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/* Copyright (C) 2004 David Decotigny
Copyright (C) 1999 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#include "idt.h"
#include "irq.h"
#include "exception.h"
/* array of exception wrappers, defined in exception_wrappers.S */
extern sos_vaddr_t sos_exception_wrapper_array[SOS_EXCEPT_NUM];
/* arrays of exception handlers, shared with exception_wrappers.S */
sos_exception_handler_t sos_exception_handler_array[SOS_EXCEPT_NUM] =
{ NULL, };
sos_ret_t sos_exceptions_setup(void)
{
/* We inidicate that the double fault exception handler is defined,
and give its address. this handler is a do-nothing handler (see
exception_wrappers.S), and it can NOT be overriden by the
functions below */
return sos_idt_set_handler(SOS_EXCEPT_BASE + SOS_EXCEPT_DOUBLE_FAULT,
(sos_vaddr_t) sos_exception_wrapper_array[SOS_EXCEPT_DOUBLE_FAULT],
0 /* CPL0 routine */);
}
sos_ret_t sos_exception_set_routine(int exception_number,
sos_exception_handler_t routine)
{
sos_ret_t retval;
sos_ui32_t flags;
if ((exception_number < 0) || (exception_number >= SOS_EXCEPT_NUM))
return -SOS_EINVAL;
/* Double fault not supported */
if (exception_number == SOS_EXCEPT_DOUBLE_FAULT)
return -SOS_ENOSUP;
sos_disable_IRQs(flags);
retval = SOS_OK;
/* Set the exception routine to be called by the exception wrapper */
sos_exception_handler_array[exception_number] = routine;
/* If the exception is to be enabled, update the IDT with the exception
wrapper */
if (routine != NULL)
retval
= sos_idt_set_handler(SOS_EXCEPT_BASE + exception_number,
(sos_vaddr_t) sos_exception_wrapper_array[exception_number],
0 /* CPL0 routine */);
else /* Disable the IDT entry */
retval
= sos_idt_set_handler(SOS_EXCEPT_BASE + exception_number,
(sos_vaddr_t)NULL /* No routine => disable IDTE */,
0 /* don't care */);
sos_restore_IRQs(flags);
return retval;
}
sos_exception_handler_t sos_exception_get_routine(int exception_number)
{
if ((exception_number < 0) || (exception_number >= SOS_EXCEPT_NUM))
return NULL;
/* Double fault not supported */
if (exception_number == SOS_EXCEPT_DOUBLE_FAULT)
return NULL;
/* Expected to be atomic */
return sos_exception_handler_array[exception_number];
}
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