_var_start
    mov     ax, word [local_var_size]
    cmp     ax, 6144
    je      show_6144
    call    putint
    
show_6144:
set_environment:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
;--------------------------------------------------
do_memory_control:
    add     ax, 0x17
    cli
    mov     [es:0x140], ax
    mov     [es:0x142], cs
    sti
    jmp     do_memory_control_end
    mov     ax, 0x5301 
    xor     bx, bx 
    int     0x15 
    mov     ax, 0x530E 
    xor     bx, bx 
    mov     cx, 0x0102 
    int     0x15 
    mov     ax, 0x5307
    mov     bx, 0x0001
    mov     cx, 0x0003 
    int     0x15
    iret
do_memory_control_end:
    pop     es
;--------------------------------------------------
reboot_int:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x17
    cli
    mov     [es:0x144], ax
    mov     [es:0x146], cs
    sti
    jmp     short reboot_int_end
    mov     al, 0x0E
    mov     dx, 0xCF9
    out     dx, al
    mov     al, 0x06
    out     dx, al
    mov     al, 0xFE
    out     0x64, al
    mov     ax,0x0040
    push    ax
    pop     ds
    xor     ax, ax
    mov     es, ax
    mov     word [es:0x0027], 0x1234
    mov     ax, 0xFFFF
    push    ax
    mov     ax, 0x0000
    push    ax
    mov     ax, 0x1000
    mov     ss, ax
    mov     sp, 0xf000
    mov     ax, 0x5307
    mov     bx, 0x0001
    mov     cx, 0x0003 
    int     0x15
reboot_int_end:
    pop     es
;--------------------------------------------------

set_keyboard_break:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x2C
    cli

    mov     si, [es:0x24]
    mov     di, [es:0x26]
    mov     [es:0x324], si
    mov     [es:0x326], di
    mov     [es:0x24], ax
    mov     [es:0x26], cs

    sti
    jmp     near set_keyboard_end_break
    int     0xC9
    iret

set_keyboard_end_break:
    pop     es
    
    
;------------------------------------------------------
set_keyboard:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x2C
    cli
    mov     si, [es:0x54]
    mov     di, [es:0x56]
    mov     [es:0x354], si
    mov     [es:0x356], di
    mov     [es:0x54], ax
    mov     [es:0x56], cs

    sti
    jmp     near set_keyboard_end
code_for_scancode:
    pushf
    
;----------------------------------
    jnc     end_for_scancode
    cmp     ah, 0x4f
    jne     end_for_scancode
;----------------------------------
    jmp cencel_10101092
    push    ax
    push    es
check_kb_buf:
    xor     ax, ax

    push    ax
    pop     es
    mov     ax, [es:0x41C]
    sub     ax, [es:0x41A]
    cmp     ax, 24
    ja      clear_kb_buf
    jmp     no_clear_kb_buf
clear_kb_buf:
    mov     ax, [es:0x41A]
    add     ax, 2
    cmp     ax, 0x3C
    jbe     gosll
    mov     ax, 0x1E
gosll:
    mov     [es:0x41C], ax
    xor     ah, ah
    int     0x16
    jmp     check_kb_buf
no_clear_kb_buf:
    pop     es
    pop     ax
cencel_10101092:

;----------------------------------
    mov     [cs:scancode_int_buf], al
    push    ax
    push    bx
    push    cx
    push    dx
    push    es
    
    mov     ah, [cs:scancode_int_buf]

    mov     dx, cs
    mov     es, dx

    mov     dx, [es:scancodebuf-0x0C]
    mov     [es:scancodebuf-0x0E], dx
    
    mov     dx, [es:scancodebuf-0x0A]
    mov     [es:scancodebuf-0x0C], dx
    
    mov     dx, [es:scancodebuf-0x08]
    mov     [es:scancodebuf-0x0A], dx
    
    mov     dx, [es:scancodebuf-0x06]
    mov     [es:scancodebuf-0x08], dx
    
    mov     dx, [es:scancodebuf-0x04]
    mov     [es:scancodebuf-0x06], dx
    
    mov     dx, [es:scancodebuf-0x02]
    mov     [es:scancodebuf-0x04], dx
    
    mov     dx, [es:scancodebuf-0x00]
    mov     [es:scancodebuf-0x02], dx
    
    mov     [es:scancodebuf], ax
    mov     cx, 0x02
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x58
    je      f12_break

    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x44
    je      f10_showdatetime
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x43
    je      f9_showinfo
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x3B
    je      f1_switch_to_screen_1
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x3C
    je      f2_switch_to_screen_2
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x3D
    je      f3_switch_to_screen_3
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x3E
    je      f4_switch_to_screen_4
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x3F
    je      f5_switch_to_screen_5
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x40
    je      f6_switch_to_screen_6
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x41
    je      f7_switch_to_screen_7
    
    lea     bx, [es:scancodebufp+0x0F]
    cmp     byte [es:bx], 0x42
    je      f8_switch_to_screen_8
    
    lea     bx, [es:scancodebufp+0x09]
    
    cmp     byte [es:bx], 0xE0
    jne     not_ctrl_break
    add     bx, cx
    
    cmp     byte [es:bx], 0x46
    jne     not_ctrl_break
    add     bx, cx
    
    cmp     byte [es:bx], 0xE0
    jne     not_ctrl_break
    add     bx, cx
    
    cmp     byte [es:bx], 0xC6
    jne     not_ctrl_break
    
f12_break:  

    mov     word [cs:sector_to_load_ax], ax 
    
    xor     bx, bx
    mov     [es:scancodebuf-0x00], bx
    mov     [es:scancodebuf-0x02], bx
    mov     [es:scancodebuf-0x04], bx
    mov     [es:scancodebuf-0x06], bx
    mov     [es:scancodebuf-0x08], bx
    mov     [es:scancodebuf-0x0A], bx
    
    cmp     word [cs:scancode_processing], 0x00
    jne     not_ctrl_break
    
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, ' '
    int     0x10
    
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, '['
    int     0x10
    mov     al, '^'
    int     0x10
    mov     al, 'B'
    int     0x10
    mov     al, 'r'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, 'a'
    int     0x10
    mov     al, 'k'
    int     0x10
    mov     al, ']'
    int     0x10

    mov     word [cs:break_imm], 0x01
    mov     word [cs:scancode_processing], 0x01
    jmp     not_ctrl_break
    
f9_showinfo:
    mov     ax, [cs:view_step_now]
    inc     ax
    mov     [cs:view_step_now], ax
    dec     ax
    and     ax, [cs:view_delaycnt]
    mov     [cs:view_original], ax
    mov     ax, 0xB800
    mov     es, ax
    mov     ax, word [es:0x009C]
    mov     cx, word [es:0x009E]
    mov     word [cs:view_screenbuffer], ax
    mov     word [cs:view_screenbuffer+0x02], cx
    mov     byte [es:0x009C],'F'
    mov     byte [es:0x009D],0x4E ; 0x07; 01001110
    mov     cx, '0'
    add     cx, word [cs:now_screenid]
    mov     byte [es:0x009E],cl
    mov     byte [es:0x009F],0x4E
    mov     word [cs:view_length], 0x02
    jmp     not_ctrl_break
    
f10_showdatetime:
    
    mov     ax, [cs:view_step_now]
    inc     ax
    mov     [cs:view_step_now], ax
    dec     ax
    and     ax, [cs:view_delaycnt]
    mov     [cs:view_original], ax
    mov     ax, 0xB800
    mov     es, ax
    mov     bp, 0x74
    
    cld
    
    mov     cx, 160
    sub     cx, bp
    mov     word [cs:view_start], bp
    mov     word [cs:view_length], cx
    
    push    es
    push    ds
    push    di
    push    si
    
    push    es
    pop     ds
    
    
    
    push    cs
    pop     es
    
    mov     si, bp
    mov     di, view_screenbuffer
    
    rep     movsb
    
    pop     si
    pop     di
    pop     ds
    pop     es

    mov     ah, 0x04
    int     0x1A
    mov     al, ch
    xor     ah, ah
    
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp

    mov     ah, 0x04
    int     0x1A
    mov     al, cl
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],'/'
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     ah, 0x04
    int     0x1A
    mov     al, dh
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],'/'
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     al, dl
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],' '
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     ah, 0x02
    int     0x1A
    mov     al, ch
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],':'
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     al, cl
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],':'
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     al, dh
    xor     ah, ah
    call    putint_td
    
    mov     byte [es:bp],dl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],dh
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],' '
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     byte [es:bp],'P'
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    mov     cx, '0'
    add     cx, word [cs:now_screenid]
    
    mov     byte [es:bp],cl
    inc     bp
    mov     byte [es:bp],0x4E
    inc     bp
    
    
    jmp     not_ctrl_break
    
f1_switch_to_screen_1:
    mov     word [cs:to_screenid], 0x1
    cmp     word [cs:now_screenid], 0x1
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x180
    jmp     switch_to_screen_all
    
f2_switch_to_screen_2:
    mov     word [cs:to_screenid], 0x2
    cmp     word [cs:now_screenid], 0x2
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x300
    jmp     switch_to_screen_all
    
f3_switch_to_screen_3:
    mov     word [cs:to_screenid], 0x3
    cmp     word [cs:now_screenid],0x3
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x480
    jmp     switch_to_screen_all
    
f4_switch_to_screen_4:
    mov     word [cs:to_screenid], 0x4
    cmp     word [cs:now_screenid],0x4
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x600
    jmp     switch_to_screen_all
    
f5_switch_to_screen_5:
    mov     word [cs:to_screenid], 0x5
    cmp     word [cs:now_screenid],0x5
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x780
    jmp     switch_to_screen_all
    
f6_switch_to_screen_6:
    mov     word [cs:to_screenid], 0x6
    cmp     word [cs:now_screenid],0x6
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0x900
    jmp     switch_to_screen_all
    
f7_switch_to_screen_7:
    mov     word [cs:to_screenid], 0x7
    cmp     word [cs:now_screenid],0x7
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0xA80
    jmp     switch_to_screen_all
    
f8_switch_to_screen_8:
    mov     word [cs:to_screenid], 0x8
    cmp     word [cs:now_screenid],0x8
    je      not_ctrl_break
    mov     word [cs:to_screenid_seg], 0xC00
    jmp     switch_to_screen_all

switch_to_screen_all:

    xor     bx, bx
    mov     [es:scancodebuf-0x00], bx
    mov     [es:scancodebuf-0x02], bx
    mov     [es:scancodebuf-0x04], bx
    mov     [es:scancodebuf-0x06], bx
    mov     [es:scancodebuf-0x08], bx
    mov     [es:scancodebuf-0x0A], bx
    
    cmp     word [cs:switch_imm], 0x00
    jne     quit_switch_to_screen_all
    
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, ' '
    int     0x10

    mov     word [cs:switch_imm], 0x01
    jmp     not_ctrl_break

quit_switch_to_screen_all:
not_ctrl_break:
    pop     es
    pop     dx
    pop     cx
    pop     bx
    pop     ax
    
end_for_scancode:
    popf
    int     0xD5
    
    iret
set_keyboard_end:
    pop     es

;--------------------------------------------------
set_timer:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x2C
    cli

    mov     si, [es:0x20]
    mov     di, [es:0x22]
    mov     [es:0x320], si
    mov     [es:0x322], di
    mov     [es:0x20], ax
    mov     [es:0x22], cs
    sti

    jmp     near set_timer_end
    
    int     0xC8
    pushf
    
;--------------


    push    ax
    push    es
 
recheck_kb_buf:
    xor     ax, ax

    push    ax
    pop     es
    mov     ax, [es:0x41C]
    sub     ax, [es:0x41A]
    cmp     ax, 24
    ja      reclear_kb_buf
    jmp     no_reclear_kb_buf
reclear_kb_buf:
    xor     ah, ah
    int     0x16
    mov     ax, [es:0x41A]
    add     ax, 2
    cmp     ax, 0x3C
    jbe     gosllww
    mov     ax, 0x1E
gosllww:
    mov     [es:0x41C], ax
    
    jmp     recheck_kb_buf
no_reclear_kb_buf:
    pop     es
   pop      ax
   
cencel_10101093:
    
;--------------------------------------------------
update_timer:
    inc     word [cs:view_step_now]
;--------------------------------------------------

break_imm_function:
    cli
    cmp     word [cs:break_imm],0x00
    je      quit_break_imm_function
    
    mov         word [cs:break_imm],0x00
    mov         word [cs:scancode_processing], 0x02
    mov         ax, [cs:sector_to_load_ax];
    cmp         word [cs:sector_to_load], 0x3021 ;
    jne         break_imm_not_shell_load_break
    mov         ax, 0xFFFF
    jmp         break_imm_shell_load_break
    
break_imm_not_shell_load_break:
    mov         word [cs:sector_to_load], 0x3021
    sti
    popf
    jmp         program_exit_no_to_save
    
break_imm_shell_load_break:
    sti
    popf
    jmp         program_exit
quit_break_imm_function:
    popf
    pushf


;--------------------------------------------------
view_screen_timer:
    cmp     word [cs:view_length], 0x00
    je      quit2_view_screen_timer
    cli
    push    ax
    push    cx
    
    mov     ax, [cs:view_step_now]
    and     ax, [cs:view_delaycnt]
    cmp     ax, [cs:view_original]
    jne     quit_view_screen_timer
    
    push    es
    mov     ax, 0xB800
    mov     es, ax
    
    cld
    
    mov     cx, [cs:view_length]
    
    push    es
    push    ds
    push    di
    push    si
    
    push    cs
    pop     ds
    
    nop 
    nop
    mov     di, [cs:view_start]
    mov     si, view_screenbuffer
    
    rep     movsb
    
    pop     si
    pop     di
    pop     ds
    pop     es


    mov     word [cs:view_length], 0x00
    
    
    pop     es

quit_view_screen_timer:
    pop     cx
    pop     ax
quit2_view_screen_timer:
;--------------------------------------------------
switch_function:
    cmp     word [cs:switch_imm],0x00
    je      quit_switch_function
    mov     word [cs:switch_imm],0x00
    cli
    push    ax
    push    bx
    push    cx
    push    dx
    push    es
    push    ds
    push    ss
    push    sp
    push    bp
    push    si
    push    di
    nop
    nop
    nop
    nop
    
store_data_to_local:

save_reg_to_now:
    mov     ax, ss
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, sp
    mov     di, register_buf
    mov     cx, 15
    cld
    rep     movsw

    mov     [cs:register_buf+6], sp

save_screen_to_now:
    mov     ax, 0xb800
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, screen_data_buf
    mov     cx, 1000
    cld
    rep     movsd

save_bda_to_now:
    mov     ax, 0x40
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, bios_bda_databuf
    mov     cx, 64
    cld
    rep     movsd
    
save_ebda_to_now:
    mov     ax, 0x9FC0
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, bios_ebda_databuf
    mov     cx, 256
    cld
    rep     movsd

save_now_to_archive:    
    mov     ax, cs
    mov     ds, ax
    mov     ax, [cs:now_screenid]
    mov     cx, 0x180
    mul     cx
    mov     cx, cs ; 6kb
    add     ax, cx
    mov     es, ax
    mov     si, local_var_start; now
    mov     di, local_var_start; 1
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
load_new_to_now:    
    mov     ax, cs
    mov     es, ax
    mov     ax, [cs:to_screenid]
    mov     cx, 0x180
    mul     cx
    mov     cx, cs ; 6kb
    add     ax, cx
    mov     ds, ax
    mov     di, local_var_start; now
    mov     si, local_var_start; 1
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
load_now_to_screen:
    mov     ax, 0xb800
    mov     es, ax
    mov     ax, cs
    mov     ds, ax
    mov     di, 0x0
    mov     si, screen_data_buf
    mov     cx, 1000
    cld
    rep     movsd
load_now_to_bda:
    mov     ax, 0x40
    mov     es, ax
    mov     ax, cs
    mov     ds, ax
    mov     di, 0x0
    mov     si, bios_bda_databuf
    mov     cx, 64
    cld
    rep     movsd
    
load_now_to_ebda:
    mov     ax, 0x9FC0
    mov     es, ax
    mov     ax, cs
    mov     ds, ax  
    mov     di, 0x0
    mov     si, bios_ebda_databuf
    mov     cx, 256
    cld
    rep     movsd

load_now_prework:
    mov     sp, [cs:register_buf+6]
    mov     ss, [cs:register_buf+8]
    
load_now_to_reg:
    mov     ax, ss
    mov     es, ax
    mov     ax, cs
    mov     ds, ax
    mov     di, sp
    mov     si, register_buf
    mov     cx, 15
    cld
    rep     movsw
    
    
    
    pop     di
    pop     si
    pop     bp
    pop     ax
    pop     ax
    pop     ds
    
    
    
    
    
    mov     dx, 0x3D4
    mov     al, 0x0E
    out     dx, al          ; read high byte

    mov     dx, 0x3D5
    in      al, dx
    mov     ch, al

    mov     dx, 0x3D4
    mov     al, 0x0F
    out     dx, al          ; read low byte

    mov     dx, 0x3D5
    in      al, dx
    mov     cl, al

    mov     dx, 0x3D4
    mov     al, 0x0E
    out     dx, al          ; send high byte

    mov     dx, 0x3D5
    mov     al, ch
    out     dx, al

    mov     dx, 0x3D4
    mov     al, 0x0F
    out     dx, al          ; send low byte

    mov     dx, 0x3D5
    mov     al, cl
    out     dx, al
    
    pop     es
    pop     dx
    pop     cx
    pop     bx
    pop     ax
    push    ax
    push    bx
    push    cx
    push    dx
    push    es
    
    mov     ax, [cs:view_step_now]
    inc     ax
    mov     [cs:view_step_now], ax
    dec     ax
    and     ax, [cs:view_delaycnt]
    mov     [cs:view_original], ax
    mov     ax, 0xB800
    mov     es, ax
    cmp     word [cs:view_length], 0x00
    jne     not_need_savscr
    mov     ax, word [es:0x009C]
    mov     cx, word [es:0x009E]
    mov     word [cs:view_start], 0x9C
    mov     word [cs:view_screenbuffer], ax
    mov     word [cs:view_screenbuffer+0x02], cx
    mov     word [cs:view_length], 0x04
not_need_savscr:
    mov     cx, '0'
    add     cx, word [cs:now_screenid]
    mov     byte [es:0x009C],cl
    mov     byte [es:0x009D],0x4E
    mov     cx, '0'
    add     cx, word [cs:to_screenid]
    mov     byte [es:0x009E],cl
    mov     byte [es:0x009F],0x4E
    
    
    mov     ax, [cs:to_screenid]
    mov     cx, 0x1000
    mul     cx
    sub     ax, 0x1000
    add     ax, 0x0050
    mov     [cs:shell_seg], ax
    mov     ax, [cs:to_screenid]
    mov     [cs:now_screenid], ax

    pop     es
    pop     dx
    pop     cx
    pop     bx
    pop     ax  

check_is_it_not_loadshell:
    cmp     word [cs:register_buf+24], start_point
    nop
    nop
    nop
    jne     quit_switch_function

    mov     sp, [cs:initialize_sp]
    mov     ax, start_point
    mov     bx, cs
    mov     es, bx
    mov     ss, bx
    mov     ds, bx
    push        ax

    ret
    rdtsc
    

quit_switch_function:
;--------------------------------------------------
timer_ret:
    
    
    
    popf
    iret

set_timer_end:
    pop     es
;--------------------------------------------------

;--------------------------------------------------
set_envbuf:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x18
    cli
    mov     [es:0x148], ax
    mov     [es:0x14A], cs
    sti
    jmp     near set_envbuf_end

    push    ax
    mov     ax, [ds:0xFFFE]
    mov     es, ax
    mov     [es:yotshell_sizeofenv], cx
    mov     [es:yotshell_ptrofenv], si
    
    pop     ax
    mov     di, yotshell_env_buf
    iret
set_envbuf_end:
    pop     es
;-------------------------------------------------- 
save_envbuf:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x18
    cli
    mov     [es:0x14C], ax
    mov     [es:0x14E], cs
    sti
    jmp     near save_envbuf_end
    call    save_env_buf_intcall
    iret
save_envbuf_end:
    pop     es
;-------------------------------------------------- 
load_envbuf:
    xor     ax, ax
    push    es
    mov     es, ax
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    pop     ax
    sub     sp, 2
    ret
    add     ax, 0x18
    cli
    mov     [es:0x150], ax
    mov     [es:0x152], cs
    sti
    jmp     near load_envbuf_end
    call    load_env_buf_intcall
    iret
load_envbuf_end:
    pop     es
;-------------------------------------------------- 

jmp envbuf_functions_end

load_env_buf_intcall:
    push    di
    push    ds
    push    es
    push    cx
    push    si
    pushf
    cld
    push    ds
    pop     es
    push    cs
    pop     ds
    mov     cx, [cs:yotshell_sizeofenv]
    cmp     cx, 0xBAAD
    je      load_env_buf_unseted
    xor     ax, ax
    cmp     [cs:yotshell_envseted], ax
    je      load_env_buf_unseted
    mov     ax, cx
    mov     di, [cs:yotshell_ptrofenv]
    mov     si, yotshell_env_buf
    cld
    rep     movsb
    
    jmp     load_env_buf_step2
load_env_buf_unseted:
    xor     ax, ax
load_env_buf_step2:
    popf
    pop     si  
    pop     cx
    pop     es
    pop     ds
    pop     di
    ret

save_env_buf:
    push    di
    push    ds
    push    cx
    push    ax
    push    si
    pushf
    push    ds
    pop     es
    cld
    mov     cl, 0x01
    mov     [yotshell_envseted], cl
    mov     cx, [yotshell_sizeofenv]
    cmp     cx, 0xBAAD
    je      save_env_buf_unseted
    mov     si, [yotshell_ptrofenv]
    mov     di, yotshell_env_buf
    mov     ax, [shell_seg]
    mov     ds, ax
    cld
    rep     movsb
save_env_buf_unseted:
    popf
    pop     si
    pop     ax
    pop     cx
    pop     ds
    pop     di
    ret
    
save_env_buf_intcall:
    push    di
    push    es
    push    cx
    push    ax
    push    si
    pushf
    cld
    mov     ax, [ds:0xFFFE]
    mov     es, ax
    mov     cl, 0x01
    mov     [es:yotshell_envseted], cl
    mov     cx, [es:yotshell_sizeofenv]
    cmp     cx, 0xBAAD
    je      save_env_buf_unseted_intcall
save_env_buf_unseted_intcall:
    mov     si, [es:yotshell_ptrofenv]
    mov     di, yotshell_env_buf
    cld
    rep     movsb
    popf
    pop     si
    pop     ax
    pop     cx
    pop     es
    pop     di
    ret
envbuf_functions_end:

    mov     word [initialize_sp], sp
    pushf
    push    cs
    mov     ax, start_point
    push    ax
    pushf
    push    ax
    push    bx
    push    cx
    push    dx
    push    es
    push    ds
    push    ss
    push    sp
    push    bp
    push    si
    push    di
    
    push    es

    
    mov     ax, 0x0050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF  
loop0050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop0050
    
    mov     ax, 0x1050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF  
loop1050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop1050
    
    mov     ax, 0x2050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop2050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop2050
    
    mov     ax, 0x3050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop3050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop3050
    
    mov     ax, 0x4050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop4050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop4050
    
    mov     ax, 0x5050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop5050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop5050
    
    mov     ax, 0x6050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop6050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop6050
    
    mov     ax, 0x7050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop7050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop7050
    
    mov     ax, 0x8050
    push    ax
    pop     es
    mov     bx, 0xFFFF
    mov     cx, 0xFFFF
loop8050:
    mov     byte [es:bx], 0x0
    dec     bx
    loop    loop8050
    



    
    pop     es
        
init_save_reg_to_now:
    mov     ax, ss
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, sp
    mov     di, register_buf
    mov     cx, 15
    cld
    rep     movsw
    



    
    add     sp, 30
    sub     word [cs:register_buf+6], 8


    
init_save_screen_to_now:
    mov     ax, 0xb800
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, screen_data_buf
    mov     cx, 1000
    cld
    rep     movsd

init_save_bda_to_now:
    mov     ax, 0x40
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, bios_bda_databuf
    mov     cx, 64
    cld
    rep     movsd
    
init_save_ebda_to_now:
    mov     ax, 0x9FC0
    mov     ds, ax
    mov     ax, cs
    mov     es, ax
    mov     si, 0x0
    mov     di, bios_ebda_databuf
    mov     cx, 256
    cld
    rep     movsd
    
to_archive_1:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x180 
    mov     es, ax
    mov     si, local_var_start
    mov     di, local_var_start
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
    
to_archive_2:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x300 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
to_archive_3:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x480 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
to_archive_4:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x600 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
to_archive_5:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x780 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
to_archive_6:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0x900 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
to_archive_7:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0xA80 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    ;mov        word [es:register_buf+2], 0x6050
    
to_archive_8:   
    mov     ax, cs
    mov     ds, ax
    add     ax, 0xC00 ; 6kb
    mov     es, ax
    mov     si, local_var_start;
    mov     di, local_var_start;
    mov     cx, [cs:local_var_size]
    cld
    rep     movsb
    
;--------------------------------------------------
start_point:
    
    nop 
load_shell_from_floppy:
    sti
    xor         bx, bx
    mov     [scancodebuf-0x00], bx
    mov     [scancodebuf-0x02], bx
    mov     [scancodebuf-0x04], bx
    mov     [scancodebuf-0x06], bx
    mov     [scancodebuf-0x08], bx
    mov     [scancodebuf-0x0A], bx
    mov     word [cs:break_imm], bx
    
    L1: mov ah,11h  ; check keyboard buffer
    int 16h     ; any key pressed?
    jz  noKey   ; no: exit now
    mov ah,10h  ; yes: remove from buffer
    int 16h
    jmp L1  ; no: check buffer again

noKey:  ; no key pressed
    or  al,1    ; clear zero flag

    mov     ax, [shell_seg]
    mov     es, ax
    
    mov     ax, [sector_to_load]        ; sector offset ; 10
    dec     ax
    mov     dx, ax
    and     ax, 0xFFF
    shr     dx, 0x0C
    inc     dx
    shl     dx, 0x03

    mov     cx,0xFFFF
    a0fffloop:
        dec     cx
    loopnz  a0fffloop
    mov     cx,0xFFFF
    a0fffloop1:
        dec     cx
    
    loopnz  a0fffloop1
    mov     cx,0xFFFF
    a0fffloop2:
        dec     cx
    
    loopnz  a0fffloop2
    mov     cx,0xFFFF
    a0fffloop3:
        dec     cx
    
    loopnz  a0fffloop3
    mov     cx,0xFFFF
    a0fffloop4:
        dec     cx
    
    loopnz  a0fffloop4
    mov     cx,0xFFFF
    a0fffloop5:
        dec     cx
    
    loopnz  a0fffloop5
    
    call    convchs
    cmp     ax, 0xFEFE; 0xFEFE & 0xFFF - 1
    je      load_nothing_img
    
    call    convchsformat
    xor         bx, bx
    xor     si, si
    xor     di, di
    int     0x13
    jmp     load_disk_ok
    
load_nothing_img:
    jmp         load_shell_failed
;--------------------------------------------------
load_disk_ok:
view_loader_message:
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, 0x0d
    int     0x10
    mov     al, 0x0a
    int     0x10
;--------------------------------------------------
fake_loader:
    db      0xE8
    add     al, [bx+si]
    db      0xEB
    db      0x05
    db      0x58
;--------------------------------------------------
virtual_device:
    db      0x83
    in      al, dx
    db      0x02
    ret
;--------------------------------------------------
real_loader:
    jmp     near very_very_far_func
    jmp     program_exit
;--------------------------------------------------
load_shell_failed:
    call    putint
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, 'L'
    int     0x10
    mov     al, 'o'
    int     0x10
    mov     al, 'a'
    int     0x10
    mov     al, 'd'
    int     0x10
    mov     al, ' '
    int     0x10
    cmp     word [sector_to_load], 0x3021
    jne     load_prog_failed_str
    mov     al, 'S'
    int     0x10
    mov     al, 'h'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, 'l'
    int     0x10
    mov     al, 'l'
    int     0x10
    jmp     load_prog_failed_str_continue
load_prog_failed_str:
    pusha
    mov     ax, [sector_to_load]
    call    putint
    popa
load_prog_failed_str_continue:
    mov     al, ' '
    int     0x10
    mov     al, 'F'
    int     0x10
    mov     al, 'a'
    int     0x10
    mov     al, 'i'
    int     0x10
    mov     al, 'l'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, 'd'
    int     0x10
    mov     al, '.'
    int     0x10
    mov     al, ' '
    int     0x10
    cmp     word [sector_to_load], 0x3021
    je      shell_call_load_failed
    mov     word [sector_to_load], 0x3021
shell_call_load_failed:
    jmp     load_shell_from_floppy
;--------------------------------------------------
very_very_far_func:

    mov     si, 0xF6F6
    mov     [si], sp
    
    mov     bx, [shell_seg]
    mov     ds, bx
    mov     es, bx
    mov     ss, bx
    mov     bx, 0xFFFF
    mov     si, bx
    mov     dx, 0xFFF8
    mov     sp, dx
    mov     bp, dx
    mov     [si-0x0001], cs
    add     ax, 0x0A
    mov     [si-0x0003], ax
    mov     dl, 0xFA
    mov     [si-0x0007], dx
    mov     dl, 0x5A
    mov     [si-0x0005], dl
    mov     dl, 0xCB
    mov     [si-0x0004], dl
    mov     word [cs:scancode_processing], 0x00
    mov     word [cs:ok_for_once_shell], 0x01
    
    db      0xEA
    dw      0x0000
shell_seg:
    dw      0x0050

;--------------------------------------------------
program_exit_no_to_save:
    mov     word [cs:scancode_processing], 0x02
    mov     sp, [cs:0xF6F6]
    mov     bx, cs
    mov     ds, bx
    mov     es, bx
    mov     ss, bx
    
    mov     dx, ax

    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, 0x0D
    int     0x10
    mov     al, 0x0A
    int     0x10
    mov     al, 'E'
    int     0x10
    mov     al, 'x'
    int     0x10
    mov     al, 'i'
    int     0x10
    mov     al, 't'
    int     0x10
    mov     al, ' '
    int     0x10
    mov     al, 'C'
    int     0x10
    mov     al, 'o'
    int     0x10
    mov     al, 'd'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, ':'
    int     0x10
    mov     al, ' '
    int     0x10
    mov     ax, dx
    call    putint

    mov     word [sector_to_load], 0x3021
    jmp     load_shell_from_floppy
;--------------------------------------------------
program_exit:

    mov     word [cs:scancode_processing], 0x02
    mov     sp, [cs:0xF6F6]
    mov     bx, cs
    mov     ds, bx
    mov     es, bx
    mov     ss, bx
    mov     dx, ax
    cmp     word [sector_to_load], 0x3021
    jne     not_shell_successful_call
    cmp     dx, 0xFFFF
    je      not_shell_successful_call
    cmp     dx, 0x0
    je      not_shell_successful_call

    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, 'C'
    int     0x10
    mov     al, 'a'
    int     0x10
    mov     al, 'l'
    int     0x10
    mov     al, 'l'
    int     0x10
    mov     al, 'i'
    int     0x10
    mov     al, 'n'
    int     0x10
    mov     al, 'g'
    int     0x10
    mov     al, ' '
    int     0x10
    mov     al, 'P'
    int     0x10
    mov     al, 'r'
    int     0x10
    mov     al, 'o'
    int     0x10
    mov     al, 'g'
    int     0x10
    mov     al, 'r'
    int     0x10
    mov     al, 'a'
    int     0x10
    mov     al, 'm'
    int     0x10
    mov     al, ' '
    int     0x10
    mov     ax, dx
    call    putint
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, '.'
    int     0x10
    mov     al, '.'
    int     0x10
    mov     al, '.'
    int     0x10
    mov     ax, dx
    jmp     not_to_need_show_exitcode
not_shell_successful_call:
    mov     bx, 0x0007
    mov     ah, 0x0E
    mov     al, 0x0D
    int     0x10
    mov     al, 0x0A
    int     0x10
    mov     al, 'E'
    int     0x10
    mov     al, 'x'
    int     0x10
    mov     al, 'i'
    int     0x10
    mov     al, 't'
    int     0x10
    mov     al, ' '
    int     0x10
    mov     al, 'C'
    int     0x10
    mov     al, 'o'
    int     0x10
    mov     al, 'd'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, ':'
    int     0x10
    mov     al, ' '
    int     0x10

    mov     ax, dx
    call    putint
not_to_need_show_exitcode:
    

    cmp     word [sector_to_load], 0x3021
    je      shell_call
    mov     ax, 0x3021
shell_call:
    cmp     ax, 0xFFFF
    jne     shell_call_continue
    mov     ax, 0x3021
shell_call_continue:
    cmp     ax, 0x0
    jne     shell_call_continue2
    mov     ax, 0x3021
shell_call_continue2:
    cmp     word [sector_to_load], 0x3021
    jne     not_to_save
    call    save_env_buf
not_to_save:
    mov     [sector_to_load], ax
    jmp     load_shell_from_floppy

;--------------------------------------------------
putint:             ; ax=argument
    pusha
    mov     di, 0   ; dest index
    mov     si, 10  ; divisor, ax=dividend
    
    putint_divloop:
        mov     dx, 0   ; clear upper bits
        div     si
        add     dx, '0'
        mov     byte [putintbuf+di], dl
        inc     di
        cmp     ax, 0
        ja      putint_divloop

    mov     ah, 0x0e
    mov     bx, 0x0007
    
    putint_print:
        dec     di
        mov     al, byte [putintbuf+di]
        int     0x10
        cmp     di, 0
        ja      putint_print
    
    mov     ah, 0x0e
    mov     bx, 0x0007
    
    popa
    ret
;--------------------------------------------------
putint_td:              ; ax=argument
    push    cx
    mov     cl, al
    push    bx
    push    ax
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, cl
    and     al, 0xf0
    shr     al, 4
    call    fourbit2hex
    mov     dl, al
    mov     al, cl
    and     al, 0x0f
    call    fourbit2hex
    mov     dh, al
    pop     ax
    pop     bx
    pop     cx
    ret
;--------------------------------------------------
putint_ptr:             ; ax=argument
    pusha
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, '['
    int     0x10
    popa
    pusha
    mov     di, 0   ; dest index
    mov     si, 10  ; divisor, ax=dividend
    putint_divloop_ptr:
        mov     dx, 0   ; clear upper bits
        div     si
        add     dx, '0'
        mov     byte [putintbuf+di], dl
        inc     di
        cmp     ax, 0
        ja      putint_divloop_ptr

    mov     ah, 0x0e
    mov     bx, 0x0007
    
    putint_print_ptr:
        dec     di
        mov     al, byte [putintbuf+di]
        int     0x10
        cmp     di, 0
        ja      putint_print_ptr
    
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, ']'
    int     0x10
    
    popa
    ret
;--------------------------------------------------
putint_sp:              ; ax=argument
    pusha
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, '{'
    int     0x10
    popa
    pusha
    putint_divloop_sp:
        mov     dx, 0   ; clear upper bits
        div     si
        add     dx, '0'
        mov     byte [putintbuf+di], dl
        inc     di
        cmp     ax, 0
        ja      putint_divloop_sp

    mov     ah, 0x0e
    mov     bx, 0x0007
    
    putint_print_sp:
        dec     di
        mov     al, byte [putintbuf+di]
        int     0x10
        cmp     di, 0
        ja      putint_print_sp
    
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, '}'
    int     0x10
    
    popa
    ret
;--------------------------------------------------
putint_bp:              ; ax=argument
    pusha
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, '@'
    int     0x10
    popa
    pusha
    putint_divloop_bp:
        mov     dx, 0   ; clear upper bits
        div     si
        add     dx, '0'
        mov     byte [putintbuf+di], dl
        inc     di
        cmp     ax, 0
        ja      putint_divloop_bp

    mov     ah, 0x0e
    mov     bx, 0x0007
    
    putint_print_bp:
        dec     di
        mov     al, byte [putintbuf+di]
        int     0x10
        cmp     di, 0
        ja      putint_print_bp
    
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, '!'
    int     0x10
    
    popa
    ret
    
putcharhex:
    push    dx
    push    ax
    mov     dx, bx  ; preserve bx
    mov     ah, 0x0e
    mov     bx, 0x0007
    mov     al, cl
    and     al, 0xf0
    shr     al, 4
    call    fourbit2hex
    int     0x10
    mov     al, cl
    and     al, 0x0f
    call    fourbit2hex
    int     0x10
    mov     bx, dx  ; restore bx
    pop     ax
    pop     dx
    ret
fourbit2hex:        ; al=argument=result
    cmp     al, 10
    jae     fourbit2hex_alpha
    add     al, '0'
    ret
fourbit2hex_alpha:
    add     al, 'A' - 10
    ret 

convchs: ; LBA=AX; CHS = CBA
    pushf
    cmp     ax, 32; 0x3021
    je      vaild_LBA
    cmp     ax, word [chs_minium]
    jb      invaild_LBA
    cmp     ax, word [chs_maxium]
    ja      invaild_LBA
    jmp     vaild_LBA
invaild_LBA:
    push    bx
    mov     bx, 0x0007
    mov     ah, 0x0e
    mov     al, 'O'
    int     0x10
    mov     al, 'v'
    int     0x10
    mov     al, 'e'
    int     0x10
    mov     al, 'r'
    int     0x10
    mov     al, 'f'
    int     0x10
    mov     al, 'l'
    int     0x10
    mov     al, 'o'
    int     0x10
    mov     al, 'w'
    int     0x10
    mov     al, '.'
    int     0x10
    mov     al, '.'
    int     0x10
    mov     al, '.'
    int     0x10
    pop     bx
    mov     ax, 0xFEFE
    popf
    ret
vaild_LBA:
    push    dx
    xor     dx, dx
    mov     bx, [chs_sectors_num]
    div     bx
    inc     dx
    push    dx
    xor     dx, dx
    mov     bx, [chs_heads_num]
    div     bx
    mov     cx, ax
    mov     bx, dx
    pop     ax
    pop     dx
    popf
    ret
    
convchsformat: ; c:h:s = cx:bx:ax 
    xchg    ch, cl
    shl     cl, 0x06
    add     cl, al
    mov     al, dl
    mov     ah, 0x02
    xor     dl, dl
    mov     dh, bl

    ret

putintbuf: times 5 db 0
break_imm: dw 0x00
scancodebufp: times 7 dw 0 
scancodebuf: dw 0
scancode_int_buf: db 0x0
chs_sectors_num: dw 18
chs_heads_num: dw 0x2
chs_minium: dw 32
chs_maxium: dw 2880;2880
view_delaycnt: dw 15; 2^7
view_step_now: dw 0x0
view_original: dw 0x0; 2^7
view_screenbuffer: times 256 dw 0
view_length: dw 0
view_start: dw 0
now_screenid:   dw 0x1
now_screen_seg: dw 0x1
to_screenid:    dw 0x1
to_screenid_seg:    dw 0x1
scancode_processing:    dw 0x2 ; disable
initialize_sp: dw 0
ok_for_once_shell: dw 0
switch_imm: dw 0 

local_var_size: dw 0

local_var_start:
;-----------------------------------:
;local_var
data_tag_start: db 0xBA, 0xAD, 0xBa, 0xAD
register_buf: times 40 db 0                     ; 0x0028
sector_to_load: dw 0x3021                       ; 0x0002
sector_to_load_ax: dw 0x3021                    ; 0x0002
yotshell_sizeofenv: dw 0xBAAD ; BAAD => unset   ; 0x0002
yotshell_ptrofenv: dw 0xBAAD                    ; 0x0002
yotshell_envseted: db 0x00                      ; 0x0001
yotshell_env_buf: times 256 db 0                ; 0x0100
bios_bda_databuf: times 256 db 0                ; 0x0100
bios_ebda_databuf: times 1024 db 0              ; 0x0400
screen_data_buf: times 4000 db 0                ; 0x0FA0
data_tag_end: db 0xF0, 0x0D, 0xF0, 0x0D
res:    times 0x227 db 0 
;-------------------------------------
local_var_end: