static int execSyscall(int* args) {
return sysexecv((const char*)args[0], (char * const *)args[1]);
}
void
mips_syscall(struct trapframe *tf)
{
int callno;
int32_t retval;
int err;
int s,act;
char *d;
//convert user level pointers to user level pointers
assert(curspl==0);
callno = tf->tf_v0;
/*
* Initialize retval to 0. Many of the system calls don't
* really return a value, just 0 for success and -1 on
* error. Since retval is the value returned on success,
* initialize it to 0 by default; thus it's not necessary to
* deal with it except for calls that return other values,
* like write.
*/
retval = 0;
switch (callno) {
case SYS_reboot:
err = sys_reboot(tf->tf_a0);
break;
// syscall.h has all the callno numbers for differnt syscalls
case SYS_fork:
err = sysfork(&retval,tf);
break;
case SYS_getpid :
err = sysgetpid(&retval);
break;
case SYS_write :
s=splhigh();
char *c = (char *)tf->tf_a1;
kprintf("%c",*c);
retval = 1;
splx(s);
err=0;
break;
case SYS_read :
d = (char *)kmalloc(sizeof(char)*((tf->tf_a2)+1));
//char *b;
//b = (char *)kmalloc(sizeof(char)*((tf->tf_a2)+1));
d[0] = getch();
d[1] ='\0';
putch(d[0]);
putch('\n');
s=splhigh();
copyoutstr(d,(userptr_t)(tf->tf_a1),(tf->tf_a2)+1,&act);
//DEBUG(1,"actual: %d tf size: %d\n",act,(tf->tf_a2)+1);
//copyinstr((tf->tf_a1),b,(tf->tf_a2)+1,&act);
//DEBUG(1,"copied bacl:%s\n",b);
err=0;
kfree(d);
retval = strlen(d)+1;
splx(s);
break;
case SYS_waitpid :
err = syswaitpid(tf->tf_a0,(int *)tf->tf_a1,tf->tf_a2,&retval);
//syswaitpid(&retval);
break;
case SYS__exit :
err = sysexit(&retval,tf);
break;
case SYS_execv:
err=sysexecv((char*)tf->tf_a0, (char**)tf->tf_a1);
break;
case SYS_sbrk:
err = sys_sbrk((int)tf->tf_a0, &retval);
break;
default:
kprintf("Unknown syscall %d\n", callno);
err = ENOSYS;
break;
}
if (err) {
/*
* Return the error code. This gets converted at
* userlevel to a return value of -1 and the error
* code in errno.
*/
tf->tf_v0 = err;
tf->tf_a3 = 1; /* signal an error */
}
else {
/* Success. */
tf->tf_v0 = retval;
tf->tf_a3 = 0; /* signal no error */
}
/*
* Now, advance the program counter, to avoid restarting
* the syscall over and over again.
*/
tf->tf_epc += 4;
/* Make sure the syscall code didn't forget to lower spl */
assert(curspl==0);
}
