Exemple #1
0
// Dispatches to the correct kernel function, passing the arguments.
int32_t
syscall(uint32_t syscallno, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
{
	// Call the function corresponding to the 'syscallno' parameter.
	// Return any appropriate return value.
	// LAB 3: Your code here.
	/*stone's solution for lab3-B*/
	int32_t ret = -E_INVAL;
	switch (syscallno){
		case SYS_cputs:
			sys_cputs((char*)a1, a2);
			ret = 0;
			break;
		case SYS_cgetc:
			ret = sys_cgetc();
			break;
		case SYS_getenvid:
			ret = sys_getenvid();
			break;
		case SYS_env_destroy:
			ret = sys_env_destroy(a1);
			break;
		case SYS_map_kernel_page:
			ret = sys_map_kernel_page((void*)a1, (void*)a2);
			break;
		case SYS_sbrk:
			ret = sys_sbrk(a1);
			break;
		default:
			break;
	}
	return ret;
	//panic("syscall not implemented");
}
Exemple #2
0
// Dispatches to the correct kernel function, passing the arguments.
int32_t
syscall(uint32_t syscallno, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
{
	// Call the function corresponding to the 'syscallno' parameter.
	// Return any appropriate return value.
	// LAB 3: Your code here.
	int32_t ret = -E_INVAL;
	switch(syscallno) {
		case SYS_cputs:
			sys_cputs((char *)a1, a2);
			break;
		case SYS_cgetc:
			ret = sys_cgetc();
			break;
		case SYS_getenvid:
			ret = sys_getenvid();
			break;
		case SYS_env_destroy:
			ret = sys_env_destroy(a1);
			break;
		case SYS_yield:
			sys_yield();
			ret = 0;
			break;
		case SYS_map_kernel_page:
			ret = sys_map_kernel_page((void *)a1, (void *)a2);
			break;
		case SYS_sbrk:
			ret = sys_sbrk(a1);
			break;
		case SYS_exofork:
			ret = sys_exofork();
			break;
		case SYS_env_set_status:
			ret = sys_env_set_status(a1,a2);
			break;
		case SYS_page_alloc:
			ret = sys_page_alloc(a1,(void*)a2,a3);
			break;
		case SYS_page_map:
			ret = sys_page_map(a1,(void*)a2,a3,(void*)a4,a5);
			break;
		case SYS_page_unmap:
			ret = sys_page_unmap(a1,(void*)a2);
			break;
		case SYS_env_set_pgfault_upcall:
			ret = sys_env_set_pgfault_upcall(a1,(void*)a2);
			break;
		case SYS_ipc_try_send:
			ret = sys_ipc_try_send(a1,a2,(void*)a3,a4);
			break;
		case SYS_ipc_recv:
			ret = sys_ipc_recv((void*)a1);
	}
	return ret;
//	panic("syscall not implemented");
}
Exemple #3
0
// Dispatches to the correct kernel function, passing the arguments.
int32_t
syscall(uint32_t syscallno, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
{
	// Call the function corresponding to the 'syscallno' parameter.
	// Return any appropriate return value.
	// LAB 3: Your code here.
	switch (syscallno){
		case SYS_getenvid:
			return sys_getenvid();
		case SYS_cputs:
			sys_cputs((const char*)a1, a2);
			return 0;
		case SYS_cgetc:
			return sys_cgetc();
		case SYS_env_destroy:
			return sys_env_destroy(a1);
		case SYS_map_kernel_page:
			return sys_map_kernel_page((void*)a1, (void*)a2);
		case SYS_sbrk:
			return sys_sbrk(a1);
		case SYS_yield:
			sys_yield();
			return 0;
		case SYS_exofork:
			return sys_exofork();
		case SYS_env_set_status:
			return sys_env_set_status((envid_t)a1, (int)a2);
		case SYS_page_alloc:
			return sys_page_alloc((envid_t)a1, (void *)a2, 
						(int)a3);
		case SYS_page_map:
			return sys_page_map((envid_t)*((uint32_t*)a1),
					(void*)*((uint32_t*)a1+1), 
					(envid_t)*((uint32_t*)a1+2), 
					(void*)*((uint32_t*)a1+3), 
					(int)*((uint32_t*)a1+4));
		case SYS_page_unmap:
			return sys_page_unmap((envid_t)a1, (void*)a2);
		case SYS_env_set_priority:
			return sys_env_set_priority((envid_t)a1, (int) a2);
		case SYS_env_set_pgfault_upcall:
			return sys_env_set_pgfault_upcall((envid_t)a1,
						 (void*)a2);
		case SYS_ipc_recv:
			return sys_ipc_recv((void*)a1);
		case SYS_ipc_try_send:
			return sys_ipc_try_send((envid_t)a1, a2, 
						(void*)a3, (int)a4);
		default:
			return -E_INVAL;
	}
}
Exemple #4
0
ssize_t syscall_handler(uint32_t sys_nr, ...)
{
    ssize_t ret = -EINVAL;
    va_list vl;

    va_start(vl, sys_nr);

    switch(sys_nr)
    {
    case __NR_exit:
        sys_exit(va_arg(vl, uint32_t));
        ret = 0;
        break;
    case __NR_write: {
        int fd = va_arg(vl, int);
        const char* buf = va_arg(vl, const char*);
        size_t len = va_arg(vl, size_t);
        ret = sys_write(fd, buf, len);
        break;
    }
    //TODO: Currently, we ignore file descriptors
    case __NR_open:
    case __NR_close:
        ret = 0;
        break;
    case __NR_sbrk: {
        int incr = va_arg(vl, int);

        ret = sys_sbrk(incr);
        break;
    }
    default:
        kprintf("invalid system call: %u\n", sys_nr);
        ret = -ENOSYS;
        break;
    };

    va_end(vl);

    return ret;
}
/*
 * System call dispatcher.
 *
 * A pointer to the trapframe created during exception entry (in
 * exception-*.S) is passed in.
 *
 * The calling conventions for syscalls are as follows: Like ordinary
 * function calls, the first 4 32-bit arguments are passed in the 4
 * argument registers a0-a3. 64-bit arguments are passed in *aligned*
 * pairs of registers, that is, either a0/a1 or a2/a3. This means that
 * if the first argument is 32-bit and the second is 64-bit, a1 is
 * unused.
 *
 * This much is the same as the calling conventions for ordinary
 * function calls. In addition, the system call number is passed in
 * the v0 register.
 *
 * On successful return, the return value is passed back in the v0
 * register, or v0 and v1 if 64-bit. This is also like an ordinary
 * function call, and additionally the a3 register is also set to 0 to
 * indicate success.
 *
 * On an error return, the error code is passed back in the v0
 * register, and the a3 register is set to 1 to indicate failure.
 * (Userlevel code takes care of storing the error code in errno and
 * returning the value -1 from the actual userlevel syscall function.
 * See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
 *
 * Upon syscall return the program counter stored in the trapframe
 * must be incremented by one instruction; otherwise the exception
 * return code will restart the "syscall" instruction and the system
 * call will repeat forever.
 *
 * If you run out of registers (which happens quickly with 64-bit
 * values) further arguments must be fetched from the user-level
 * stack, starting at sp+16 to skip over the slots for the
 * registerized values, with copyin().
 */
void syscall(struct trapframe *tf) {
	int callno;
	int32_t retval;
	int err;

	KASSERT(curthread != NULL);
	KASSERT(curthread->t_curspl == 0);
	KASSERT(curthread->t_iplhigh_count == 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;


	off_t pos, new_pos;
	switch (callno) {
	case SYS_reboot:
		err = sys_reboot(tf->tf_a0);
		break;

	case SYS___time:
		err = sys___time((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1);
		break;

	case SYS_open:
		err = sys_open((userptr_t) tf->tf_a0, (int) tf->tf_a1,
				(int) tf->tf_a2, &retval);
		break;

	case SYS_read:
		err = sys_read((int) tf->tf_a0, (userptr_t) tf->tf_a1,
				(int) tf->tf_a2, &retval);
		break;

	case SYS_write:
		err = sys_write((int) tf->tf_a0, (userptr_t) tf->tf_a1,
				(int) tf->tf_a2, &retval);
		break;
	case SYS_lseek:

		pos = (((off_t)tf->tf_a2 << 32) | tf->tf_a3);
		err = sys_lseek((userptr_t) tf->tf_a0, pos,
				(userptr_t)(tf->tf_sp+16), &new_pos);

		if (err == 0)
		{
			retval = (int32_t)(new_pos >> 32);
			tf->tf_v1 = (int32_t)(new_pos & 0xFFFFFFFF);
		}


		break;

	case SYS_close:
		err = sys_close((userptr_t) tf->tf_a0, &retval);
		break;

	case SYS_dup2:
		err = sys_dup2((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1, &retval);
		break;

	case SYS_getpid:
		err = sys_getpid(&retval);
		break;
	case SYS_sbrk:
		err = sys_sbrk((userptr_t)tf->tf_a0, &retval);
		break;
	case SYS_fork:
		err = sys_fork(tf, &retval);
		break;
	case SYS_execv:
		err = sys_execv((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1, &retval);
		retval = 0;
		break;
	case SYS_waitpid:
		err = sys_waitpid((userptr_t) tf->tf_a0, (userptr_t) tf->tf_a1,
				(userptr_t) tf->tf_a2, &retval);
		break;
	case SYS__exit:
		//kprintf("TEMPPPP:Exit has been called!	\n");
		err = sys__exit((int) tf->tf_a0);
		break;
		/* Add stuff here */

	default:
		kprintf("Unknown syscall %d\n", callno);
		err = ENOSYS;
		break;
	}
Exemple #6
0
// Dispatches to the correct kernel function, passing the arguments.
int32_t
syscall(uint32_t syscallno, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
{
	// Call the function corresponding to the 'syscallno' parameter.
	// Return any appropriate return value.
	// LAB 3: Your code here.
	/*stone's solution for lab3-B*/
	int32_t ret = -E_INVAL;
	switch (syscallno){
		case SYS_cputs:
			sys_cputs((char*)a1, a2);
			ret = 0;
			break;
		case SYS_cgetc:
			ret = sys_cgetc();
			break;
		case SYS_getenvid:
			ret = sys_getenvid();
			break;
		case SYS_env_destroy:
			ret = sys_env_destroy(a1);
			break;
		case SYS_map_kernel_page:
			ret = sys_map_kernel_page((void*)a1, (void*)a2);
			break;
		case SYS_sbrk:
			ret = sys_sbrk(a1);
			break;
		/*stone's solution for lab4-A*/
		case SYS_yield:
			sys_yield();
			ret = 0;
			break;
		case SYS_exofork:
			ret = sys_exofork();
			break;
		case SYS_env_set_status:
			ret = sys_env_set_status(a1, a2);
			break;
		case SYS_env_set_pgfault_upcall:
			ret = sys_env_set_pgfault_upcall((envid_t)a1, (void*)a2);
			break;
		case SYS_page_alloc:
			ret = sys_page_alloc((envid_t)a1, (void*)a2, (int)a3);
			break;
		case SYS_page_map:
			/*stone: see lib/syscall.c for modification details*/
			ret = sys_page_map(*((uint32_t*)a1), (void*)*((uint32_t*)a1 + 1), *((uint32_t*)a1 + 2), (void*)*((uint32_t*)a1 + 3), *((uint32_t*)a1 + 4));
			//ret = sys_page_map(a1, (void*)a2, a3, (void*)a4, a5);
			break;
		case SYS_page_unmap:
			ret = sys_page_unmap(a1, (void*)a2);
			break;
		case SYS_ipc_recv:
			ret = sys_ipc_recv((void*)a1);
			break;
		case SYS_ipc_try_send:
			ret = sys_ipc_try_send((envid_t)a1, a2, (void*)a3, (int)a4);
			break;
		case SYS_env_set_trapframe:
			ret = sys_env_set_trapframe((envid_t)a1, (struct Trapframe*)a2);
			break;
		default:
			break;
	}
	return ret;
	//panic("syscall not implemented");
}
Exemple #7
0
/*
 * System call dispatcher.
 *
 * A pointer to the trapframe created during exception entry (in
 * exception-*.S) is passed in.
 *
 * The calling conventions for syscalls are as follows: Like ordinary
 * function calls, the first 4 32-bit arguments are passed in the 4
 * argument registers a0-a3. 64-bit arguments are passed in *aligned*
 * pairs of registers, that is, either a0/a1 or a2/a3. This means that
 * if the first argument is 32-bit and the second is 64-bit, a1 is
 * unused.
 *
 * This much is the same as the calling conventions for ordinary
 * function calls. In addition, the system call number is passed in
 * the v0 register.
 *
 * On successful return, the return value is passed back in the v0
 * register, or v0 and v1 if 64-bit. This is also like an ordinary
 * function call, and additionally the a3 register is also set to 0 to
 * indicate success.
 *
 * On an error return, the error code is passed back in the v0
 * register, and the a3 register is set to 1 to indicate failure.
 * (Userlevel code takes care of storing the error code in errno and
 * returning the value -1 from the actual userlevel syscall function.
 * See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
 *
 * Upon syscall return the program counter stored in the trapframe
 * must be incremented by one instruction; otherwise the exception
 * return code will restart the "syscall" instruction and the system
 * call will repeat forever.
 *
 * If you run out of registers (which happens quickly with 64-bit
 * values) further arguments must be fetched from the user-level
 * stack, starting at sp+16 to skip over the slots for the
 * registerized values, with copyin().
 */
void
syscall(struct trapframe *tf)
{
	int callno;
	int32_t retval;
	int err;

	KASSERT(curthread != NULL);
	KASSERT(curthread->t_curspl == 0);
	KASSERT(curthread->t_iplhigh_count == 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;

	int whence = 0;
    off_t position = 0;
	int32_t retval2 = 0; 

	switch (callno) {
	    case SYS_reboot:
		err = sys_reboot(tf->tf_a0);
		break;

	    case SYS___time:
		err = sys___time((userptr_t)tf->tf_a0,
				 (userptr_t)tf->tf_a1);
		break;

	    /* Add stuff here */
	    case SYS_write:
		err = sys_write((int)tf->tf_a0,(const void *)tf->tf_a1,(size_t)tf->tf_a2, &retval);
		break;

 		case SYS_read:
		err = sys_read(tf->tf_a0, (void *) tf->tf_a1, (size_t) tf->tf_a2, &retval);
		break;
		
		case SYS_open:
		err = sys_open((char *)tf->tf_a0, tf->tf_a1, (mode_t)tf->tf_a2, &retval);
		break;

		case SYS_close:
		err = sys_close(tf->tf_a0);
		break;

		case SYS_dup2:
		err = sys_dup2(tf->tf_a0, tf->tf_a1, &retval);
		break;

   	    case SYS_lseek:
    	position |= (off_t)tf->tf_a2;
    	position <<= 32;
    	position |= (off_t)tf->tf_a3;

    	err = copyin((const userptr_t)tf->tf_sp+16, &whence, sizeof(whence));
    	if (err)
    		break;
    	err = sys_lseek((int)tf->tf_a0, position, (int)whence, &retval, &retval2);
    	if(!err) 
			tf->tf_v1 = retval2;
   	    break;

		case SYS_fork:
		err = sys_fork(tf,&retval);
		break;

		case SYS_getpid:
		err = sys_getpid((pid_t *)&retval);
		break;
		case SYS_waitpid:
		  err = sys_waitpid((pid_t)tf->tf_a0, (userptr_t)tf->tf_a1, (int)tf->tf_a2, (pid_t *)&retval);
	  	break;

		case SYS__exit:
	  	sys__exit((int)tf->tf_a0);
	  	err = -1;
	  	//will never come here as it doesnt return
	  	break;
		
		case SYS_execv:
		err=sys_execv((const char *)tf->tf_a0,(char **)tf->tf_a1);
		break;

		case SYS_sbrk:
		err=(int)sys_sbrk((intptr_t)tf->tf_a0, (vaddr_t *)&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 */
	KASSERT(curthread->t_curspl == 0);
	/* ...or leak any spinlocks */
	KASSERT(curthread->t_iplhigh_count == 0);
}
Exemple #8
0
/*
 * System call dispatcher.
 *
 * A pointer to the trapframe created during exception entry (in
 * exception.S) is passed in.
 *
 * The calling conventions for syscalls are as follows: Like ordinary
 * function calls, the first 4 32-bit arguments are passed in the 4
 * argument registers a0-a3. 64-bit arguments are passed in *aligned*
 * pairs of registers, that is, either a0/a1 or a2/a3. This means that
 * if the first argument is 32-bit and the second is 64-bit, a1 is
 * unused.
 *
 * This much is the same as the calling conventions for ordinary
 * function calls. In addition, the system call number is passed in
 * the v0 register.
 *
 * On successful return, the return value is passed back in the v0
 * register, or v0 and v1 if 64-bit. This is also like an ordinary
 * function call, and additionally the a3 register is also set to 0 to
 * indicate success.
 *
 * On an error return, the error code is passed back in the v0
 * register, and the a3 register is set to 1 to indicate failure.
 * (Userlevel code takes care of storing the error code in errno and
 * returning the value -1 from the actual userlevel syscall function.
 * See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
 *
 * Upon syscall return the program counter stored in the trapframe
 * must be incremented by one instruction; otherwise the exception
 * return code will restart the "syscall" instruction and the system
 * call will repeat forever.
 *
 * If you run out of registers (which happens quickly with 64-bit
 * values) further arguments must be fetched from the user-level
 * stack, starting at sp+16 to skip over the slots for the
 * registerized values, with copyin().
 */
void
syscall(struct trapframe *tf)
{
	int callno;
	int32_t retval;
	int err = 0;

	KASSERT(curthread != NULL);
	KASSERT(curthread->t_curspl == 0);
	KASSERT(curthread->t_iplhigh_count == 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;

	    case SYS___time:
			err = sys___time((userptr_t)tf->tf_a0,
				 (userptr_t)tf->tf_a1);
			break;

	    /* Add stuff here */

	    case SYS_read:
			err = sys_read((int)tf->tf_a0,	// filehandle
				(void*)tf->tf_a1,	// buffer
				(size_t)tf->tf_a2,	// size
				&retval);		// return value
			break;

	    case SYS_write:
			err = sys_write((int)tf->tf_a0,	// filehandle
				(const void*)tf->tf_a1,	// buffer
				(size_t)tf->tf_a2,	// size
				&retval);		// return value
			break;

	    case SYS_open:
			err = sys_open((const char*)tf->tf_a0,	// filename
				(int)tf->tf_a1,		// flags
				&retval);		// return value
			break;

	    case SYS_close:
			err = sys_close((int)tf->tf_a0);	// filehandle
			break;

	    case SYS_dup2:
			err = sys_dup2((int)tf->tf_a0,		// old_filehandle
				(int)tf->tf_a1,		// new_filehandle
				&retval);		// return value
			break;

	   case SYS__exit:
			sys_exit((int)tf->tf_a0);	// exitcode
			break;

	   case SYS_getpid:
			retval = sys_getpid();	// exitcode
			break;
 
	   case SYS_waitpid:
			err = sys_waitpid((pid_t)tf->tf_a0, (int*)tf->tf_a1, tf->tf_a2, &retval);
			break;

	   case SYS_fork:
			err = sys_fork(tf, &retval);
			break;

	   case SYS_execv:
			err = sys_execv((userptr_t)tf->tf_a0, (userptr_t)tf->tf_a1);
			break;

		case SYS_sbrk:
			err = sys_sbrk((intptr_t)tf->tf_a0, &retval);
			break;
		
	    case SYS_lseek: {
			off_t offset = tf->tf_a2;
			offset = offset<<32;
			offset = offset|tf->tf_a3;


			int whence;
			int err_copyin = copyin((userptr_t)tf->tf_sp+16,&whence,sizeof(whence));

			if (err_copyin) {
				break;
			}

			off_t retoffset;
			err = sys_lseek((int)tf->tf_a0,	// filehandle
				offset,			// desired offset
				whence,
				&retoffset);		// return value

			if (!err) {
				retval = retoffset>>32;
				tf->tf_v1 = retoffset;
			}
			break;
	}	break;

	   case SYS___getcwd:
			err = sys___getcwd((char*)tf->tf_a0,	// buffer
				(size_t)tf->tf_a1,		// size
				&retval);			// return value
		break;

	   case SYS_chdir:
			err = sys_chdir((char*)tf->tf_a0);	// path
		break;

	    default:
			kprintf("Unknown syscall %d\n", callno);
			err = ENOSYS;
			break;
	}
Exemple #9
0
/* call functions based on the call number.  */
void
mips_syscall(struct trapframe *tf)
{
	int callno;
	int32_t retval;
	int err;

	assert(curspl==0);

	callno = tf->tf_v0; // the system call number is
 	//passed in the v0 register.

	/*
	 * 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;
		case SYS_execv:
		// err = sys_execv_(tf);
		err = sys_execv(tf->tf_a0, tf->tf_a1);
		break;
		case SYS_fork:
		err = sys_fork(tf, &retval);
		break;
		case SYS_waitpid:
		err = sys_waitpid(tf->tf_a0,tf->tf_a1, &retval);
		break;
		case SYS_getpid:
		err = sys_getpid(&retval);
		break;
		case SYS__exit:
		err = sys__exit(tf->tf_a0, &retval);
		break;
		case SYS_read:
		err = sys_read(tf, &retval);
		break;
		case SYS_write:
		// err = sys_write(tf, &retval);
		err = sys_write(tf->tf_a0, tf->tf_a1, tf->tf_a2, &retval);
		break;
		case SYS_sbrk:
		err = sys_sbrk(tf->tf_a0, &retval);
		break;
	    /* Add stuff here */
 
	    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);

}
/*
 * System call dispatcher.
 *
 * A pointer to the trapframe created during exception entry (in
 * exception-*.S) is passed in.
 *
 * The calling conventions for syscalls are as follows: Like ordinary
 * function calls, the first 4 32-bit arguments are passed in the 4
 * argument registers a0-a3. 64-bit arguments are passed in *aligned*
 * pairs of registers, that is, either a0/a1 or a2/a3. This means that
 * if the first argument is 32-bit and the second is 64-bit, a1 is
 * unused.
 *
 * This much is the same as the calling conventions for ordinary
 * function calls. In addition, the system call number is passed in
 * the v0 register.
 *
 * On successful return, the return value is passed back in the v0
 * register, or v0 and v1 if 64-bit. This is also like an ordinary
 * function call, and additionally the a3 register is also set to 0 to
 * indicate success.
 *
 * On an error return, the error code is passed back in the v0
 * register, and the a3 register is set to 1 to indicate failure.
 * (Userlevel code takes care of storing the error code in errno and
 * returning the value -1 from the actual userlevel syscall function.
 * See src/user/lib/libc/arch/mips/syscalls-mips.S and related files.)
 *
 * Upon syscall return the program counter stored in the trapframe
 * must be incremented by one instruction; otherwise the exception
 * return code will restart the "syscall" instruction and the system
 * call will repeat forever.
 *
 * If you run out of registers (which happens quickly with 64-bit
 * values) further arguments must be fetched from the user-level
 * stack, starting at sp+16 to skip over the slots for the
 * registerized values, with copyin().
 */
void
syscall(struct trapframe *tf)
{
	int callno;
	int32_t retval;
	int err;

	KASSERT(curthread != NULL);
	KASSERT(curthread->t_curspl == 0);
	KASSERT(curthread->t_iplhigh_count == 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;
		
		case SYS_open:
		{
			err = sys_open((const_userptr_t)tf->tf_a0, tf->tf_a1, tf->tf_a2, &retval);
			break;
		}

		case SYS_close:
		{
			err = sys_close(tf->tf_a0);
			break;
		
		}

	   
		case SYS_read:
		{
			err = sys_read(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2, &retval);
			break;
		
		}

	  
		case SYS_write:
		{
			err = sys_write(tf->tf_a0, (const userptr_t)tf->tf_a1, tf->tf_a2, &retval);
			break;		
		
		}


		case SYS_lseek:
		{
			// a little tricky, one of the inputs and the return value are 64 bits long.
			int fd = tf->tf_a0;
			off_t pos_left32 = tf->tf_a2;
			off_t pos_right32 = tf->tf_a3;
			//pos_left32 <<= 32; // pos_right32 is changing after this line . WTF !!! .. FOLLOW UP !!
			off_t left = pos_left32 << 32;
			//off_t pos = pos_left32 | pos_right32;
			off_t pos = left | pos_right32;
			int whence;
			err  = copyin((const userptr_t)tf->tf_sp+16, (void*)&whence, sizeof(int));
			if(err)
				break;

	
			off_t lseek_retval;		
			err = sys_lseek(fd, pos, whence, &lseek_retval);
			if(err)
				break;

			// check this. how does the value get copied
			retval = lseek_retval >> 32;
			off_t lseek_right32 = lseek_retval;


			lseek_right32 = lseek_right32  <<  32;
			lseek_right32 = lseek_right32 >> 32;

			tf->tf_v1 = lseek_right32;
			break;		
		
		}


		
		case SYS_dup2:
		{
			err = sys_dup2(tf->tf_a0, tf->tf_a1, &retval);
			break;
		
		
		}

		case SYS_chdir:
		{
			err = sys_chdir((const userptr_t)tf->tf_a0);
			break;
		}

		case SYS___getcwd:
		{

			err = sys_getcwd((userptr_t)tf->tf_a0, tf->tf_a1);
			break;
		}

		case SYS___time:
		err = sys___time((userptr_t)tf->tf_a0,
				 (userptr_t)tf->tf_a1);
		break;

	    /* Add stuff here */
        case SYS_fork:
            err = sys_fork(tf, &retval);
            break;

        case SYS_getpid:
            err = sys_getpid(&retval);
            break;
        case SYS__exit:
            err = sys__exit(tf->tf_a0);
            break;
        case SYS_waitpid:
            err = sys_waitpid(tf->tf_a0, (userptr_t)tf->tf_a1, tf->tf_a2, &retval);
            break;
        case SYS_execv:
            err = sys_execv((userptr_t)tf->tf_a0, (userptr_t *)tf->tf_a1);
            break;
        case SYS_sbrk:
        	err = sys_sbrk((intptr_t)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 */
	KASSERT(curthread->t_curspl == 0);
	/* ...or leak any spinlocks */
	KASSERT(curthread->t_iplhigh_count == 0);
}
Exemple #11
0
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);
}