/*[
c_xcptn.c
LOCAL CHAR SccsID[]="@(#)c_xcptn.c 1.14 01/31/95";
Exception Handling Support.
---------------------------
]*/
#include <stdio.h>
#include <insignia.h>
#include <host_def.h>
#include StringH
#include <xt.h>
#include <c_main.h>
#include <c_addr.h>
#include <c_bsic.h>
#include <c_prot.h>
#include <c_seg.h>
#include <c_stack.h>
#include <c_xcptn.h>
#include <c_reg.h>
#include <c_intr.h>
#include <c_xtrn.h>
#include <ccpupig.h>
#include <fault.h>
/*
Allow print out of exceptions or disallow it.
*/
GLOBAL BOOL show_exceptions = FALSE;
GLOBAL BOOL trap_exceptions = FALSE;
LOCAL BOOL first_exception = TRUE;
#define check_exception_env() \
{ \
IMPORT char *host_getenv IPT1 (char *, name); \
if (first_exception) \
{ \
char *env = host_getenv ("CCPU_SHOW_EXCEPTIONS"); \
if (env != NULL) \
{ \
show_exceptions = TRUE; \
if (strcasecmp(env, "TRAP") == 0) \
trap_exceptions = TRUE; \
} \
} \
first_exception = FALSE; \
}
IMPORT FILE *trace_file;
IMPORT IBOOL took_absolute_toc;
/*
Intel interrupt(exception) numbers.
*/
#define I0_INT_NR 0
#define I1_INT_NR 1
#define I5_INT_NR 5
#define I6_INT_NR 6
#define I7_INT_NR 7
#define I16_INT_NR 16
#define DF_INT_NR 8
#define GP_INT_NR 13
#define NP_INT_NR 11
#define PF_INT_NR 14
#define SF_INT_NR 12
#define TS_INT_NR 10
#define NULL_ERROR_CODE (IU16)0
/*
Intel IDT Error Code format.
*/
#define IDT_VECTOR_MASK 0xff
#define IDT_VECTOR_SHIFT 3
#define IDT_INDICATOR_BIT 2
/*
Interrupt/Fault Status.
*/
GLOBAL BOOL doing_contributory;
GLOBAL BOOL doing_page_fault;
GLOBAL BOOL doing_double_fault;
GLOBAL BOOL doing_fault; /* true: FAULT, false: TRAP or ABORT */
GLOBAL ISM32 EXT; /* external/internal source */
GLOBAL IU32 CCPU_save_EIP; /* IP at start of instruction */
/*
Prototype our internal functions.
*/
LOCAL VOID check_for_double_fault IPT1(IU16, xcode);
LOCAL VOID check_for_shutdown IPT1(IU16, xcode);
LOCAL VOID benign_exception IPT3( ISM32, nmbr, ISM32, source, IU16, xcode);
LOCAL VOID contributory_exception IPT3( IU16, selector, ISM32, nmbr, IU16, xcode);
LOCAL VOID contributory_idt_exception IPT3( IU16, vector, ISM32, nmbr, IU16, xcode);
LOCAL char *faultstr IPT1(ISM32, nmbr );
/*
=====================================================================
INTERNAL ROUTINES START HERE.
=====================================================================
*/
LOCAL char *faultstr IFN1(ISM32, nmbr )
{
char *faulttable[] =
{
"DIV", "DBG", "NMI", "BPT",
"OVF", "BND", "OPC", "NAV",
"DF", "9", "TSS", "NP", "SF",
"GP", "PF", "15", "FPE", "ALN"
};
SAVED char buf[4];
if (nmbr > 16)
{
sprintf(buf, "%d", nmbr);
return buf;
}
else
return faulttable[nmbr];
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Determine if things are so bad we need a double fault. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
LOCAL VOID
check_for_double_fault IFN1( IU16, xcode)
{
if ( doing_contributory || doing_page_fault )
DF(xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Determine if things are so bad we need to close down. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
LOCAL VOID check_for_shutdown IFN1(IU16, xcode)
{
if ( doing_double_fault )
{
doing_contributory = FALSE;
doing_page_fault = FALSE;
doing_double_fault = FALSE;
EXT = INTERNAL;
/* force a reset - see schematic for AT motherboard */
c_cpu_reset();
#ifdef PIG
save_last_xcptn_details("Exception:- Shutdown @%2d\n", xcode, 0, 0, 0, 0);
ccpu_synch_count++;
pig_cpu_action = CHECK_ALL;
c_cpu_unsimulate();
#endif /* PIG */
/* then carry on */
c_cpu_continue(); /* DOES NOT RETURN */
}
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Handle Benign Exception */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
LOCAL VOID
benign_exception
IFN3(
ISM32, nmbr, /* exception number */
ISM32, source, /* internal/external interrupt cause */
IU16, xcode /* insignia exception code */
)
{
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) nmbr, NULL_ERROR_CODE))
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
EXT = source;
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- #%s-%d @%2d \n", (IUH)faultstr(nmbr), nmbr, xcode, 0, 0);
#endif /* PIG */
if (show_exceptions){
fprintf(trace_file, "(%04x:%08x)Exception:- %d.\n",
GET_CS_SELECTOR(), GET_EIP(), nmbr);
if (trap_exceptions) force_yoda();
}
took_absolute_toc = TRUE;
do_intrupt((IU16)nmbr, FALSE, FALSE, NULL_ERROR_CODE);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Handle Contributory Exception */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
LOCAL VOID
contributory_exception
IFN3(
IU16, selector, /* failing selector */
ISM32, nmbr, /* exception number */
IU16, xcode /* insignia exception code */
)
{
IU16 error_code;
/* check if exception caused by external caller */
check_interface_active(nmbr);
check_for_shutdown(xcode);
check_for_double_fault(xcode);
doing_contributory = TRUE;
error_code = (selector & 0xfffc) | EXT;
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) nmbr, (IS32)error_code))
doing_contributory = FALSE;
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
EXT = INTERNAL;
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- #%s-%d(%04x) @%2d\n", (IUH)faultstr(nmbr), nmbr, error_code, xcode, 0);
#endif /* PIG */
if (show_exceptions){
fprintf(trace_file, "(%04x:%08x)Exception:- %d(%04x).\n",
GET_CS_SELECTOR(), GET_EIP(), nmbr, error_code);
if (trap_exceptions) force_yoda();
}
took_absolute_toc = TRUE;
do_intrupt((IU16)nmbr, FALSE, TRUE, error_code);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Handle Contributory Exception (Via IDT). */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
LOCAL VOID
contributory_idt_exception
IFN3(
IU16, vector, /* failing interrupt vector */
ISM32, nmbr, /* exception number */
IU16, xcode /* insignia exception code */
)
{
IU16 error_code;
/* check if exception caused by external caller */
check_interface_active(nmbr);
check_for_shutdown(xcode);
check_for_double_fault(xcode);
doing_contributory = TRUE;
error_code = ((vector & IDT_VECTOR_MASK) << IDT_VECTOR_SHIFT)
| IDT_INDICATOR_BIT
| EXT;
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) nmbr, (IS32)error_code))
doing_contributory = FALSE;
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
EXT = INTERNAL;
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- %s-%d(%04x) @%2d\n", (IUH)faultstr(nmbr), nmbr, error_code, xcode, 0);
#endif /* PIG */
if (show_exceptions){
if ( GET_IDT_LIMIT() != 0 ){
fprintf(trace_file, "(%04x:%08x)Exception:- %d(%04x).\n",
GET_CS_SELECTOR(), GET_EIP(), nmbr, error_code);
if (trap_exceptions) force_yoda();
}
}
took_absolute_toc = TRUE;
do_intrupt((IU16)nmbr, FALSE, TRUE, error_code);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*
=====================================================================
EXTERNAL ROUTINES START HERE.
=====================================================================
*/
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Interrupt Table Too Small/Double Fault Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
DF
IFN1(
IU16, xcode /* insignia exception code */
)
{
doing_fault = FALSE;
if ( GET_PE() == 1 )
{
check_for_shutdown(xcode);
doing_double_fault = TRUE;
}
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) DF_INT_NR, (IS32)NULL_ERROR_CODE))
doing_double_fault = FALSE;
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
EXT = INTERNAL;
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- #DF-8 @%2d\n", xcode, 0, 0, 0, 0);
#endif /* PIG */
if (show_exceptions){
if ( GET_IDT_LIMIT() != 0 ){
fprintf(trace_file, "(%04x:%08x)Exception:- %d.\n",
GET_CS_SELECTOR(), GET_EIP(), DF_INT_NR);
if (trap_exceptions) force_yoda();
}
}
took_absolute_toc = TRUE;
do_intrupt((IU16)DF_INT_NR, FALSE, TRUE, NULL_ERROR_CODE);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* General Protection Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID GP IFN2( IU16, selector, IU16, xcode)
{
doing_fault = TRUE;
contributory_exception(selector, GP_INT_NR, xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* General Protection Exception. (Via IDT) */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID GP_INT IFN2( IU16, vector, IU16, xcode)
{
doing_fault = TRUE;
contributory_idt_exception(vector, GP_INT_NR, xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Divide Error Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID Int0 IFN0 ()
{
doing_fault = TRUE;
if ( GET_PE() == 1 )
{
doing_contributory = TRUE;
}
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) I0_INT_NR, (IS32)NULL_ERROR_CODE))
doing_fault = FALSE;
doing_contributory = FALSE;
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
EXT = INTERNAL;
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- #DIV-0\n", 0, 0, 0, 0, 0);
#endif /* PIG */
if (show_exceptions){
fprintf(trace_file, "(%04x:%08x)Exception:- %d.\n",
GET_CS_SELECTOR(), GET_EIP(), I0_INT_NR);
if (trap_exceptions) force_yoda();
}
took_absolute_toc = TRUE;
do_intrupt((IU16)I0_INT_NR, FALSE, FALSE, NULL_ERROR_CODE);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Single Step Exception. (FAULT) */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int1_f()
{
doing_fault = TRUE;
benign_exception(I1_INT_NR, EXTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Single Step Exception. (TRAP) */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int1_t()
{
doing_fault = FALSE;
benign_exception(I1_INT_NR, EXTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Bounds Check Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int5()
{
doing_fault = TRUE;
benign_exception(I5_INT_NR, INTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Invalid Opcode Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int6()
{
doing_fault = TRUE;
benign_exception(I6_INT_NR, INTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* NPX Not Available Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int7()
{
doing_fault = TRUE;
benign_exception(I7_INT_NR, INTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* NPX Error Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
Int16()
{
doing_fault = TRUE;
benign_exception(I16_INT_NR, EXTERNAL, -1);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Not Present Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID NP IFN2( IU16, selector, IU16, xcode)
{
doing_fault = TRUE;
contributory_exception(selector, NP_INT_NR, xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Not Present Exception. (Via IDT) */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
NP_INT
IFN2(
IU16, vector,
IU16, xcode
)
{
doing_fault = TRUE;
contributory_idt_exception(vector, NP_INT_NR, xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Page Fault Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
PF
IFN2(
IU16, page_error, /* correctly formatted page fault error code */
IU16, xcode
)
{
/* check if exception caused by external caller */
check_interface_active(PF_INT_NR);
doing_fault = TRUE;
check_for_shutdown(xcode);
/* Check for double page fault */
if ( doing_page_fault )
DF(xcode);
doing_page_fault = TRUE;
SET_EIP(CCPU_save_EIP);
#ifdef NTVDM
{
extern BOOL host_exint_hook IPT2(IS32, exp_no, IS32, error_code);
if(GET_PE() && host_exint_hook((IS32) PF_INT_NR, (IS32)page_error))
doing_fault = FALSE;
doing_page_fault = FALSE;
c_cpu_continue(); /* DOES NOT RETURN */
}
#endif
/* Set default mode up */
SET_OPERAND_SIZE(GET_SR_AR_X(CS_REG));
SET_ADDRESS_SIZE(GET_SR_AR_X(CS_REG));
SET_POP_DISP(0);
check_exception_env();
#ifdef PIG
save_last_xcptn_details("Exception:- #PF-14(%04x) CR2=%08x @%2d\n", page_error, GET_CR(CR_PFLA), xcode, 0, 0);
#endif /* PIG */
if (show_exceptions){
fprintf(trace_file, "(%04x:%08x)Exception:- %d(%04x) CR2=%08x.\n",
GET_CS_SELECTOR(), GET_EIP(), PF_INT_NR, page_error, GET_CR(CR_PFLA));
if (trap_exceptions) force_yoda();
}
took_absolute_toc = TRUE;
do_intrupt((IU16)PF_INT_NR, FALSE, TRUE, page_error);
c_cpu_continue(); /* DOES NOT RETURN */
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Stack Fault Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
SF
IFN2(
IU16, selector,
IU16, xcode
)
{
doing_fault = TRUE;
contributory_exception(selector, SF_INT_NR, xcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/* Task Switch Exception. */
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
GLOBAL VOID
TS
IFN2(
IU16, selector,
IU16, xcode
)
{
doing_fault = TRUE;
contributory_exception(selector, TS_INT_NR, xcode);
}
