Subversion Repositories Kolibri OS

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

; load one or more DLL file in COFF format and try to import functions by our list

; if first function in import list begins with 'lib_', call it as DLL initialization

; return eax = 1 as fail, if anyone of .obj file not found in /sys/lib

; return 0 if all fine, but 0 not garantees in succesfull import - see dll.Link comment

; dirties all registers! eax, ebx, ecx, edx, esi, edi

proc dll.Load, import_table:dword

        mov     esi, [import_table]

  .next_lib:

        mov     edx, [esi]

        or      edx, edx

        jz      .exit

        push    esi

        mov     esi, [esi + 4]

        mov     edi, esi

        cmp     byte[esi], '/'

        jz      .load_lib

        mov     edi, s_libdir.fname

    @@:

        lodsb

        stosb

        or      al, al

        jnz     @b

        mov     edi, s_libdir

  .load_lib:

        mcall   68, 19, edi ;s_libdir

        or      eax, eax

        jz      .fail

        stdcall dll.Link, eax, edx

        push    eax

        mov     eax, [eax]

        cmp     dword[eax], 'lib_'

        pop     eax

        jnz     @f

        stdcall dll.Init, [eax + 4]

    @@:

        pop     esi

        add     esi, 8

        jmp     .next_lib

  .exit:

        xor     eax, eax

        ret

  .fail:

        add     esp, 4

        xor     eax, eax

        inc     eax

        ret

endp

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

; scans dll export table for a functions we want to import

; break scan on first unresolved import

; no return value

proc dll.Link, exp:dword, imp:dword

        push    eax

        mov     esi, [imp]

        test    esi, esi

        jz      .done

  .next:

        lodsd

        test    eax, eax

        jz      .done

        stdcall dll.GetProcAddress, [exp], eax

        or      eax, eax

        jz      @f

        mov     [esi - 4], eax

        jmp     .next

    @@:

        mov     dword[esp], 0

  .done:

        pop     eax

        ret

endp

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

; calls lib_init with predefined parameters

; no return value

proc dll.Init, dllentry:dword

        pushad

        mov     eax, mem.Alloc

        mov     ebx, mem.Free

        mov     ecx, mem.ReAlloc

        mov     edx, dll.Load

        stdcall [dllentry]

        popad

        ret

endp

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

; scans export table for a sz_name function

; returns in eax function address or 0 if not found

proc dll.GetProcAddress, exp:dword, sz_name:dword

        mov     edx, [exp]

        xor     eax, eax

  .next:

        or      edx, edx

        jz      .end

        cmp     dword[edx], 0

        jz      .end

        stdcall strcmp, [edx], [sz_name]

        test    eax, eax

        jz      .ok

        add     edx, 8

        jmp     .next

  .ok:

        mov     eax, [edx + 4]

  .end:

        cmp eax, -1

        jnz @f

        xor eax, eax

  @@:

        ret

endp

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

; compares strings

; returns eax = 0 if equal, -1 otherwise

proc strcmp, str1:dword, str2:dword

        push    esi edi

        mov     esi, [str1]

        mov     edi, [str2]

        xor     eax, eax

    @@:

        lodsb

        scasb

        jne     .fail

        or      al, al

        jnz     @b

        jmp     .ok

  .fail:

        or      eax, -1

  .ok:

        pop     edi esi

        ret

endp

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

if defined dll.Load

s_libdir:

  db '/sys/lib/'

  .fname rb 32

end if

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

proc mem.Alloc, size

        push    ebx ecx

        mov     ecx, [size]

        mcall   68, 12

        pop     ecx ebx

        ret

endp

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

proc mem.ReAlloc, mptr, size

        push    ebx ecx edx

        mov     ecx, [size]

        mov     edx, [mptr]

        mcall   68, 20

        pop     edx ecx ebx

        ret

endp

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

proc mem.Free, mptr

        push    ebx ecx

        mov     ecx,[mptr]

        mcall   68, 13

        pop     ecx ebx

        ret

endp

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