.386p
locals

_DATA           segment dword public use32 'DATA'
_DATA           ends
_BSS            segment dword public use32 'BSS'
_BSS            ends

DGROUP          group   _DATA, _BSS
assume  cs:_TEXT, ds:DGROUP

extrn   __lowbufptr:dword
extrn   _envsel:word

public  GETENV

_TEXT           segment byte public use32 'CODE'
assume  cs:_TEXT, ds:DGROUP

GETENV:
        push esi edi
        cld

        mov edi,[esp+4+8+00h]
        or ecx,-1
        xor al,al
        repne scasb
        not ecx
        lea edx,[ecx-1]
        
        mov es,_envsel
        xor edi,edi

@@00l:
        mov esi,[esp+4+8+00h]
        mov ecx,edx
        repe cmpsb
        jne short @@00l00

        mov al,'='
        scasb
        jne short @@00l00

        mov esi,edi
        or ecx,-1
        xor al,al
        repne scasb
        not ecx

        mov edi,__lowbufptr
        mov ax,es
        mov dx,ds
        mov ds,ax
        mov es,dx
        mov eax,edi

        mov dl,cl
        shr ecx,2
        rep movsd
        mov cl,dl
        and cl,3
        rep movsb

        mov cx,es
        mov ds,cx
        jmp short @@00

@@00l00:
        or ecx,-1
        xor al,al
        repne scasb
        cmp es:[edi],al
        jne @@00l

        mov ax,ds
        mov es,ax
        xor eax,eax

@@00:
        pop edi esi
        ret 04h

_TEXT           ends
end