/*- * Copyright (c) 1997 Helmut Wirth * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice immediately at the beginning of the file, witout modification, * this list of conditions, and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include __FBSDID("$FreeBSD: src/usr.bin/doscmd/ems.c,v 1.3.2.2 2002/04/25 11:04:51 tg Exp $"); /* * EMS memory emulation * * To emulate Expanded Memory we use a DOS driver (emsdriv.sys) which * routes calls to int 0x67 to this emulator routine. The main entry point * is ems_entry(..). The emulator needs to be initialized before the first * call. The first step of the initialization is done during program startup * the second part is done during DOS boot, from a call of the DOS driver. * The DOS driver is neccessary because DOS programs look for it to * determine if EMS is available. * * To emulate a configurable amount of EMS memory we use a file created * at startup with the size of the configured EMS memory. This file is * mapped into the EMS window like any DOS memory manager would do, using * mmap calls. * * The emulation follows the LIM EMS 4.0 standard. Not all functions of it * are implemented yet. The "alter page map and jump" and "alter page map * and call" functions are not implemented, because they are rather hard to * do. (It would mean a call to the emulator executes a routine in EMS * memory and returns to the emulator, the emulator switches the page map * and then returns to the DOS program.) LINUX does not emulate this * functions and I think they were very rarely used by DOS applications. * * Credits: To the writers of LINUX dosemu, I looked at their code */ #include #include #include #include #include "doscmd.h" #include "ems.h" /* Will be configurable */ u_long ems_max_size = EMS_MAXSIZE * 1024; u_long ems_frame_addr = EMS_FRAME_ADDR; /* * Method for EMS: Allocate a mapfile with the size of EMS memory * and map the needed part into the page frame */ #define EMS_MAP_PATH "/var/tmp/" /* Use a big file system */ #define EMS_MAP_FILE "doscmd.XXXXXX" static int mapfile_fd = -1; /* Pages are always 16 kB in size. The page frame is 64 kB, there are * 4 positions (0..3) for a page to map in. The pages are numbered from 0 to * the highest 16 kB page in the mapfile, depending on the EMS size */ EMS_mapping_context ems_mapping_context; /* Handle and page management (see ems.h) */ /* The handle array. If the pointer is NULL, the handle is unallocated */ static EMS_handle *ems_handle[EMS_NUM_HANDLES]; static u_long ems_alloc_handles; /* The active handle, if any */ static short active_handle; /* The page array. It is malloced at runtime, depending on the total * allocation size */ static EMS_page *ems_page = NULL; static u_long ems_total_pages; static u_long ems_alloc_pages; static u_long ems_free_pages; /* Local structure used for region copy and move operations */ struct copydesc { #define SRC_EMS 1 #define DST_EMS 2 short copytype; /* Type of source and destination memory */ EMS_addr src_addr; /* Combined pointer for source */ EMS_addr dst_addr; /* Combined pointer for destination */ u_long rest_len; /* Lenght to copy */ }; /* Local prototypes */ static int init_mapfile(void); static void map_page(u_long, u_char, short, int); static EMS_handle *get_new_handle(long); static void context_to_handle(short); static long find_next_free_handle(void); static short lookup_handle(Hname *hp); static void allocate_pages_to_handle(u_short, long); static void allocate_handle(short, long); static void reallocate_pages_to_handle(u_short, long); static void free_handle(short); static void free_pages_of_handle(short); static void restore_context(EMS_mapping_context *); static void save_context_to_dos(EMScontext *); static int check_saved_context(EMScontext *); static void *get_valid_pointer(u_short, u_short, u_long); static u_long move_ems_to_conv(short, u_short, u_short, u_long, u_long); static u_long move_conv_to_ems(u_long, u_short, u_short, u_short, u_long); static u_long move_ems_to_ems(u_short, u_short, u_short, u_short, u_short, u_short, u_long); /* * EMS initialization routine: Return 1, if successful, return 0 if * init problem or EMS disabled */ int ems_init() { unsigned i; if (ems_max_size == 0) return 0; if (init_mapfile() == 0) return 0; /* Sanity */ bzero((void *)(&ems_handle[0]), sizeof(ems_handle)); ems_total_pages = ems_max_size / EMS_PAGESIZE; ems_alloc_pages = 0; ems_free_pages = ems_total_pages; ems_alloc_handles = 0; active_handle = 0; /* Malloc the page array */ ems_page = (EMS_page *)malloc(sizeof(EMS_page) * ems_total_pages); if (ems_page == NULL) { debug(D_ALWAYS, "Could not malloc page array, EMS disabled\n"); ems_frame_addr = 0; ems_max_size = 0; ems_total_pages = 0; return 0; } for (i = 0; i < ems_total_pages; i++) { ems_page[i].handle = 0; ems_page[i].status = EMS_FREE; } debug(D_EMS, "EMS: Emulation init OK.\n"); return 1; } /* Main entry point */ void ems_entry(regcontext_t *REGS) { /* * If EMS is not enabled, the DOS ems.exe module should not have * been loaded. If it is loaded anyway, report software malfunction */ if (ems_max_size == 0) { R_AH = EMS_SW_MALFUNC; debug(D_EMS, "EMS emulation not enabled\n"); return; } switch (R_AH) { case GET_MANAGER_STATUS: debug(D_EMS, "EMS: Get manager status\n"); R_AH = EMS_SUCCESS; break; case GET_PAGE_FRAME_SEGMENT: debug(D_EMS, "EMS: Get page frame segment\n"); R_BX = ems_frame_addr >> 4; R_AH = EMS_SUCCESS; break; case GET_PAGE_COUNTS: R_BX = ems_total_pages - ems_alloc_pages; R_DX = ems_total_pages; debug(D_EMS, "EMS: Get page count: Returned total=%d, free=%d\n", R_DX, R_BX); R_AH = EMS_SUCCESS; break; case GET_HANDLE_AND_ALLOCATE: { u_short npages; short handle; npages = R_BX; debug(D_EMS, "EMS: Get handle and allocate %d pages: ", npages); /* Enough handles? */ if ((handle = find_next_free_handle()) < 0) { debug(D_EMS,"Return error:No handles\n"); R_AH = EMS_OUT_OF_HANDLES; break; } /* Enough memory for this request ? */ if (npages > ems_free_pages) { debug(D_EMS,"Return error:Request too big\n"); R_AH = EMS_OUT_OF_LOG; break; } if (npages > ems_total_pages) { debug(D_EMS,"Return error:Request too big\n"); R_AH = EMS_OUT_OF_PHYS; break; } /* Not allowed to allocate zero pages with this function */ if (npages == 0) { debug(D_EMS,"Return error:Cannot allocate 0 pages\n"); R_AH = EMS_ZERO_PAGES; break; } /* Allocate the handle */ allocate_handle(handle, npages); /* Allocate the pages */ allocate_pages_to_handle(handle, npages); R_DX = handle; R_AH = EMS_SUCCESS; debug(D_EMS,"Return success:Handle = %d\n", handle); break; } case MAP_UNMAP: { u_char position; u_short hpagenum, spagenum; short handle; debug(D_EMS, "EMS: Map/Unmap handle=%d, pos=%d, pagenum=%d ", R_DX, R_AL, R_BX); handle = R_DX; position = R_AL; if (position > 3) { debug(D_EMS, "invalid position\n"); R_AH = EMS_ILL_PHYS; break; } hpagenum = R_BX; /* This succeeds without a valid handle ! */ if (hpagenum == 0xffff) { /* Unmap only */ map_page(0, position, handle, 1); debug(D_EMS, "(unmap only) success\n"); R_AH = EMS_SUCCESS; break; } if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; debug(D_EMS, "invalid handle\n"); break; } if (hpagenum >= ems_handle[handle]->npages) { R_AH = EMS_LOGPAGE_TOOBIG; debug(D_EMS, "invalid pagenumber\n"); break; } spagenum = ems_handle[handle]->pagenum[hpagenum]; map_page(spagenum, position, handle, 0); debug(D_EMS, "success\n"); R_AH = EMS_SUCCESS; break; } case DEALLOCATE_HANDLE: { short handle; /* Handle valid ? */ handle = R_DX; debug(D_EMS, "EMS: Deallocate handle %d\n", handle); if (handle > 255 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; break; } /* Mapping context saved ? */ if (ems_handle[handle]->mcontext != NULL) { R_AH = EMS_SAVED_MAP; break; } free_pages_of_handle(handle); free_handle(handle); R_AH = EMS_SUCCESS; break; } case GET_EMM_VERSION: debug(D_EMS, "EMS: Get version\n"); R_AL = EMS_VERSION; R_AH = EMS_SUCCESS; break; case SAVE_PAGE_MAP: { short handle; debug(D_EMS, "EMS: Save page map\n"); handle = R_DX; if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; break; } if (ems_handle[handle]->mcontext != NULL) { /* There is already a context saved */ if (memcmp((void *)ems_handle[handle]->mcontext, (void *)&ems_mapping_context, sizeof(EMS_mapping_context)) == 0) R_AH = EMS_ALREADY_SAVED; else R_AH = EMS_NO_ROOM_TO_SAVE; break; } context_to_handle(handle); R_AH = EMS_SUCCESS; break; } case RESTORE_PAGE_MAP: { short handle; debug(D_EMS, "EMS: Restore page map\n"); handle = R_DX; if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; break; } if (ems_handle[handle]->mcontext == NULL) { R_AH = EMS_NO_SAVED_CONTEXT; break; } restore_context(ems_handle[handle]->mcontext); free((void *)ems_handle[handle]->mcontext); ems_handle[handle]->mcontext = NULL; R_AH = EMS_SUCCESS; break; } case RESERVED_1: case RESERVED_2: debug(D_ALWAYS, "Reserved function called: %02x\n", R_AH); R_AH = EMS_FUNC_NOSUP; break; case GET_HANDLE_COUNT: debug(D_EMS, "EMS: Get handle count\n"); R_BX = ems_alloc_handles + 1; R_AH = EMS_SUCCESS; break; case GET_PAGES_OWNED: { short handle; debug(D_EMS, "EMS: Get pages owned\n"); /* Handle valid ? */ handle = R_DX; if (handle > 255 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; break; } if (handle == 0) R_BX = 0; else R_BX = ems_handle[handle]->npages; R_AH = EMS_SUCCESS; break; } case GET_PAGES_FOR_ALL: { EMShandlepage *ehp; unsigned safecount; int i; debug(D_EMS, "EMS: Get pages for all\n"); /* Get the address passed from DOS app */ ehp = (EMShandlepage *)get_valid_pointer(R_ES, R_DI, sizeof(EMShandlepage) * ems_alloc_handles); if (ehp == NULL) { R_AH = EMS_SW_MALFUNC; break; } R_BX = ems_alloc_handles; safecount = 0; for (i = 0; i < 255; i++) { if (ems_handle[i] != NULL) { if (safecount > (ems_alloc_handles+1)) fatal("EMS: ems_alloc_handles is wrong, " "cannot continue\n"); ehp->handle = i; ehp->npages = ems_handle[i]->npages; ehp++; safecount++; } } R_AH = EMS_SUCCESS; break; } case PAGE_MAP: /* This function is a nuisance. It was invented to save time and * memory, but in our case it is useless. We have to support it * but we use the same save memory as for the page map function. * It uses only 20 bytes anyway. We store/restore the entire mapping */ case PAGE_MAP_PARTIAL: { int subfunction; EMScontext *src, *dest; debug(D_EMS, "EMS: Page map "); subfunction = R_AL; if (R_AH == PAGE_MAP_PARTIAL) { debug(D_EMS, "partial "); /* Page map partial has slightly different subfunctions * GET_SET does not exist and is GET_SIZE in this case */ if (subfunction == GET_SET) subfunction = GET_SIZE; } switch (subfunction) { case GET: { debug(D_EMS, "get\n"); /* Get the address passed from DOS app */ dest = (EMScontext *)get_valid_pointer(R_ES, R_DI, sizeof(EMScontext)); if (dest == NULL) { R_AH = EMS_SW_MALFUNC; break; } save_context_to_dos(dest); R_AH = EMS_SUCCESS; break; } case SET: { debug(D_EMS, "set\n"); src = (EMScontext *)get_valid_pointer(R_DS, R_SI, sizeof(EMScontext)); if (src == NULL) { R_AH = EMS_SW_MALFUNC; break; } if (check_saved_context(src) == 0) { R_AH = EMS_SAVED_CONTEXT_BAD; break; } restore_context(&src->ems_saved_context); R_AH = EMS_SUCCESS; break; } case GET_SET: { debug(D_EMS, "get/set\n"); dest = (EMScontext *)get_valid_pointer(R_ES, R_DI, sizeof(EMScontext)); if (dest == NULL) { R_AH = EMS_SW_MALFUNC; break; } save_context_to_dos(dest); src = (EMScontext *)get_valid_pointer(R_DS, R_SI, sizeof(EMScontext)); if (src == NULL) { R_AH = EMS_SW_MALFUNC; break; } if (check_saved_context(src) == 0) { R_AH = EMS_SAVED_CONTEXT_BAD; break; } restore_context(&src->ems_saved_context); R_AH = EMS_SUCCESS; break; } case GET_SIZE: debug(D_EMS, "get size\n"); R_AL = (sizeof(EMScontext) + 1) & 0xfe; R_AH = EMS_SUCCESS; break; default: debug(D_EMS, "invalid subfunction\n"); R_AH = EMS_INVALID_SUB; break; } break; } case MAP_UNMAP_MULTI_HANDLE: { u_char position; u_short hpagenum, spagenum; short handle; EMSmapunmap *mp; int n_entry, i; debug(D_EMS, "EMS: Map/Unmap multiple "); if ((n_entry = R_CX) > 3) { R_AH = EMS_ILL_PHYS; } /* This is valid according to the LIM EMS 4.0 spec */ if (n_entry == 0) { R_AH = EMS_SUCCESS; break; } handle = R_DX; if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; break; } mp = (EMSmapunmap *)get_valid_pointer(R_DS, R_SI, sizeof(EMSmapunmap) * n_entry); if (mp == NULL) { R_AH = EMS_SW_MALFUNC; break; } R_AH = EMS_SUCCESS; /* Walk through the table and map/unmap */ for (i = 0; i < n_entry; i++) { hpagenum = mp->log; /* Method is in R_AL */ if (R_AL == 0) { debug(D_EMS, "phys page method\n"); if (mp->phys <= 3) { position = mp->phys; } else { R_AH = EMS_ILL_PHYS; break; } } else if (R_AL == 1) { /* Compute position from segment address */ u_short p_seg; debug(D_EMS, "segment method\n"); p_seg = mp->phys; p_seg -= ems_frame_addr; p_seg /= EMS_PAGESIZE; if (p_seg <= 3) { position = p_seg; } else { R_AH = EMS_ILL_PHYS; break; } } else { debug(D_EMS, "invalid subfunction\n"); R_AH = EMS_INVALID_SUB; break; } mp++; if (hpagenum == 0xffff) { /* Unmap only */ map_page(0, position, handle, 1); continue; } if (hpagenum >= ems_handle[handle]->npages) { R_AH = EMS_LOGPAGE_TOOBIG; break; } spagenum = ems_handle[handle]->pagenum[hpagenum]; map_page(spagenum, position, handle, 0); } break; } case REALLOC_PAGES: { short handle; u_long newpages; debug(D_EMS, "EMS: Realloc pages "); handle = R_DX; if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; debug(D_EMS, "invalid handle\n"); break; } newpages = R_BX; debug(D_EMS, "changed from %ld to %ld pages\n", ems_handle[handle]->npages, newpages); /* Case 1: Realloc to zero pages */ if (newpages == 0) { free_pages_of_handle(handle); R_AH = EMS_SUCCESS; break; } /* Case 2: New allocation is equal to allocated number */ if (newpages == ems_handle[handle]->npages) { R_AH = EMS_SUCCESS; break; } /* Case 3: Reallocate to bigger and smaller sizes */ if (newpages > ems_handle[handle]->npages) { if (newpages > ems_free_pages) { R_AH = EMS_OUT_OF_LOG; break; } if (newpages > ems_total_pages) { R_AH = EMS_OUT_OF_PHYS; break; } } reallocate_pages_to_handle(handle, newpages); R_AH = EMS_SUCCESS; break; } /* We do not support nonvolatile pages */ case HANDLE_ATTRIBUTES: debug(D_EMS, "Handle attributes called\n"); switch (R_AL) { case GET: case SET: R_AH = EMS_FEAT_NOSUP; break; case HANDLE_CAPABILITY: R_AL = 0; /* Volatile only */ R_AH = EMS_SUCCESS; break; default: R_AH = EMS_FUNC_NOSUP; break; } break; case HANDLE_NAME: { short handle; Hname *hp; handle = R_DX; if (handle > 255 || handle == 0 || ems_handle[handle] == NULL) { R_AH = EMS_INV_HANDLE; debug(D_EMS, "invalid handle\n"); break; } switch (R_AL) { case GET: if ((hp = (Hname *)get_valid_pointer(R_ES, R_DI, 8)) == NULL) { R_AH = EMS_SW_MALFUNC; break; } *hp = ems_handle[handle]->hname; R_AH = EMS_SUCCESS; break; case SET: if ((hp = (Hname *)get_valid_pointer(R_DS, R_SI, 8)) == NULL) { R_AH = EMS_SW_MALFUNC; break; } /* If the handle name is not 0, it may not exist */ if ((hp->ul_hn[0] | hp->ul_hn[1]) != 0) { if (lookup_handle(hp) == 0) { ems_handle[handle]->hname = *hp; R_AH = EMS_SUCCESS; } else { R_AH = EMS_NAME_EXISTS; break; } } else { /* Name is deleted (set to zeros) */ ems_handle[handle]->hname = *hp; R_AH = EMS_SUCCESS; } break; default: R_AH = EMS_FUNC_NOSUP; break; } break; } case HANDLE_DIRECTORY: { int i; EMShandledir *hdp; Hname *hp; short handle; switch(R_AL) { case GET: hdp = (EMShandledir *)get_valid_pointer(R_ES, R_DI, sizeof(EMShandledir) * ems_alloc_handles); if (hdp == NULL) { R_AH = EMS_SW_MALFUNC; break; } for (i = 0; i < EMS_NUM_HANDLES; i++) { if (ems_handle[i] != NULL) { hdp->log = i; hdp->name = ems_handle[i]->hname; } } R_AH = EMS_SUCCESS; break; case HANDLE_SEARCH: hp = (Hname *)get_valid_pointer(R_DS, R_SI, 8); if (hp == NULL) { R_AH = EMS_SW_MALFUNC; break; } /* Cannot search for NULL handle name */ if ((hp->ul_hn[0] | hp->ul_hn[1]) != 0) { R_AH = EMS_NAME_EXISTS; break; } if ((handle = lookup_handle(hp)) == 0) { R_AH = EMS_HNAME_NOT_FOUND; } else { R_DX = handle; R_AH = EMS_SUCCESS; } break; case GET_TOTAL_HANDLES: R_AH = EMS_SUCCESS; R_BX = EMS_NUM_HANDLES; /* Includes OS handle */ break; default: R_AH = EMS_FUNC_NOSUP; break; } break; } /* I do not know if we need this. LINUX emulation leaves it out * so I leave it out too for now. */ case ALTER_PAGEMAP_JUMP: debug(D_ALWAYS, "Alter pagemap and jump used!\n"); R_AH = EMS_FUNC_NOSUP; break; case ALTER_PAGEMAP_CALL: debug(D_ALWAYS, "Alter pagemap and call used!\n"); R_AH = EMS_FUNC_NOSUP; break; case MOVE_MEMORY_REGION: { EMSmovemem *emvp; u_long src_addr, dst_addr; u_short src_handle, dst_handle; if (R_AL == EXCHANGE) debug(D_EMS, "EMS: Exchange memory region "); else debug(D_EMS, "EMS: Move memory region "); emvp = (EMSmovemem *)get_valid_pointer(R_DS, R_SI, sizeof(EMSmovemem)); if (emvp == NULL) { debug(D_EMS, "Invalid structure pointer\n"); R_AH = EMS_SW_MALFUNC; break; } /* Zero length is not an error */ if (emvp->length == 0) { debug(D_EMS, "Zero length\n"); R_AH = EMS_SUCCESS; break; } /* Some checks */ if (emvp->src_type == EMS_MOVE_CONV) { /* Conventional memory source */ src_addr = MAKEPTR(emvp->src_seg, emvp->src_offset); /* May not exceed conventional memory */ if ((src_addr + emvp->length) > 640 * 1024) { R_AH = EMS_SW_MALFUNC; break; } } else { /* Check the handle */ src_handle = emvp->src_handle; if (src_handle > 255 || src_handle == 0 || ems_handle[src_handle] == NULL) { R_AH = EMS_INV_HANDLE; debug(D_EMS, "invalid source handle\n"); break; } /* Offset may not exceed page size */ if (emvp->src_offset >= (16 * 1024)) { R_AH = EMS_PAGEOFFSET; debug(D_EMS, "source page offset too big\n"); break; } } if (emvp->dst_type == EMS_MOVE_CONV) { /* Conventional memory source */ dst_addr = MAKEPTR(emvp->dst_seg, emvp->dst_offset); /* May not exceed conventional memory */ if ((dst_addr + emvp->length) > 640 * 1024) { R_AH = EMS_SW_MALFUNC; break; } } else { /* Check the handle */ dst_handle = emvp->dst_handle; if (dst_handle > 255 || dst_handle == 0 || ems_handle[dst_handle] == NULL) { R_AH = EMS_INV_HANDLE; debug(D_EMS, "invalid destination handle\n"); break; } /* Offset may not exceed page size */ if (emvp->dst_offset >= (16 * 1024)) { R_AH = EMS_PAGEOFFSET; debug(D_EMS, "destination page offset too big\n"); break; } } if (R_AL == MOVE) { /* If it is conventional memory only, do it */ if (emvp->src_type == EMS_MOVE_CONV && emvp->dst_type == EMS_MOVE_CONV) { memmove((void *)dst_addr, (void *)src_addr, (size_t) emvp->length); debug(D_EMS, "conventional to conventional memory done\n"); R_AH = EMS_SUCCESS; break; } if (emvp->src_type == EMS_MOVE_EMS && emvp->dst_type == EMS_MOVE_CONV) R_AH = move_ems_to_conv(src_handle, emvp->src_seg, emvp->src_offset, dst_addr, emvp->length); else if (emvp->src_type == EMS_MOVE_CONV && emvp->dst_type == EMS_MOVE_EMS) R_AH = move_conv_to_ems(src_addr, dst_handle, emvp->dst_seg, emvp->dst_offset, emvp->length); else R_AH = move_ems_to_ems(src_handle, emvp->src_seg, emvp->src_offset, dst_handle, emvp->dst_seg, emvp->dst_offset, emvp->length); debug(D_EMS, " done\n"); break; } else { /* exchange memory region */ /* We need a scratch area for the exchange */ void *buffer; if ((buffer = malloc(emvp->length)) == NULL) fatal("EMS: Could not malloc scratch area for exchange"); /* If it is conventional memory only, do it */ if (emvp->src_type == EMS_MOVE_CONV && emvp->dst_type == EMS_MOVE_CONV) { /* destination -> buffer */ memmove(buffer, (void *)dst_addr, (size_t) emvp->length); /* Source -> destination */ memmove((void *)dst_addr, (void *)src_addr, (size_t) emvp->length); /* Buffer -> source */ memmove((void *)src_addr, buffer, (size_t) emvp->length); free(buffer); debug(D_EMS, "conventional to conventional memory done\n"); R_AH = EMS_SUCCESS; break; } /* Exchange EMS with conventional */ if (emvp->src_type == EMS_MOVE_EMS && emvp->dst_type == EMS_MOVE_CONV) { /* Destination -> buffer */ memmove(buffer, (void *)dst_addr, (size_t) emvp->length); /* Source -> destination */ R_AH = move_ems_to_conv(src_handle, emvp->src_seg, emvp->src_offset, dst_addr, emvp->length); if (R_AH != EMS_SUCCESS) { free(buffer); break; } /* Buffer -> source */ R_AH = move_conv_to_ems((u_long)buffer, src_handle, emvp->src_seg, emvp->src_offset, emvp->length); /* Exchange conventional with EMS */ } else if (emvp->src_type == EMS_MOVE_CONV && emvp->dst_type == EMS_MOVE_EMS) { /* Destination -> buffer */ R_AH = move_ems_to_conv(dst_handle, emvp->dst_seg, emvp->dst_offset, (u_long)buffer, emvp->length); if (R_AH != EMS_SUCCESS) { free(buffer); break; } /* Source -> destination */ R_AH = move_conv_to_ems((u_long)buffer, dst_handle, emvp->dst_seg, emvp->dst_offset, emvp->length); /* Buffer -> source */ memmove(buffer, (void *)src_addr, (size_t) emvp->length); /* Exchange EMS with EMS */ } else { /* Destination -> buffer */ R_AH = move_ems_to_conv(dst_handle, emvp->dst_seg, emvp->dst_offset, (u_long)buffer, emvp->length); if (R_AH != EMS_SUCCESS) { free(buffer); break; } /* Source -> destination */ R_AH = move_ems_to_ems(src_handle, emvp->src_seg, emvp->src_offset, dst_handle, emvp->dst_seg, emvp->dst_offset, emvp->length); if (R_AH != EMS_SUCCESS) { free(buffer); break; } /* Buffer -> source */ R_AH = move_conv_to_ems((u_long)buffer, src_handle, emvp->src_seg, emvp->src_offset, emvp->length); } free(buffer); } debug(D_EMS, " done\n"); break; } case GET_MAPPABLE_PHYS_ADDR: { switch (R_AL) { case GET_ARRAY: { EMSaddrarray *eadp; int i; u_short seg; eadp = (EMSaddrarray *)get_valid_pointer(R_ES, R_DI, sizeof(EMSaddrarray) * 4); if (eadp == NULL) { R_AH = EMS_SW_MALFUNC; break; } for (i = 0, seg = (ems_frame_addr >> 4); i < 4; i++) { eadp->segm = seg; eadp->phys = i; eadp++; seg += 1024; } R_AH = EMS_SUCCESS; break; } case GET_ARRAY_ENTRIES: /* There are always 4 positions, 4*16kB = 64kB */ R_CX = 4; R_AH = EMS_SUCCESS; break; default: R_AH = EMS_FUNC_NOSUP; break; } break; } /* This is an OS function in the LIM EMS 4.0 standard: It is * usable only by an OS and its use can be disabled for all other * programs. I think we do not need to support it. It is not * implemented and it reports "disabled" to any caller. */ case GET_HW_CONFIGURATION: R_AH = EMS_FUNCTION_DISABLED; break; /* This function is a little different, it was defined with * LIM EMS 4.0: It is allowed to allocate zero pages and raw * page size (i.e. page size != 16kB) is supported. We have * only 16kB pages, so the second difference does not matter. */ case ALLOCATE_PAGES: { u_short npages; short handle; npages = R_BX; debug(D_EMS, "EMS: Get handle and allocate %d pages: ", npages); /* Enough handles? */ if ((handle = find_next_free_handle()) < 0) { debug(D_EMS,"Return error:No handles\n"); R_AH = EMS_OUT_OF_HANDLES; break; } /* Enough memory for this request ? */ if (npages > ems_free_pages) { debug(D_EMS,"Return error:Request too big\n"); R_AH = EMS_OUT_OF_LOG; break; } if (npages > ems_total_pages) { debug(D_EMS,"Return error:Request too big\n"); R_AH = EMS_OUT_OF_PHYS; break; } /* Allocate the handle */ allocate_handle(handle, npages); /* Allocate the pages */ allocate_pages_to_handle(handle, npages); R_DX = handle; R_AH = EMS_SUCCESS; debug(D_EMS,"Return success:Handle = %d\n", handle); break; } /* This is an OS function in the LIM EMS 4.0 standard: It is * usable only by an OS and its use can be disabled for all other * programs. I think we do not need to support it. It is not * implemented and it reports "disabled" to any caller. */ case ALTERNATE_MAP_REGISTER: R_AH = EMS_FUNCTION_DISABLED; break; /* We cannot support that ! */ case PREPARE_WARMBOOT: R_AH = EMS_FUNC_NOSUP; break; case OS_FUNCTION_SET: R_AH = EMS_FUNCTION_DISABLED; break; default: debug(D_ALWAYS, "EMS: Unknown function called: %02x\n", R_AH); R_AH = EMS_FUNC_NOSUP; break; } } /* Initialize the EMS memory: Return 1 on success, 0 on failure */ static int init_mapfile() { char path[256]; int mfd; /* Sanity */ if (ems_max_size == 0) return 0; strcpy(path, EMS_MAP_PATH); strcat(path, EMS_MAP_FILE); mfd = mkstemp(path); if (mfd < 0) { debug(D_ALWAYS, "Could not create EMS mapfile, "); goto fail; } unlink(path); mapfile_fd = squirrel_fd(mfd); if (lseek(mapfile_fd, (off_t)(ems_max_size - 1), 0) < 0) { debug(D_ALWAYS, "Could not seek into EMS mapfile, "); goto fail; } if (write(mapfile_fd, "", 1) < 0) { debug(D_ALWAYS, "Could not write to EMS mapfile, "); goto fail; } /* Unmap the entire page frame */ if (munmap((caddr_t)ems_frame_addr, 64 * 1024) < 0) { debug(D_ALWAYS, "Could not unmap EMS page frame, "); goto fail; } /* DOS programs will access the page frame without allocating * pages first. Microsoft diagnose MSD.EXE does this, for example * We need to have memory here to avoid segmentation violation */ if (mmap((caddr_t)ems_frame_addr, 64 * 1024, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_ANON | MAP_FIXED | MAP_SHARED, -1, 0) == MAP_FAILED) { debug(D_ALWAYS, "Could not map EMS page frame, "); goto fail; } bzero((void *)&ems_mapping_context, sizeof(EMS_mapping_context)); return (1); fail: debug(D_ALWAYS, "EMS disabled\n"); ems_max_size = 0; ems_frame_addr = 0; return (0); } /* Map/Unmap pages into one of four positions in the frame segment */ static void map_page(u_long pagenum, u_char position, short handle, int unmaponly) { caddr_t map_addr; size_t len; off_t file_offs; if (position > 3) fatal("EMS: Internal error: Mapping position\n"); map_addr = (caddr_t)(ems_frame_addr + (1024 * 16 * (u_long)position)); len = 1024 * 16; file_offs = (off_t)(pagenum * 16 * 1024); if (ems_mapping_context.pos_mapped[position]) { if (munmap(map_addr, len) < 0) { fatal("EMS unmapping error: %s\nCannot recover\n", strerror(errno)); } ems_page[ems_mapping_context.pos_pagenum[position]].status &= ~EMS_MAPPED; ems_mapping_context.pos_mapped[position] = 0; ems_mapping_context.handle[position] = 0; } if (unmaponly) { /* DOS programs will access the page frame without allocating * pages first. Microsoft diagnose MSD.EXE does this, for example * We need to have memory here to avoid segmentation violation */ if (mmap((caddr_t)ems_frame_addr, 64 * 1024, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_ANON | MAP_FIXED | MAP_SHARED, -1, 0) == MAP_FAILED) fatal("Could not map EMS page frame during unmap only\n"); return; } if (mmap(map_addr, len, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_FILE | MAP_FIXED | MAP_SHARED, mapfile_fd, file_offs) == MAP_FAILED) { fatal("EMS mapping error: %s\nCannot recover\n", strerror(errno)); } ems_mapping_context.pos_mapped[position] = 1; ems_mapping_context.pos_pagenum[position] = pagenum; ems_mapping_context.handle[position] = handle; ems_page[pagenum].status |= EMS_MAPPED; } /* Get a pointer from VM86 app, check it and return it. This returns NULL * if the pointer is not valid. We can check only for very limited * criteria: The pointer and the area defined by size may not point to * memory over 1MB and it may not may to addresses under 1kB, because there * is the VM86 interrupt table. */ static void *get_valid_pointer(u_short seg, u_short offs, u_long size) { u_long addr; addr = MAKEPTR(seg, offs); /* Check bounds */ if ((addr + size) >= (1024 * 1024) || addr < 1024) return NULL; else return (void *)addr; } /* Malloc a new handle */ static EMS_handle *get_new_handle(long npages) { EMS_handle *ehp; size_t dynsize = sizeof(EMS_handle) + sizeof(short) * npages; if ((ehp = calloc(1, dynsize)) == NULL) fatal("Cannot malloc EMS handle, cannot continue\n"); return ehp; } /* Allocate a mapping context to a handle */ static void context_to_handle(short handle) { EMS_mapping_context *emc; if (ems_handle[handle] == NULL) fatal("EMS context_to_handle called with invalid handle\n"); if ((emc = calloc(1, sizeof(EMS_mapping_context))) == NULL) fatal("EMS Cannot malloc mapping context, cannot continue\n"); ems_handle[handle]->mcontext = emc; memmove((void *)emc, (void *)&ems_mapping_context, sizeof(EMS_mapping_context)); } /* Find the next free handle, returns -1 if there are no more handles */ static long find_next_free_handle() { int i; if (ems_alloc_handles >= 255) return (-1); /* handle 0 is OS handle */ for (i = 1; i < EMS_NUM_HANDLES; i++) { if (ems_handle[i] == NULL) return (i); } fatal("EMS handle count garbled, should not happen\n"); /* quiet 'gcc -Wall' */ return (-1); } /* Look for a named handle, returns 0 if not found, else handle */ static short lookup_handle(Hname *hp) { int i; for (i = 1; i < EMS_NUM_HANDLES; i++) { if (ems_handle[i] != NULL) { if (hp->ul_hn[0] == ems_handle[i]->hname.ul_hn[0] && hp->ul_hn[1] == ems_handle[i]->hname.ul_hn[1]) return (i); } } return (0); } /* Malloc a new handle struct and put into array at index handle */ static void allocate_handle(short handle, long npages) { if (ems_handle[handle] != NULL) fatal("EMS allocate_handle, handle was not free\n"); ems_handle[handle] = get_new_handle(npages); ems_alloc_handles++; } /* Free a handle, return its memory. Call this *after* freeing the * allocated pages ! */ static void free_handle(short handle) { if (ems_handle[handle] == NULL) fatal("EMS free_handle, handle was free\n"); if (ems_handle[handle]->mcontext != NULL) free((void *)ems_handle[handle]->mcontext); free((void *)ems_handle[handle]); ems_handle[handle] = NULL; ems_alloc_handles--; } /* Allocates npages to handle. Call this routine only after you have * ensured there are enough free pages *and* the new handle is in place * in the handle array ! */ static void allocate_pages_to_handle(u_short handle, long npages) { unsigned syspagenum; int pages_to_alloc = npages; int allocpagenum = 0; /* sanity */ if (handle > 255 || ems_handle[handle] == NULL) fatal("EMS allocate_pages_to_handle called with invalid handle\n"); ems_handle[handle]->npages = npages; for (syspagenum = 0; syspagenum < ems_total_pages; syspagenum++) { if (ems_page[syspagenum].status == EMS_FREE) { ems_page[syspagenum].handle = handle; ems_page[syspagenum].status = EMS_ALLOCED; ems_handle[handle]->pagenum[allocpagenum] = syspagenum; allocpagenum++; pages_to_alloc--; if (pages_to_alloc == 0) break; } } if (pages_to_alloc > 0) fatal("EMS allocate_pages_to_handle found not enough free pages\n"); ems_alloc_pages += npages; ems_free_pages -= npages; } /* Reallocates npages to handle. Call this routine only after you have * ensured there are enough free pages *and* the new handle is in place * in the handle array ! */ static void reallocate_pages_to_handle(u_short handle, long npages) { unsigned allocpagenum; unsigned syspagenum; int pages_to_alloc; long delta; size_t dynsize; EMS_handle *emp; /* sanity */ if (handle > 255 || ems_handle[handle] == NULL) fatal("EMS allocate_pages_to_handle called with invalid handle\n"); delta = npages - ems_handle[handle]->npages; if (delta > 0) { /* Grow array size and allocation */ emp = ems_handle[handle]; dynsize = sizeof(EMS_handle) + sizeof(short) * npages; /* First step: Make room in the handle pagenum array */ if ((emp = (EMS_handle *)realloc((void *)emp, dynsize)) == NULL) fatal("Cannot malloc EMS handle, cannot continue\n"); ems_handle[handle] = emp; /* Second step: Add pages to the handle */ pages_to_alloc = delta; allocpagenum = ems_handle[handle]->npages; ems_handle[handle]->npages = npages; for (syspagenum = 0; syspagenum < ems_total_pages; syspagenum++) { if (ems_page[syspagenum].status == EMS_FREE) { ems_page[syspagenum].handle = handle; ems_page[syspagenum].status = EMS_ALLOCED; ems_handle[handle]->pagenum[allocpagenum] = syspagenum; allocpagenum++; pages_to_alloc--; if (pages_to_alloc == 0) break; } } if (pages_to_alloc > 0) fatal("EMS allocate_pages_to_handle found not enough free pages\n"); } else { /* Shrink array size and allocation */ /* First step: Deallocate all pages from new size to old size */ for (allocpagenum = npages; allocpagenum < ems_handle[handle]->npages; allocpagenum++) { syspagenum = ems_handle[handle]->pagenum[allocpagenum]; /* sanity */ if (syspagenum > ems_total_pages) fatal("EMS free_pages_of_handle found invalid page number\n"); if (!(ems_page[syspagenum].status & EMS_ALLOCED)) fatal("EMS free_pages_of_handle tried to free page already free\n"); ems_page[syspagenum].handle = 0; ems_page[syspagenum].status = EMS_FREE; } /* Second step: Shrink the dynamic array of the handle */ dynsize = sizeof(EMS_handle) + sizeof(short) * npages; emp = ems_handle[handle]; if ((emp = (EMS_handle *)realloc((void *)emp, dynsize)) == NULL) fatal("Cannot realloc EMS handle, cannot continue\n"); ems_handle[handle] = emp; ems_handle[handle]->npages = npages; } ems_alloc_pages += delta; ems_free_pages -= delta; } /* Free all pages belonging to a handle, handle must be valid */ static void free_pages_of_handle(short handle) { int allocpagenum; unsigned syspagenum; int npages; /* sanity */ if (handle > 255 || ems_handle[handle] == NULL) fatal("EMS free_pages_of_handle called with invalid handle\n"); if ((npages = ems_handle[handle]->npages) == 0) return; for (allocpagenum = 0; allocpagenum < npages; allocpagenum++) { syspagenum = ems_handle[handle]->pagenum[allocpagenum]; /* sanity */ if (syspagenum > ems_total_pages) fatal("EMS free_pages_of_handle found invalid page number\n"); if (!(ems_page[syspagenum].status & EMS_ALLOCED)) fatal("EMS free_pages_of_handle tried to free page already free\n"); ems_page[syspagenum].handle = 0; ems_page[syspagenum].status = EMS_FREE; } ems_alloc_pages -= npages; ems_free_pages += npages; } /* Restore a saved mapping context, overwrites current mapping context */ static void restore_context(EMS_mapping_context *emc) { int i; for (i = 0; i < 4; i++) { ems_mapping_context.handle[i] = emc->handle[i]; if (emc->pos_mapped[i] != 0 && ems_mapping_context.pos_pagenum[i] != emc->pos_pagenum[i]) { map_page(emc->pos_pagenum[i], (u_char) i, emc->handle[i], 0); } else { ems_mapping_context.pos_mapped[i] = 0; } } } /* Prepare a special context save block for DOS and save it to * VM86 memory */ static void save_context_to_dos(EMScontext *emp) { int i, end; EMScontext context; u_short *sp; u_short sum; context.ems_saved_context = ems_mapping_context; context.magic = EMS_SAVEMAGIC; context.checksum = 0; sp = (u_short *)&context; end = sizeof(EMScontext) / sizeof(short); /* Generate checksum */ for (i = 0, sum = 0; i < end; i++) { sum += *sp++; sum &= 0xffff; } context.checksum = 0x10000L - sum; /* Save it to VM86 memory */ *emp = context; } /* Check a context returned from VM86 app for validity, return 0, if * not valid, else return 1 */ static int check_saved_context(EMScontext *emp) { int i, end; u_short *sp; u_short sum; if (emp->magic != EMS_SAVEMAGIC) return 0; sp = (u_short *)emp; end = sizeof(EMScontext) / sizeof(short); /* Generate checksum */ for (i = 0, sum = 0; i < end; i++) { sum += *sp++; sum &= 0xffff; } if (sum != 0) return 0; else return 1; } /* Helper routine for the move routines below: Check if length bytes * can be moved from/to handle pages (i.e are there enough pages) */ static int check_alloc_pages(u_short handle, u_short firstpage, u_short offset, u_long length __unused) { u_long nbytes; if (firstpage > ems_handle[handle]->npages) return (0); nbytes = (ems_handle[handle]->npages - firstpage) * EMS_PAGESIZE - offset; return (ems_handle[handle]->npages >= nbytes); } /* Copy a block of memory up to the next 16kB boundary in the source * to the destination in upward direction (i.e. with ascending addresses) * XXX Could be an inline function. */ static void copy_block_up(struct copydesc *cdp) { size_t size; void *srcp; void *dstp; /* If source or both memory types are EMS, source determines the * block lenght, else destination determines the block lenght */ if (cdp->copytype & SRC_EMS) size = EMS_PAGESIZE - cdp->EMS_OFFS(src_addr); else size = EMS_PAGESIZE - cdp->EMS_OFFS(dst_addr); if (size > cdp->rest_len) size = cdp->rest_len; /* If src is EMS memory, it is mapped into position 0 */ if (cdp->copytype & SRC_EMS) srcp = (void *)(ems_frame_addr + cdp->EMS_OFFS(src_addr)); else srcp = (void *)(cdp->EMS_PTR(src_addr)); /* If dest is EMS memory, it is mapped into position 1,2 */ if (cdp->copytype & DST_EMS) dstp = (void *)(ems_frame_addr + EMS_PAGESIZE + cdp->EMS_OFFS(dst_addr)); else dstp = (void *)(cdp->EMS_PTR(dst_addr)); /* Move this block */ memmove(dstp, srcp, size); /* Update the copy descriptor: This updates the address of both * conventional and EMS memory */ cdp->EMS_PTR(src_addr) += size; cdp->EMS_PTR(dst_addr) += size; cdp->rest_len -= size; } /* Move EMS memory starting with handle page src_seg and offset src_offset * to conventional memory dst_addr for length bytes * dst_addr is checked, handle is valid */ static u_long move_ems_to_conv(short src_handle, u_short src_seg, u_short src_offset, u_long dst_addr, u_long length) { EMS_mapping_context ems_saved_context; EMS_handle *ehp; int pageindx = src_seg; struct copydesc cd; if (check_alloc_pages(src_handle, src_seg, src_offset, length) == 0) return EMS_MOVE_OVERFLOW; ehp = ems_handle[src_handle]; /* Prepare the move: Save the mapping context */ ems_saved_context = ems_mapping_context; /* Setup the copy descriptor struct */ cd.copytype = SRC_EMS; cd.EMS_PAGE(src_addr) = ehp->pagenum[pageindx]; cd.EMS_OFFS(src_addr) = src_offset; cd.EMS_PTR(dst_addr) = dst_addr; cd.rest_len = length; do { /* Map for the first block copy, source is mapped to position zero */ map_page(cd.EMS_PAGE(src_addr), 0, src_handle, 0); copy_block_up(&cd); } while(cd.rest_len > 0); /* Restore the original mapping */ restore_context(&ems_saved_context); return EMS_SUCCESS; } /* Move conventional memory starting with src_addr * to EMS memory starting with handle page src_seg and offset src_offset * for length bytes * dst_addr is checked, handle is valid */ static u_long move_conv_to_ems(u_long src_addr, u_short dst_handle, u_short dst_seg, u_short dst_offset, u_long length) { EMS_mapping_context ems_saved_context; EMS_handle *ehp; int pageindx = dst_seg; struct copydesc cd; if (check_alloc_pages(dst_handle, dst_seg, dst_offset, length) == 0) return EMS_MOVE_OVERFLOW; ehp = ems_handle[dst_handle]; /* Prepare the move: Save the mapping context */ ems_saved_context = ems_mapping_context; /* Setup the copy descriptor struct */ cd.copytype = DST_EMS; cd.EMS_PAGE(dst_addr) = ehp->pagenum[pageindx]; cd.EMS_OFFS(dst_addr) = dst_offset; cd.EMS_PTR(src_addr) = src_addr; cd.rest_len = length; do { map_page(cd.EMS_PAGE(dst_addr), 1, dst_handle, 0); copy_block_up(&cd); } while(cd.rest_len > 0); /* Restore the original mapping */ restore_context(&ems_saved_context); return EMS_SUCCESS; } static u_long move_ems_to_ems(u_short src_handle, u_short src_seg, u_short src_offset, u_short dst_handle, u_short dst_seg, u_short dst_offset, u_long length) { EMS_mapping_context ems_saved_context; EMS_handle *src_hp, *dst_hp; struct copydesc cd; if (check_alloc_pages(src_handle, src_seg, src_offset, length) == 0) return EMS_MOVE_OVERFLOW; if (check_alloc_pages(dst_handle, dst_seg, dst_offset, length) == 0) return EMS_MOVE_OVERFLOW; src_hp = ems_handle[src_handle]; dst_hp = ems_handle[dst_handle]; /* Prepare the move: Save the mapping context */ ems_saved_context = ems_mapping_context; /* Setup the copy descriptor struct */ cd.copytype = SRC_EMS | DST_EMS; cd.EMS_PAGE(src_addr) = src_hp->pagenum[src_seg]; cd.EMS_OFFS(src_addr) = src_offset; cd.EMS_PAGE(dst_addr) = dst_hp->pagenum[dst_seg]; cd.EMS_OFFS(dst_addr) = dst_offset; cd.rest_len = length; /* Copy */ do { map_page(cd.EMS_PAGE(src_addr), 0, src_handle, 0); map_page(cd.EMS_PAGE(dst_addr), 1, dst_handle, 0); /* If there are more pages, map the next destination page to * position 2. This removes a compare between source and dest * offsets. */ if (cd.EMS_PAGE(dst_addr) < dst_hp->npages) map_page((cd.EMS_PAGE(dst_addr) + 1), 2, dst_handle, 0); copy_block_up(&cd); } while(cd.rest_len > 0); /* Restore the original mapping */ restore_context(&ems_saved_context); return EMS_SUCCESS; }