AcessNative/acesskernel_src/syscalls.c

   1 /*
   2  * Acess2 Native Kernel
   3  * - Acess kernel emulation on another OS using SDL and UDP
   4  *
   5  * Syscall Server
   6  */
   7 #include <acess.h>
   8 #include "../syscalls.h"
   9
  10 // === TYPES ===
  11 typedef int     (*tSyscallHandler)(const char *Format, void *Args);
  12
  13 // === MACROS ===
  14 #define SYSCALL3(_name, _call, _fmtstr, _t1, _t2, _t3) int _name(const char *fmt,void*args){\
  15         _t1 a1;_t2 a2;_t3 a3;\
  16         if(strcmp(fmt,_fmtstr)!=0)return 0;\
  17         a1 = *(_t1*)args;args+=sizeof(_t1);\
  18         a2 = *(_t2*)args;args+=sizeof(_t2);\
  19         a3 = *(_t3*)args;args+=sizeof(_t3);\
  20         return _call(a1,a2,a3);\
  21 }
  22
  23 #define SYSCALL2(_name, _call, _fmtstr, _t1, _t2) int _name(const char *fmt,void*args){\
  24         _t1 a1;_t2 a2;\
  25         if(strcmp(fmt,_fmtstr)!=0)return 0;\
  26         a1 = *(_t1*)args;args+=sizeof(_t1);\
  27         a2 = *(_t2*)args;args+=sizeof(_t2);\
  28         return _call(a1,a2);\
  29 }
  30
  31 #define SYSCALL1V(_name, _call, _fmtstr, _t1) int _name(const char *fmt, void*args){\
  32         _t1 a1;\
  33         if(strcmp(fmt,_fmtstr)!=0)return 0;\
  34         a1 = *(_t1*)args;args+=sizeof(_t1);\
  35         _call(a1);\
  36         return 0;\
  37 }
  38
  39 // === CODE ===
  40 int Syscall_Null(const char *Format, void *Args)
  41 {
  42         return 0;
  43 }
  44
  45 SYSCALL2(Syscall_Open, VFS_Open, "di", const char *, int);
  46 SYSCALL1V(Syscall_Close, VFS_Close, "i", int);
  47 SYSCALL3(Syscall_Read, VFS_Read, "iid", int, int, void *);
  48 SYSCALL3(Syscall_Write, VFS_Write, "iid", int, int, const void *);
  49
  50
  51 const tSyscallHandler   caSyscalls[] = {
  52         Syscall_Null,
  53         Syscall_Open,
  54         Syscall_Close,
  55         Syscall_Read,
  56         Syscall_Write
  57 };
  58 const int       ciNumSyscalls = sizeof(caSyscalls)/sizeof(caSyscalls[0]);
  59 /**
  60  * \brief Recieve a syscall structure from the server code
  61  */
  62 tRequestHeader *SyscallRecieve(tRequestHeader *Request)
  63 {
  64         char    formatString[Request->NParams+1];
  65         char    *inData = (char*)&Request->Params[Request->NParams+Request->NReturn];
  66          int    argListLen = 0;
  67          int    i, retVal;
  68
  69         if( Request->CallID > ciNumSyscalls ) {
  70                 return NULL;
  71         }
  72
  73         // Get size of argument list
  74         for( i = 0; i < Request->NParams; i ++ )
  75         {
  76                 switch(Request->Params[i].Type)
  77                 {
  78                 case ARG_TYPE_VOID:
  79                         formatString[i] = '-';
  80                         break;
  81                 case ARG_TYPE_INT32:
  82                         formatString[i] = 'i';
  83                         argListLen += sizeof(Uint32);
  84                         break;
  85                 case ARG_TYPE_INT64:
  86                         formatString[i] = 'I';
  87                         argListLen += sizeof(Uint64);
  88                         break;
  89                 case ARG_TYPE_DATA:
  90                         formatString[i] = 'd';
  91                         argListLen += sizeof(void*);
  92                         break;
  93                 default:
  94                         return NULL;    // ERROR!
  95                 }
  96         }
  97
  98         {
  99                 char    argListData[argListLen];
 100                 argListLen = 0;
 101                 // Build argument list
 102                 for( i = 0; i < Request->NParams; i ++ )
 103                 {
 104                         switch(Request->Params[i].Type)
 105                         {
 106                         case ARG_TYPE_VOID:
 107                                 break;
 108                         case ARG_TYPE_INT32:
 109                                 *(Uint32*)&argListData[argListLen] = *(Uint32*)inData;
 110                                 argListLen += sizeof(Uint32);
 111                                 inData += sizeof(Uint32);
 112                                 break;
 113                         case ARG_TYPE_INT64:
 114                                 *(Uint64*)&argListData[argListLen] = *(Uint64*)inData;
 115                                 argListLen += sizeof(Uint64);
 116                                 inData += sizeof(Uint64);
 117                                 break;
 118                         case ARG_TYPE_DATA:
 119                         case ARG_TYPE_STRING:
 120                                 *(void**)&argListData[argListLen] = *(void**)inData;
 121                                 argListLen += sizeof(void*);
 122                                 inData += sizeof(void*);
 123                                 break;
 124                         }
 125                 }
 126
 127                 retVal = caSyscalls[Request->CallID](formatString, argListData);
 128         }
 129
 130         return NULL;
 131 }