diff options
Diffstat (limited to 'engines/cge/ems.cpp')
| -rw-r--r-- | engines/cge/ems.cpp | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/engines/cge/ems.cpp b/engines/cge/ems.cpp new file mode 100644 index 0000000000..56d853f4e8 --- /dev/null +++ b/engines/cge/ems.cpp @@ -0,0 +1,225 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +/* + * This code is based on original Soltys source code + * Copyright (c) 1994-1995 Janus B. Wisniewski and L.K. Avalon + */ + +#include "cge/general.h" + +namespace CGE { + +#define EMS_INT 0x67 +#define PAGE_MASK 0x3FFF +#define SIZ(n) ((n) ? ((long)n) : (0x10000L)) + + +enum EMM_FUN { + GET_STATUS = 0x40, GET_FRAME, GET_SIZE, OPEN_HANDLE, MAP_PAGE, + CLOSE_HANDLE, GET_VER, SAVE_CONTEXT, REST_CONTEXT, GET_PAGES = 0x4B, + GET_HANDLES, GET_INFO, CONTROL +}; + + +void *EMM::Frame = NULL; + + +EMM::EMM(long size): Han(-1), Top(0), Lim(0), List(NULL) { + /* + if (Test()) + { + asm mov ah,GET_FRAME // get EMS frame segment + asm int EMS_INT // do it! + asm or ah,ah // see status + asm jnz xit // abort on error + Frame = (void _seg *) _BX; // save frame segment + + if (size == 0) + { + asm mov ah,GET_SIZE // get EMS memory size + asm int EMS_INT // do it! + asm or ah,ah // see status + asm jnz xit // abort on error + asm or bx,bx // test page count + asm jz xit // abort if no free pages + // number of available pages in BX is ready to use by OPEN + } + else _BX = (uint16) ((size + PAGE_MASK) >> 14); + asm mov ah,OPEN_HANDLE // open EMM handle + asm int EMS_INT // do it! + asm or ah,ah // see status + asm jnz xit // abort on error + Han = _DX; + Lim = _BX; + Lim <<= 14; + _DX = Han; + asm mov ah,SAVE_CONTEXT // save mapping context + asm int EMS_INT // do it! + } + xit: + */ + warning("STUB: EMM:EMM"); +} + + +EMM::~EMM(void) { + /* FIXME + Release(); + if (Han >= 0) + { + _DX = Han; + asm mov ah,REST_CONTEXT + asm int EMS_INT + asm mov ah,CLOSE_HANDLE + asm int EMS_INT + } + */ +} + + +bool EMM::Test(void) { + /* + static char e[] = "EMMXXXX0"; + + asm mov ax,0x3D40 + asm mov dx,offset e + asm int 0x21 + asm jc fail + + asm push ax + asm mov bx,ax + asm mov ax,0x4407 + asm int 0x21 + + asm pop bx + asm push ax + asm mov ax,0x3E00 + asm int 0x21 + asm pop ax + + asm cmp al,0x00 + asm je fail + + success: + return TRUE; + fail: + return FALSE; + */ + warning("EMM::Test"); + return false; +} + + +EMS *EMM::Alloc(uint16 siz) { + /* + long size = SIZ(siz), + top = Top; + + uint16 pgn = (uint16) (top >> 14), + cnt = (uint16) ((top + size + PAGE_MASK) >> 14) - pgn; + + if (cnt > 4) + { + top = (top + PAGE_MASK) & 0xFFFFC000L; + pgn++; + cnt--; + } + + if (size <= Lim - top) + { + EMS * e = new EMS, * f; + + if (e) + { + Top = (e->Ptr = top) + (e->Siz = siz); + e->Emm = this; + + if (List) + { + for (f = List; f->Nxt; f = f->Nxt); + return (f->Nxt = e); // existing list: link to the end + } + else + { + return (List = e); // empty list: link to the head + } + } + } + fail: return NULL; + */ + warning("STUB: EMM::Alloc"); + return NULL; +} + + +void EMM::Release(void) { + while (List) { + EMS *e = List; + List = e->Nxt; + delete e; + } + Top = 0; +} + + +EMS::EMS(void) : Ptr(0), Siz(0), Nxt(NULL) { +} + + +void *EMS::operator & () const { + /* + uint16 pgn = (uint16) (Ptr >> 14), + off = (uint16) Ptr & PAGE_MASK, + cnt = (uint16) ((Ptr + SIZ(Siz) + PAGE_MASK) >> 14) - pgn, + cmd = MAP_PAGE << 8; + + _DX = Emm->Han; // take EMM handle + asm dec cnt // prapare for deferred checking + asm or dx,dx // see if valid + asm jns more // negative handle = unavailable + + fail: return NULL; + + more: + asm mov ax,cmd // command + page frame index + asm mov bx,pgn // logical page number + asm int EMS_INT // do it! + asm or ah,ah // check error code + asm jnz fail // exit on error + asm inc cmd // advance page frame index + asm inc pgn // advance logical page number + asm cmp al,byte ptr cnt // all pages? + asm jb more + + return (void *) (EMM::Frame + (void *) off); + */ + warning("STUB: EMS::operator &"); + return NULL; +} + + +uint16 EMS::Size(void) { + return Siz; +} + +} // End of namespace CGE |