/* Copyright (C) 2004 David Decotigny
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 <sos/assert.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, };
/* List of exception names for the x86 architecture */
static const char * sos_x86_exnames[] = {
[SOS_EXCEPT_DIVIDE_ERROR] = "Division by zero",
[SOS_EXCEPT_DEBUG] = "Debug",
[SOS_EXCEPT_NMI_INTERRUPT] = "Non Maskable Interrupt",
[SOS_EXCEPT_BREAKPOINT] = "Breakpoint",
[SOS_EXCEPT_OVERFLOW] = "Overflow",
[SOS_EXCEPT_BOUND_RANGE_EXCEDEED] = "Bound Range Exceeded",
[SOS_EXCEPT_INVALID_OPCODE] = "Invalid Opcode",
[SOS_EXCEPT_DEVICE_NOT_AVAILABLE] = "Device Unavailable",
[SOS_EXCEPT_DOUBLE_FAULT] = "Double Fault",
[SOS_EXCEPT_COPROCESSOR_SEGMENT_OVERRUN] = "Coprocessor Segment Overrun",
[SOS_EXCEPT_INVALID_TSS] = "Invalid TSS",
[SOS_EXCEPT_SEGMENT_NOT_PRESENT] = "Segment Not Present",
[SOS_EXCEPT_STACK_SEGMENT_FAULT] = "Stack Segfault",
[SOS_EXCEPT_GENERAL_PROTECTION] = "General Protection",
[SOS_EXCEPT_PAGE_FAULT] = "Page Fault",
[SOS_EXCEPT_INTEL_RESERVED_1] = "INTEL1",
[SOS_EXCEPT_FLOATING_POINT_ERROR] = "FP Error",
[SOS_EXCEPT_ALIGNEMENT_CHECK] = "Alignment Check",
[SOS_EXCEPT_MACHINE_CHECK] = "Machine Check",
[SOS_EXCEPT_INTEL_RESERVED_2] = "INTEL2",
[SOS_EXCEPT_INTEL_RESERVED_3] = "INTEL3",
[SOS_EXCEPT_INTEL_RESERVED_4] = "INTEL4",
[SOS_EXCEPT_INTEL_RESERVED_5] = "INTEL5",
[SOS_EXCEPT_INTEL_RESERVED_6] = "INTEL6",
[SOS_EXCEPT_INTEL_RESERVED_7] = "INTEL7",
[SOS_EXCEPT_INTEL_RESERVED_8] = "INTEL8",
[SOS_EXCEPT_INTEL_RESERVED_9] = "INTEL9",
[SOS_EXCEPT_INTEL_RESERVED_10] = "INTEL10",
[SOS_EXCEPT_INTEL_RESERVED_11] = "INTEL11",
[SOS_EXCEPT_INTEL_RESERVED_12] = "INTEL12",
[SOS_EXCEPT_INTEL_RESERVED_13] = "INTEL13",
[SOS_EXCEPT_INTEL_RESERVED_14] = "INTEL14"
};
/* Catch-all exception handler */
static void sos_generic_ex(int exid, const struct sos_cpu_state *ctxt)
{
const char *exname = sos_exception_get_name(exid);
sos_display_fatal_error("Exception %s in Kernel at instruction 0x%x (info=%x)!\n",
exname,
sos_cpu_context_get_PC(ctxt),
(unsigned)sos_cpu_context_get_EX_info(ctxt));
}
sos_ret_t sos_exception_subsystem_setup(void)
{
sos_ret_t retval;
int exid;
/* Setup the generic exception handler by default for everybody
except for the double fault exception */
for (exid = 0 ; exid < SOS_EXCEPT_NUM ; exid ++)
{
/* Skip double fault (see below) */
if (exid == SOS_EXCEPT_DOUBLE_FAULT)
continue;
retval = sos_exception_set_routine(exid, sos_generic_ex);
if (SOS_OK != retval)
return retval;
}
/* 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];
}
const char * sos_exception_get_name(int exception_number)
{
if ((exception_number < 0) || (exception_number >= SOS_EXCEPT_NUM))
return NULL;
return sos_x86_exnames[exception_number];
}
