include 'proc32.inc'

DLL_ENTRY equ 1
DLL_EXIT  equ -1
REQ_DLL_VER equ 3

use32
        db      'MENUET01'
        dd      1
        dd      start
        dd      i_end
        dd      mem
        dd      mem
        dd      0
        dd      0

start:
        stdcall load_dll_and_import, dllname, imports
        test    eax, eax
        jz      exit

; check version
        cmp     word [dll_ver], REQ_DLL_VER
        jb      exit
        cmp     word [dll_ver+2], REQ_DLL_VER
        ja      exit
        push    DLL_ENTRY
        call    [dll_start]

; yes! Now do some work (gets() demo in this case).

        push    caption
        push    -1
        push    -1
        push    -1
        push    -1
        call    [con_init]

; C-equivalent of the following code:
; for (;;)
; {
;   con_write_asciiz("Enter string (empty for exit): ");
;   con_gets(s,256);
;   if (s[0] == '\n') break;
;   con_write_asciiz("You entered: ");
;   con_write_asciiz(s);
; }
mainloop:
        push    str1
        call    [con_write_asciiz]
        push    256
        push    s
        call    [con_gets]
        cmp     [s], 10
        jz      done
        push    str2
        call    [con_write_asciiz]
        push    s
        call    [con_write_asciiz]
        jmp     mainloop
done:
        push    1
        call    [con_exit]
exit:
        or      eax, -1
        int     0x40

proc load_dll_and_import stdcall, _dllname:dword, _imports:dword
        pushad
; load DLL
        push    68
        pop     eax
        push    19
        pop     ebx
        mov     ecx, [_dllname]
        int     0x40
        test    eax, eax
        jz      import_fail

; initialize import
        mov     edi, eax
        mov     esi, [_imports]
import_loop:
        lodsd
        test    eax, eax
        jz      import_done
        mov     edx, edi
import_find:
        mov     ebx, [edx]
        test    ebx, ebx
        jz      import_not_found
        push    eax
@@:
        mov     cl, [eax]
        cmp     cl, [ebx]
        jnz     import_find_next
        test    cl, cl
        jz      import_found
        inc     eax
        inc     ebx
        jmp     @b
import_find_next:
        pop     eax
        add     edx, 8
        jmp     import_find
import_found:
        pop     eax
        mov     eax, [edx+4]
        mov     [esi-4], eax
        jmp     import_loop
import_not_found:
import_fail:
        popad
        xor     eax, eax
        ret
import_done:
        popad
        xor     eax, eax
        inc     eax
        ret
endp

align 4

imports:
dll_start          dd szStart
dll_ver            dd szVersion
con_init           dd szcon_init
con_write_asciiz   dd szcon_write_asciiz
con_exit           dd szcon_exit
con_gets           dd szcon_gets
                   dd 0

szStart            db 'START',0
szVersion          db 'version',0
szcon_init         db 'con_init',0
szcon_write_asciiz db 'con_write_asciiz',0
szcon_exit         db 'con_exit',0
szcon_gets         db 'con_gets',0

dllname  db '/sys/lib/console.obj',0

caption            db 'Console test - gets()',0
str1               db 'Enter string (empty for exit): ',0
str2               db 'You entered: ',0

i_end:

s rb 256

align 4
rb 2048 ; stack
mem: