Listing 3

/// VANYDEVDc.c

// --------------------------------------------// Dynamically loadable VxD for ANYDEV board// --------------------------------------------#define WIN32_LEAN_AND_MEAN // Excludes un-needed parts of windows.h#include "windows.h"#include <e:ddk95inc32vmm.h>#include <e:ddk95inc32vwin32.h>#include <e:ddk95inc32debug.h>#include "VANYDEVD.H"// -------------------------------------// Externs defined in assembly module // -------------------------------------// These defined in assembly for the VMM.INC or VPICD.INC file inclusionextern DWORD GET_BD_MEM(void);extern DWORD Virt_IRQ(void);extern DWORD Get_IRQ_Status(void);extern void UNVirt_IRQ(DWORD IRQhandle);extern void End_ISR(DWORD IRQhandle);extern void Physically_Mask_IRQ(DWORD IRQhandle);extern void Physically_UNMask_IRQ(DWORD IRQhandle);// ------------------------// PRAGMA for this DATA // ------------------------// Establish segment#pragma data_seg ( "_LDATA","_LCODE")// ------------------------------------// Data structures MUST be INITIALIZED// ------------------------------------ADEV ANYDEVX = {0}; // Main structure for ANYDEV -- shared by app // ------------------------// PRAGMAS for this CODE // ------------------------// Establish segment#pragma code_seg ( "_LTEXT", "_LCODE" )//No stack checking for routines in this module#pragma check_stack(off)// ----------------// Disable hardware// ----------------void Disable_AnyDev(void){//This would likely be a port WRITE to DISABLE the board's interrupt }// ----------------// Enable hardware// ----------------void Enable_AnyDev(void){//This would likely be a port WRITE to ENABLE the board's interrupt }// --------------------------// ISR Processing for ANYDEV// --------------------------void Process_ISR(void){//This is where the user might SET FLAGS and indicators in the ANYDEVX structure//in order to notify the application that data is available below 1MB }// -----------------// ISR for ANYDEV// -----------------void _declspec(naked)ISR_ANYDEV(void){// Save registers_asm sti_asm pushad_asm pushfd//Process the ISR Process_ISR();//End ISR_asm clcEnd_ISR(ANYDEVX.IRQhandle);//Set GOOD return code_asm clc//Restore saved registers_asm popfd_asm popad_asm ret;}// -------------------// Virtualize the IRQ// -------------------DWORD CVirt_IRQ(void){// If in use by an instance of this program, RETURN with BAD codeif (ANYDEVX.IRQcount)return (BOGUSADDRESS);// If in use by another program, RETURN with BAD codeANYDEVX.IRQstatus = Get_IRQ_Status();if (ANYDEVX.IRQstatus)return (BOGUSADDRESS);// If IRQ NOT in use this point is reached// Set BAD return codeANYDEVX.IRQhandle = BOGUSADDRESS;// Disable ANYDEV hardwareDisable_AnyDev();// Get global memory address below 1mbANYDEVX.Global_addr_1MB = GET_BD_MEM();if (ANYDEVX.Global_addr_1MB != BOGUSADDRESS){// Virtualize the IRQANYDEVX.IRQhandle = Virt_IRQ();if (ANYDEVX.IRQhandle != BOGUSADDRESS){// unmask the IRQ, set OK flag & increment IRQ count Physically_UNMask_IRQ(ANYDEVX.IRQhandle); ANYDEVX.IRQflags = IRQ_VIRT_OK;++(ANYDEVX.IRQcount);}}return(ANYDEVX.IRQhandle);}// ----------------------// UN Virtualize the IRQ// ----------------------void CUNVirt_IRQ(DWORD IRQhandle){ // if IRQ has been successfully virtualized if ((ANYDEVX.IRQhandle != 0) &&  (ANYDEVX.IRQhandle != BOGUSADDRESS)) {// Physically mask the IRQ and UN virtualized itPhysically_Mask_IRQ(ANYDEVX.IRQhandle);UNVirt_IRQ(ANYDEVX.IRQhandle);}// Set UNvirtualized flags and indicatorsANYDEVX.IRQhandle = BOGUSADDRESS;ANYDEVX.IRQflags &= ~IRQ_VIRT_OK;return;}// ---------------------------------------// Set Good Return code for DIOC requests// ---------------------------------------void _declspec(naked)GoodReturnDIOC(void){// Clear eax and carry flag for GOOD return_asm xor eax,eax_asm clc_asm ret;}// ---------------------------------------// Set Bad Return code for DIOC requests// ---------------------------------------void _declspec(naked) BadReturnDIOC(void){// NOTE: 50 is a FCN NOT SUPPORTED code -- ok to use// SET carry flag for BAD return_asm mov eax,50_asm stc_asm ret;}// ------------------------------// Routine for ANYDEV Device UNINIT  // ------------------------------void CVANYDEVD_Device_UNInit(){// Disable ANYDEV, Unvirtualize IRQ, set GOOD return codeDisable_AnyDev();CUNVirt_IRQ(ANYDEVX.IRQhandle);GoodReturnDIOC();return;}// ------------------------------// Routine for ANYDEV Device INIT  // ------------------------------void CVANYDEVD_Device_Init(){DWORD retcode;// Try to virtualize the IRQretcode = CVirt_IRQ();// Set GOOD or BAD return code based on successif (retcode == BOGUSADDRESS)BadReturnDIOC();else    GoodReturnDIOC();return;}// --------------------------------// Routine for ANYDEV Device IO ctrl  // --------------------------------void CVANYDEVD_Device_IOctrl(PDIOCPARAMETERS ptr){DWORD *obuf1;// Field the DEV IO requests from VMMswitch(ptr->dwIoControlCode){case(VANYDEVD_INIT_ADEV_HARDWARE):ANYDEVX.flags = 0;//User likely to require other initialization herebreak;case(VANYDEVD_GRAB_ADDRESSES):// Point to Output bufferobuf1 = (DWORD *) ptr->lpvOutBuffer;// Return GLOBAL 1MB addr, addr of data structure// and return indicators of IRQ virtuaization request*obuf1 = ANYDEVX.Global_addr_1MB;  *(obuf1+1) = (DWORD) &ANYDEVX;*(obuf1+2) = (DWORD) ANYDEVX.IRQhandle;*(obuf1+3) = (DWORD) ANYDEVX.IRQflags;//User might want to return other/different values herebreak;case(VANYDEVD_ENABLE_ANYDEV_HDWR)://Call routine to enable interruptEnable_AnyDev();break;case(VANYDEVD_DISABLE_ANYDEV_HWR)://Call routine to disable interruptDisable_AnyDev();break;//The below DIOC_GETVERSION is a part of the dynamic load protocol//It MUST return a GOOD code (all codes here use GoodReturnDIOC()case(DIOC_GETVERSION):case(DIOC_CLOSEHANDLE):default:break;} GoodReturnDIOC();return;}