161 lines
3.6 KiB
C
161 lines
3.6 KiB
C
/*
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*
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*static char frefsccsid[] = "@(#)fpu_probe.c 1.1 10/31/94 Copyright Sun Microsystems";
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*/
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#include "fpu.h"
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/*
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* File: fpu_probe.c Date: 4/22/88
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*
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* Function: To allow the FPU diagnostics to detect the presence and
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* type of Floating Point Co-processor.
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*
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* Routines: fpu_probe, and fpu_type
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*
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* History: 5/11/88 - Orig coding (BDS)
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* 6/27/88 - Updated fpu_bad_ti for New Improved TI
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*/
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/*
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* external functions required
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*/
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extern int get_fsr();
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extern int check_fpu();
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extern int fpu_present; /* Global T/F flag */
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extern unsigned long error_ok; /* Trap variables */
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extern unsigned long trap_flag; /* Trap variables */
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/*
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* Name: fpu_probe
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* Function: To detect the presence of a Floating Point Co-processor
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* and report it to the application level.
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* Returns: TRUE (0) if installed or FALSE (1) if not
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* Calling: if (fpu_probe())
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*/
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fpu_probe()
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{
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if (fpu_present > 1) { /* .. if unknown then read */
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if (check_fpu() == 0) { /* .... from kmem */
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fpu_present = 0; /* advise user that there is one */
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}
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fpu_present = 1; /* Advise user no fpu installed */
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}
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return(fpu_present); /* return the flag to caller */
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}
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/* */
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/*
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* Name: fpu_type
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* Function: Identifies the type of Floating Point Co-processor installed
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* in the system.
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* Returns: See table below
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* Convention: if (fpu_type() == WEITEK)
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*
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*/
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/*
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* The FPU type is encoded in the status register bits 17 and 18. The
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* meaning is shown below.
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*
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* 31 16 0
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* | | |
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* FSR [....|....|....|.xx.|....|....|....|....]
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* 00 = Weitek
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* 01 = FAB6
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* 10 = TI8847
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* 11 = Invalid
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*/
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fpu_type()
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{
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unsigned long status_reg;
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int device;
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device = INVALID;
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if (fpu_probe() == 0) { /* see if any present */
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status_reg = get_fsr(); /* get FPU Status reg */
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status_reg = (status_reg >> 17); /* set up bits 17&18 */
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switch(status_reg & 0x3) { /* isolate valid bits */
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case 0 : device = WEITEK; /* return Weitek code */
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break;
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case 1 : device = FAB6; /* return FAB6 code */
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break;
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case 2 : device = TI8847; /* return TI8847 code */
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break;
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/************************
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* Add new devices here *
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************************/
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default: device = INVALID; /* return invalid code */
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}
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}
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return(device); /* Advise device type */
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}
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/***************************************************************************
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* Special situation test function
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***************************************************************************
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*
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* A problem has been identified with the TI8847 processor that can
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* be detected by preforming the following step. If the result is not
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* equal to 0 then the device is the bad one.
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* See Cassy Ng (ex 2248) for details.
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*
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* 4026531840.0 = 0xF0000000 (64 bits)
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*
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* if ( ( fdtoi(4026531840) == 0x7fffffff ) && ( Overflow_Trap ) )
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* then FPU ok
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* else FPU bad (ie.. Old Type of TI with BUG)
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*/
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fpu_badti()
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{
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unsigned long result;
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result = float_int_d(4026531840.0);
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if ( result == 0x7fffffff ) {
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return(0);
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}
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return(1);
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}
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/*
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* Simple FPU processor type calls
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*
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* These two calls are designed for a routine that simply wants
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* to do an if - then function
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*
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*/
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fpu_is_weitek()
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{
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if (fpu_type() == WEITEK) {
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return(1);
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}
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return(0);
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}
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fpu_is_ti8847()
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{
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if (fpu_type() == TI8847) {
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return(1);
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}
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return(0);
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}
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fpu_is_fab6()
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{
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if (fpu_type() == FAB6) {
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return(1);
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}
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return(0);
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}
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fpu_is_invalid()
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{
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if (fpu_type() == INVALID) {
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return(1);
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}
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return(0);
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}
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