kernel2/syscall.c

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <sys/types.h>
  20 #include <stdint.h>
  21 #include <string.h>
  22 #include <syscall.h>
  23 #include <procm.h>
  24 #include <signal.h>
  25 #include <debug.h>
  26 #include <interrupt.h>
  27 #include <dyncall.h>
  28
  29 /**
  30  * Initializes Syscall Management
  31  *  @return 0=Success; -1=Failure
  32  */
  33 int syscall_init() {
  34   memset(&syscalls,0,SYSCALL_MAXNUM*sizeof(struct syscall));
  35   return 0;
  36 }
  37
  38 /**
  39  * Syscall handler
  40  *  @param params Pointer to parameter list
  41  */
  42 void syscall_handler(uint32_t *stack) {
  43   proc_t *proc_call = proc_current;
  44   int res = -1;
  45   interrupt_save_stack(stack,NULL);
  46   int cmd = ((int*)*interrupt_curregs.esp)[0];
  47   int *params = ((void**)*interrupt_curregs.esp)[1];
  48
  49   if (cmd<=SYSCALL_MAXNUM) {
  50     if (syscalls[cmd].func!=NULL) res = dyn_call(syscalls[cmd].func,params,syscalls[cmd].numparams);
  51     else kill(proc_current,SIGSYS);
  52   }
  53
  54   if (proc_current==proc_call) *interrupt_curregs.eax = res;
  55 }
  56
  57 /**
  58  * Registers a syscall
  59  *  @param cmd Syscall number
  60  *  @param func Pointer to function
  61  *  @param numparams Number of parameters
  62  *  @return 0=Success; -1=Failure
  63  */
  64 int syscall_create(int cmd,void *func,int numparams) {
  65   if (cmd>SYSCALL_MAXNUM || syscalls[cmd].func!=NULL) return -1;
  66   syscalls[cmd].func = func;
  67   syscalls[cmd].numparams = numparams;
  68   return 0;
  69 }
  70
  71 /**
  72  * Unregisters a syscall
  73  *  @param cmd Syscall number
  74  */
  75 void syscall_destroy(int cmd) {
  76   if (cmd<SYSCALL_MAXNUM) syscalls[cmd].func = NULL;
  77 }