diff options
Diffstat (limited to 'usr.bin/doscmd/emuint.c')
| -rw-r--r-- | usr.bin/doscmd/emuint.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/usr.bin/doscmd/emuint.c b/usr.bin/doscmd/emuint.c new file mode 100644 index 0000000..1b2bfdd7 --- /dev/null +++ b/usr.bin/doscmd/emuint.c @@ -0,0 +1,111 @@ +/*- + * Copyright (c) 1997 Helmut Wirth <hfwirth@ping.at> + * 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. + * + * $Id$ + */ + +#include <sys/param.h> +#include <ctype.h> +#include "doscmd.h" +#include "emuint.h" + +/* The central entry point for the emulator interrupt. This is used by + * different special programs to call the emulator from VM86 space. + * Look at emuint.h for definitions and a list of the currently defined + * subfunctions. + * To call emuint from VM86 space do: + * push ax Save original ax value (*must be done* !) + * mov ah, funcnum Emuint function number to ah + * mov al, subfunc Subfunction number, optional, depening on func + * int 0xff + * .. + * .. + * Emuint saves the function and subfunction numbers internally, then + * pops ax off the stack and calls the function handler with the original + * value in ax. + */ +void +emuint(regcontext_t *REGS) +{ + u_short func, subfunc; + + /* Remove function number from stack */ + func = R_AH; + subfunc = R_AL; + + R_AX = N_POP(REGS); + + /* Call the function handler, subfunction is ignored, if unused */ + switch (func) + { + /* The redirector call */ + case EMU_REDIR: + intff(REGS); + break; + + /* EMS call, used by emsdriv.sys */ + case EMU_EMS: + { + switch (subfunc) + { + case EMU_EMS_CTL: + R_AX = (u_short)ems_init(); + break; + + case EMU_EMS_CALL: + ems_entry(REGS); + break; + + default: + debug(D_ALWAYS, "Undefined subfunction for EMS call\n"); + break; + } + break; + } + + default: + debug(D_ALWAYS, "Emulator interrupt called with undefined function %02x\n", func); + + /* + * XXX + * temporary backwards compatability with instbsdi.exe + * remove after a while. + */ + fprintf(stderr, "***\n*** WARNING - unknown emuint function\n"); + fprintf(stderr, "*** Continuing; assuming instbsdi redirector.\n"); + fprintf(stderr, "*** Please install the new redirector"); + fprintf(stderr, " `redir.com' as soon as possible.\n"); + fprintf(stderr, "*** This compatability hack is not permanent.\n"); + fprintf(stderr, "***\n"); + N_PUSH(R_AX, REGS); + R_BX = R_ES; + R_DX = R_DI; + R_DI = R_DS; + intff(REGS); + break; + } +} |
