Subversion Repositories Kolibri OS

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;                                                               ;;

;;  MenuetOS process management, protected ring3                 ;;

;;                                                               ;;

;;  Distributed under GPL. See file COPYING for details.         ;;

;;  Copyright 2003 Ville Turjanmaa                               ;;

;;                                                               ;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

align 32

; GDT TABLE

gdts:

        dw     gdte-$-1

        dd     gdts

        dw     0

int_code_l:

os_code_l:

        dw     0xffff

        dw     0x0000

        db     0x00

        dw     11011111b *256 +10011010b

        db     0x00

int_data_l:

os_data_l:

        dw     0xffff

        dw     0x0000

        db     0x00

        dw     11011111b *256 +10010010b

        db     0x00

; --------------- APM ---------------------

apm_code_32:

        dw     0x10        ; limit 64kb

        db     0, 0, 0

        dw     11011111b *256 +10011010b

        db     0x00

apm_code_16:

        dw     0x10

        db     0, 0, 0

        dw     10011111b *256 +10011010b

        db     0x00

apm_data_16:

        dw     0x10

        db     0, 0, 0

        dw     10011111b *256 +10010010b

        db     0x00

; -----------------------------------------

app_code_l:

      dw 0xFFFF;((0x80000000-std_application_base_address) shr 12) and 0xffff

      dw 0

      db 0x40

      db cpl3

      dw G32+D32+0x6000+0x7;

app_data_l:

      dw 0xFFFF;(0x80000000-std_application_base_address) shr 12 and 0xffff

      dw 0

      db 0x40

      db drw3

      dw G32+D32+0x6000+0x7;

graph_data_l:

        dw     0x3ff

        dw     0x0000

        db     0x00

        dw     11010000b *256 +11110010b

        db     0x00

tss0_l:

      times (max_processes+10) dd 0,0

gdte:

idtreg:

     dw   8*0x41-1

     dd   idts+8

;label idts at 0xB100-8

uglobal

 tss_sceleton:

  l.back   dw 0,0

  l.esp0   dd 0

  l.ss0    dw 0,0

  l.esp1   dd 0

  l.ss1    dw 0,0

  l.esp2   dd 0

  l.ss2    dw 0,0

  l.cr3    dd 0

  l.eip    dd 0

  l.eflags dd 0

  l.eax    dd 0

  l.ecx    dd 0

  l.edx    dd 0

  l.ebx    dd 0

  l.esp    dd 0

  l.ebp    dd 0

  l.esi    dd 0

  l.edi    dd 0

  l.es     dw 0,0

  l.cs     dw 0,0

  l.ss     dw 0,0

  l.ds     dw 0,0

  l.fs     dw 0,0

  l.gs     dw 0,0

  l.ldt    dw 0,0

  l.trap   dw 0

  l.io     dw 0

endg

build_process_gdt_tss_pointer:

        mov    ecx,tss_data

        mov    edi,0

      setgdtl2:

        mov    [edi+gdts+ tss0 +0], word tss_step

        mov    [edi+gdts+ tss0 +2], cx

        mov    eax,ecx

        shr    eax,16

        mov    [edi+gdts+ tss0 +4], al

        mov    [edi+gdts+ tss0 +7], ah

        mov    [edi+gdts+ tss0 +5], word 01010000b *256 +11101001b

        add    ecx,tss_step

        add    edi,8

        cmp    edi,8*(max_processes+5)

        jbe    setgdtl2

        ret

build_interrupt_table:

        mov    edi, idts+8

        mov    esi, sys_int

        mov    ecx, 0x40

     @@:

        mov    eax, [esi]

        mov    [edi],   ax           ; lower part of offset

        mov    [edi+2], word os_code ; segment selector

        shr    eax, 16

        mov    [edi+4], word 10001110b shl 8 ; interrupt descriptor

        mov    [edi+6], ax

        add    esi, 4

        add    edi, 8

        dec    ecx

        jnz    @b

        ;mov    edi,8*0x40+idts+8

        mov    [edi + 0], word (i40 and ((1 shl 16)-1))

        mov    [edi + 2], word os_code

        mov    [edi + 4], word 11101110b*256

        mov    [edi + 6], word (i40 shr 16)

        ret

iglobal

  sys_int:

    dd e0,debug_exc,e2,e3

    dd e4,e5,e6,e7

    dd e8,e9,e10,e11

    dd e12,e13,page_fault_handler,e15

    dd except_16, e17,e18, except_19

    times 12 dd unknown_interrupt

    dd   irq0  , irq_serv.irq_1, p_irq2 ,irq_serv.irq_3

    dd   p_irq4 ,irq_serv.irq_5,p_irq6,irq_serv.irq_7

    dd   irq_serv.irq_8, irq_serv.irq_9, irq_serv.irq_10

    dd   irq_serv.irq_11,p_irq12,irqD ,p_irq14,p_irq15

    times 16 dd unknown_interrupt

    dd   i40

endg

macro save_ring3_context

{

    push    ds es

    pushad

}

macro restore_ring3_context

{

    popad

    pop    es ds

}

; simply return control to interrupted process

unknown_interrupt:

     iret

macro exc_wo_code [num]

{

  forward

  e#num :

      save_ring3_context

      mov bl, num

      jmp exc_c

}

macro exc_w_code [num]

{

  forward

  e#num :

      add esp, 4

      save_ring3_context

      mov bl, num

      jmp exc_c

}

exc_wo_code 0, 1, 2, 3, 4, 5, 6, 9, 15, 18

exc_w_code 8, 10, 11, 12, 13, 14, 17

exc_c:

        mov   ax, os_data

        mov   ds, ax

        mov   es, ax

; test if debugging

        cli

        mov   eax, [0x3000]

        shl   eax, 8

        mov   eax, [0x80000+eax+APPDATA.debugger_slot]

        test  eax, eax

        jnz   .debug

        sti

; not debuggee => say error and terminate

        add   esp, 28h

        movzx eax, bl

        mov   [error_interrupt], eax

        call  show_error_parameters

        mov   edx, [0x3010]

        mov   [edx + TASKDATA.state], byte 4

        jmp   change_task

.debug:

; we are debugged process, notify debugger and suspend ourself

; eax=debugger PID

        cld

        movzx ecx, bl

        push  ecx

        mov   ecx, [0x3010]

        push  dword [ecx+TASKDATA.pid]    ; PID of current process

        push  12

        pop   ecx

        push  1        ; 1=exception

        call  debugger_notify

        pop   ecx

        pop   ecx

        pop   ecx

        mov   edx, [0x3010]

        mov   byte [edx+TASKDATA.state], 1        ; suspended

        call  change_task

        restore_ring3_context

        iretd

;;;;;;;;;;;;;;;;;;;;;;;

;; FPU ERROR HANDLER ;;

;;;;;;;;;;;;;;;;;;;;;;;

align 4

e7:

        save_ring3_context

        clts

        mov ax, os_data

        mov ds, ax

        mov es, ax

        mov ebx, [fpu_owner]

        cmp ebx, [CURRENT_TASK]

        je .exit

        shl ebx, 8

        mov eax, [ebx+PROC_BASE+APPDATA.fpu_state]

        bt [cpu_caps], CAPS_FXSR

        jnc .no_SSE

        fxsave [eax]

        mov ebx, [CURRENT_TASK]

        mov [fpu_owner], ebx

        shl ebx, 8

        cmp dword [ebx+PROC_BASE+APPDATA.fpu_init], 0

        je .init

        mov eax, [ebx+PROC_BASE+APPDATA.fpu_state]

        fxrstor [eax]

        restore_ring3_context

        iret

.no_SSE:

        fnsave [eax]

        mov ebx, [CURRENT_TASK]

        mov [fpu_owner], ebx

        shl ebx, 8

        cmp dword [ebx+PROC_BASE+APPDATA.fpu_init], 0

        je .ready

        mov eax, [ebx+PROC_BASE+APPDATA.fpu_state]

        frstor [eax]

        restore_ring3_context

        iret

.init:

        fninit                      ;­ ¬ ­¥ ­ã¦­ë ­¥¬ áª¨à®¢ ­­ë¥ ¨áª«î祭¨ï

.ready:

        mov dword [ebx+PROC_BASE+APPDATA.fpu_init], 1

.exit:

        restore_ring3_context

        iret

iglobal

  fpu_owner dd 1

 endg

writehex:

      pusha

      mov  edi, [write_error_to]

      mov  esi, 8

    @@:

      mov  ecx, eax

      and  ecx, 0xf

      mov  cl,[ecx+hexletters]

      mov  [edi],cl

      dec  edi

      shr  eax,4

      dec  esi

      jnz  @b

      popa

      ret

iglobal

  hexletters  db '0123456789ABCDEF'

  error_interrupt         dd  -1

  process_error  db 'K : Process - forced terminate INT: 00000000',13,10,0

  process_pid    db 'K : Process - forced terminate PID: 00000000',13,10,0

  process_eip    db 'K : Process - forced terminate EIP: 00000000',13,10,0

  system_error   db 'K : Kernel error',13,10,0

endg

uglobal

  write_error_to  dd  0x0

endg

show_error_parameters:

        mov    [write_error_to],process_pid+43

        mov    eax,[0x3000]

        shl    eax, 5

        mov    eax,[0x3000+TASKDATA.pid+eax]

        call   writehex

        mov    [write_error_to],process_error+43

        mov    eax,[error_interrupt]

        call   writehex

        cmp    dword [esp+4+4], os_code ; CS

        jnz    @f

        mov    esi,system_error

        call   sys_msg_board_str

      @@:

        mov    eax, [esp+4] ; EIP

        mov    [write_error_to],process_eip+43

        call   writehex

        mov    esi,process_error

        call   sys_msg_board_str

        mov    esi,process_pid

        call   sys_msg_board_str

        mov    esi,process_eip

        call   sys_msg_board_str

        ret

; irq1  ->  hid/keyboard.inc

macro irqh [num]

{

  forward

  p_irq#num :

     save_ring3_context

     mov   edi, num

     jmp   irq_c

}

irqh 2,5,7,8,9,10,11

 irq_c:

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     call  irqhandler

     restore_ring3_context

     iret

p_irq6:

     save_ring3_context

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     call  fdc_irq

     call  ready_for_next_irq

     restore_ring3_context

     iret

p_irq3:

     save_ring3_context

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     cmp   [com2_mouse_detected],0

     je    old_irq3_handler

     call  check_mouse_data_com2

     jmp   p_irq3_1

 old_irq3_handler:

     mov   edi,3

     call  irqhandler

  p_irq3_1:

     restore_ring3_context

     iret

p_irq4:

     save_ring3_context

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     cmp   [com1_mouse_detected],0

     je    old_irq4_handler

     call  check_mouse_data_com1

     jmp   p_irq4_1

 old_irq4_handler:

     mov   edi,4

     call  irqhandler

  p_irq4_1:

     restore_ring3_context

     iret

p_irq12:

     save_ring3_context

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     call  check_mouse_data_ps2

     restore_ring3_context

     iret

p_irq14:

        save_ring3_context

        mov     ax, os_data

        mov     ds, ax

        mov     es, ax

        call    [irq14_func]

        call    ready_for_next_irq_1

        restore_ring3_context

        iret

p_irq15:

        save_ring3_context

        mov     ax, os_data

        mov     ds, ax

        mov     es, ax

        call    [irq15_func]

        call    ready_for_next_irq_1

        restore_ring3_context

        iret

ready_for_next_irq:

     mov    [check_idle_semaphore],5

     mov   al, 0x20

     out   0x20, al

     ret

ready_for_next_irq_1:

     mov    [check_idle_semaphore],5

     mov   al, 0x20

     out    0xa0,al

     out   0x20, al

     ret

irqD:

     save_ring3_context

     mov   ax, os_data

     mov   ds, ax

     mov   es, ax

     mov   dx,0xf0

     mov   al,0

     out   dx,al

     mov   dx,0xa0

     mov   al,0x20

     out   dx,al

     mov   dx,0x20

     out   dx,al

     restore_ring3_context

     iret

irqhandler:

     push   edi

     mov    esi,edi          ; 1

     shl    esi,6            ; 1

     add    esi,irq00read    ; 1

     shl    edi,12           ; 1

     add    edi,0x2E0000

     mov    ecx,16

     mov    [check_idle_semaphore],5

   irqnewread:

     dec    ecx

     js     irqover

     mov    dx,[esi]         ; 2+

     cmp    dx,0             ; 1

     jz     irqover

     cmp    [esi+3],byte 1   ; 2     ; byte read

     jne    noirqbyte        ; 4-11

     in     al,dx

     mov    edx,[edi]

     cmp    edx,4000

     je     irqfull

     mov    ebx,edi

     add    ebx,0x10

     add    ebx,edx

     mov    [ebx],al

     inc    edx

     mov    [edi],edx

     add    esi,4

     jmp    irqnewread

   noirqbyte:

     cmp    [esi+3],byte 2     ; word read

     jne    noirqword

     in     ax,dx

     mov    edx,[edi]

     cmp    edx,4000

     je     irqfull

     mov    ebx,edi

     add    ebx,0x10

     add    ebx,edx

     mov    [ebx],ax

     add    edx,2

     mov    [edi],edx

     add    esi,4

     jmp    irqnewread

   noirqword:

   irqfull:

   irqover:

     mov    al,0x20            ; ready for next irq

     out    0x20,al

     pop    ebx

     cmp    ebx,7

     jbe    noa0

     out    0xa0,al

   noa0:

     ret

set_application_table_status:

        push eax

        mov  eax,[0x3000]

        shl  eax, 5

        add  eax,0x3000+TASKDATA.pid

        mov  eax,[eax]

        mov  [application_table_status],eax

        pop  eax

        ret

clear_application_table_status:

        push eax

        mov  eax,[0x3000]

        shl  eax, 5

        add  eax,0x3000+TASKDATA.pid

        mov  eax,[eax]

        cmp  eax,[application_table_status]

        jne  apptsl1

        mov  [application_table_status],0

      apptsl1:

        pop  eax

        ret

sys_resize_app_memory:

        ; eax = 1 - resize

        ;     ebx = new amount of memory

        cmp    eax,1

        jne    .no_application_mem_resize

        stdcall new_mem_resize, ebx

        mov [esp+36], eax

        ret

.no_application_mem_resize:

        ret

get_app_params:

    push eax

    cmp  [0x90000+6],word '00'

    jne  no_00_header

    mov  eax,[0x90000+12]

    mov  [app_start],eax

    mov  eax,[0x90000+16]

    mov  [app_i_end],eax

    mov  eax,[0x90000+20]

    mov  [app_mem],eax

; \begin{diamond}[20.08.2006]

; sanity check (functions 19,58 load app_i_end bytes and that must

; fit in allocated memory to prevent kernel faults)

    cmp  eax,[app_i_end]

    jb   no_01_header

; \end{diamond}[20.08.2006]

    shr  eax,1

    sub  eax,0x10

    mov  [app_esp],eax

    mov  eax,[0x90000+24]

    mov  [app_i_param],eax

    mov  [app_i_icon],dword 0

    pop  eax

    clc

    ret

  no_00_header:

    cmp  [0x90000+6],word '01'

    jne  no_01_header

    mov  eax,[0x90000+12]

    mov  [app_start],eax

    mov  eax,[0x90000+16]

    mov  [app_i_end],eax

    mov  eax,[0x90000+20]

    mov  [app_mem],eax

; \begin{diamond}[20.08.2006]

    cmp  eax,[app_i_end]

    jb   no_01_header

; \end{diamond}[20.08.2006]

    mov  eax,[0x90000+24]

    mov  [app_esp],eax

    mov  eax,[0x90000+28]

    mov  [app_i_param],eax

    mov  eax,[0x90000+32]

    mov  [app_i_icon],eax

    pop  eax

    clc

    ret

   no_01_header:

    pop  eax

    stc

    ret

uglobal

  new_process_place  dd  0x0

  app_start    dd  0x0

  app_i_end    dd  0x0

  app_mem      dd  0x0

  app_esp      dd  0x0

  app_i_param  dd  0x0

  app_i_icon   dd  0x0

;  app_mem_pos  dd  0x0

  appl_path        dd 0x0

  appl_path_size   dd 0x0

endg

sys_threads:

; eax=1 create thread

;

;   ebx=thread start

;   ecx=thread stack value

;

; on return : eax = pid

jmp new_sys_threads

iglobal

  process_terminating   db 'K : Process - terminating',13,10,0

  process_terminated    db 'K : Process - done',13,10,0

endg

terminate: ; terminate application

    push   esi

    mov    esi,process_terminating

    call   sys_msg_board_str

    pop    esi

@@:

    cli

    cmp   [application_table_status],0

    je    term9

    sti

    call  change_task

    jmp   @b

  term9:

    call  set_application_table_status

    mov    eax,esi

    pushad

    shl   eax,8

    mov   eax,[PROC_BASE+eax+0xB8]

    stdcall destroy_app_space, eax

    popad

    cmp   [fpu_owner],esi   ; if user fpu last -> fpu user = 1

    jne   fpu_ok_1

    mov   [fpu_owner],1

  fpu_ok_1:

    mov   [0xf400],byte 0           ; empty keyboard buffer

    mov   [0xf500],byte 0           ; empty button buffer

; remove defined hotkeys

        mov     eax, hotkey_list

.loop:

        cmp     [eax+8], esi

        jnz     .cont

        mov     ecx, [eax]

        jecxz   @f

        push    dword [eax+12]

        pop     dword [ecx+12]

@@:

        mov     ecx, [eax+12]

        push    dword [eax]

        pop     dword [ecx]

        xor     ecx, ecx

        mov     [eax], ecx

        mov     [eax+4], ecx

        mov     [eax+8], ecx

        mov     [eax+12], ecx

.cont:

        add     eax, 16

        cmp     eax, hotkey_list+256*16

        jb      .loop

; remove hotkeys in buffer

        mov     eax, hotkey_buffer

.loop2:

        cmp     [eax], esi

        jnz     .cont2

        and     dword [eax+4], 0

        and     dword [eax], 0

.cont2:

        add     eax, 8

        cmp     eax, hotkey_buffer+120*8

        jb      .loop2

    mov   ecx,esi                 ; remove buttons

  bnewba2:

    mov   edi,[0xfe88]

    mov   eax,edi

    cld

    movzx ebx,word [edi]

    inc   bx

  bnewba:

    dec   bx

    jz    bnmba

    add   eax,0x10

    cmp   cx,[eax]

    jnz   bnewba

    pusha

    mov   ecx,ebx

    inc   ecx

    shl   ecx,4

    mov   ebx,eax

    add   eax,0x10

    call  memmove

    dec   dword [edi]

    popa

    jmp   bnewba2

  bnmba:

    pusha     ; save window coordinates for window restoring

    cld

    shl   esi,5

    add   esi,window_data

    mov   eax,[esi+WDATA.box.left]

    mov   [dlx],eax

    add   eax,[esi+WDATA.box.width]

    mov   [dlxe],eax

    mov   eax,[esi+WDATA.box.top]

    mov   [dly],eax

    add   eax,[esi+WDATA.box.height]

    mov   [dlye],eax

    xor   eax, eax

    mov   [esi+WDATA.box.left],eax

    mov   [esi+WDATA.box.width],eax

    mov   [esi+WDATA.box.top],eax

    mov   [esi+WDATA.box.height],eax

    mov   [esi+WDATA.cl_workarea],eax

    mov   [esi+WDATA.cl_titlebar],eax

    mov   [esi+WDATA.cl_frames],eax

    mov   dword [esi+WDATA.reserved],eax ; clear all flags: wstate, redraw, wdrawn

    lea   edi, [esi-window_data+draw_data]

    mov   ecx,32/4

    rep   stosd

    popa

; debuggee test

    pushad

    mov  edi, esi

    shl  edi, 5

    mov  eax, [0x80000+edi*8+APPDATA.debugger_slot]

    test eax, eax

    jz   .nodebug

    push 8

    pop  ecx

    push dword [0x3000+edi+TASKDATA.pid]   ; PID

    push 2

    call debugger_notify

    pop  ecx

    pop  ecx

.nodebug:

    popad

    pusha         ; at 0x80000+

    mov   edi,esi

    shl   edi,8

    add   edi,0x80000

    mov   ecx,256/4

    xor   eax, eax

    rep   stosd

    popa

    pusha          ; name to spaces

    mov   edi,esi

    shl   edi,8

    add   edi,0x80000+APPDATA.app_name

    mov   ecx,11

    mov   eax,' '

    rep   stosb

    popa

  ; activate window

        movzx  eax, word [0xC000 + esi*2]

        cmp    eax, [0x3004]

        jne    .dont_activate

        pushad

 .check_next_window:

        dec    eax

        cmp    eax, 1

        jbe    .nothing_to_activate

        lea    esi, [0xc400+eax*2]

        movzx  edi, word [esi]               ; edi = process

        shl    edi, 5

        cmp    [0x3000 + edi + TASKDATA.state], byte 9  ; skip dead slots

        je     .check_next_window

        add    edi, window_data

; \begin{diamond}[19.09.2006]

; skip minimized windows

        test   [edi + WDATA.fl_wstate], WSTATE_MINIMIZED

        jnz    .check_next_window

; \end{diamond}

        call   waredraw

 .nothing_to_activate:

        popad

 .dont_activate:

        push    esi     ; remove hd1 & cd & flp reservation

        shl     esi, 5

        mov     esi, [esi+0x3000+TASKDATA.pid]

        cmp     [hd1_status], esi

        jnz     @f

        mov     [hd1_status], 0

@@:

        cmp     [cd_status], esi

        jnz     @f

        mov     [cd_status], 0

@@:

        cmp     [flp_status], esi

        jnz     @f

        mov     [flp_status], 0

@@:

        pop     esi

    pusha ; remove all irq reservations

    mov   eax,esi

    shl   eax, 5

    mov   eax,[eax+0x3000+TASKDATA.pid]

    mov   edi,irq_owner

    mov   ecx,16

  newirqfree:

    scasd

    jne   nofreeirq

    mov   [edi-4],dword 0

  nofreeirq:

    loop   newirqfree

    popa

    pusha                     ; remove all port reservations

    mov   edx,esi

    shl   edx, 5

    add   edx,0x3000

    mov   edx,[edx+TASKDATA.pid]

  rmpr0:

    mov   esi,[0x2d0000]

    cmp   esi,0

    je    rmpr9

  rmpr3:

    mov   edi,esi

    shl   edi,4

    add   edi,0x2d0000

    cmp   edx,[edi]

    je    rmpr4

    dec   esi

    jnz   rmpr3

    jmp   rmpr9

  rmpr4:

    mov   ecx,256

    sub   ecx,esi

    shl   ecx,4

    mov   esi,edi

    add   esi,16

    cld

    rep   movsb

    dec   dword [0x2d0000]

    jmp   rmpr0

  rmpr9:

    popa

    mov  edi,esi         ; do not run this process slot

    shl  edi, 5

    mov  [edi+0x3000 + TASKDATA.state],byte 9

; debugger test - terminate all debuggees

    mov  eax, 2

    mov  ecx, 0x80000+2*0x100+APPDATA.debugger_slot

.xd0:

    cmp  eax, [0x3004]

    ja   .xd1

    cmp  dword [ecx], esi

    jnz  @f

    and  dword [ecx], 0

    pushad

    xchg eax, ebx

    mov  eax, 2

    call sys_system

    popad

@@:

    inc  eax

    add  ecx, 0x100

    jmp  .xd0

.xd1:

;    call  systest

    sti  ; .. and life goes on

    mov   eax, [dlx]

    mov   ebx, [dly]

    mov   ecx, [dlxe]

    mov   edx, [dlye]

    call  calculatescreen

    xor   eax, eax

    xor   esi, esi

    call  redrawscreen

    mov   [0xfff4],byte 0  ; no mouse background

    mov   [0xfff5],byte 0  ; draw mouse

    mov   [application_table_status],0

    mov   esi,process_terminated

    call  sys_msg_board_str

    ret

iglobal

  boot_sched_1    db   'Building gdt tss pointer',0

  boot_sched_2    db   'Building IDT table',0

endg

build_scheduler:

        mov    esi,boot_sched_1

        call   boot_log

        call   build_process_gdt_tss_pointer

        mov    esi,boot_sched_2

        call   boot_log

        call   build_interrupt_table

        ret