add directory study

study/sabre/os/files/Processors/COPRO.ASM

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+comment *
+   Purpose:
+   To detect math coprocessor type (8087, 287, 387) and manufacturer
+   (Intel, IIT)
+*
+
+        .model  tiny
+
+        .data
+        fnone   equ     0
+        f8087   equ     1
+        f80287  equ     2
+        f80387  equ     3
+        funk    equ     0FFh
+        ndp_cw  dw      ?
+        ndp_sw  dw      ?
+        mNDPCW  dw      ?
+        mndp    db      ?
+        ndpmsg  db      "Math coprocessor found: $"
+        manmsg  db      "Manufacturer: $"
+        _87     db      "8087",13,10,"$"
+        _287    db      "80287",13,10,"$"
+        _387    db      "80387 or i486",13,10,"$"
+        _funk   db      "What the hell kind of a copro is this?",13,10,"$"
+        Intel   db      "Intel or clone",13,10,"$"
+        IIT     db      "IIT or clone",13,10,"$"
+
+        .code
+        org     100h
+
+start:
+
+; The next two 80x87 instructions cannot carry the WAIT prefix,
+; because there may not be an 80x87 for which to wait.  The WAIT is
+; therefore emulated with a MOV CX,<value>! LOOP $ combination.
+
+.8087
+        mov     word ptr ndp_cw,0000H
+        cli                     ;no interrupts during this test
+
+        fninit                  ;initialize NDP
+        mov     cx,2
+        loop    $
+
+        fnstcw  ndp_cw          ;store control word in ndp_cw
+;        mov     cx,14h
+;        loop    $
+
+        sti
+        mov     ax,ndp_cw       ;check for valid status word
+        cmp     ah,3            ;is NDP present?
+        je      short ndp_01    ;if 3, must be there
+        mov     mNDP,fnone
+        jmp     short ndp_done
+
+ndp_01:
+        cmp     ax,03FFH        ;check if 8087
+        jne     short ndp_02
+        mov     mNDP,f8087
+        jmp     short ndp_04
+
+ndp_02:
+        call    iit_test
+
+.286P
+        cmp     ax,037FH        ;check if 286/387/486
+        jne     short ndp_05    ;must be garbage
+
+;detect 287 or 387
+
+        fld1                    ;Load +1.0 onto NDP stack
+        fldz                    ;Load +0.0 onto NDP stack
+        fdiv                    ;do +1/0
+        fld1                    ;Load +1.0 onto NDP stack
+        fchs                    ;Change to -1.0
+        fldz                    ;Load +0.0 onto NDP stack
+        fdiv                    ;do -1/0
+        fcom                    ;compare
+        fstsw   ndp_sw
+        mov     ax,ndp_sw
+        and     ah,41H          ; C3, C0
+        cmp     ah,40H          ; ST(0) = ST(1)
+        jne     short ndp_03
+        mov     mNDP,f80287
+        jmp     short ndp_04
+
+ndp_03:
+        cmp     ah,01H          ; ST(0) < ST(1)
+        jne     short ndp_05
+        mov     mNDP,f80387
+
+ndp_04:
+
+.8087
+        fstcw   mNDPCW          ;save status for INFOPLUS
+        jmp     short ndp_done
+
+ndp_05:
+        mov     mNDP,funk
+
+ndp_done:
+        mov     ah, 9
+        mov     dx, offset manmsg
+        int     21h
+        cmp     [mman], 1       ;IIT=1?
+        jne     short intelman
+        mov     ah, 9
+        mov     dx, offset iit
+        int     21h
+        jmp     short type_msgs
+
+intelman:
+        mov     ah, 9
+        mov     dx, offset intel
+        int     21h
+
+type_msgs:
+        mov     ah, 9
+        mov     dx, offset ndpmsg
+        int     21h
+        cmp     [mndp], 0FFh
+        jne     short not_funk
+        mov     ah, 9
+        mov     dx, offset _funk
+        int     21h
+        jmp     short exit_prog
+
+not_funk:
+        cmp     [mndp], 3
+        jne     short not_387
+        mov     ah, 9
+        mov     dx, offset _387
+        int     21h
+        jmp     short exit_prog
+
+not_387:
+        cmp     [mndp], 2
+        jne     short not_287
+        mov     ah, 9
+        mov     dx, offset _287
+        int     21h
+        jmp     short exit_prog
+
+not_287:
+        mov     ah, 9
+        mov     dx, offset _87
+        int     21h
+exit_prog:
+        mov     al, [mndp]
+        mov     ah, 4ch
+        int     21h
+
+iit_test        proc    near
+
+        .data
+        fsb0    equ     <dw 0E8DBh>     ;bank 0 opcode
+        fsb1    equ     <dw 0EBDBh>     ;bank 1 opcode
+        fsb2    equ     <dw 0EADBh>     ;bank 2 opcode
+        f4x4    equ     <dw 0F1DBh>     ;4x4 mat transform opcode
+        f0      dd      9.9999
+        f1      dd      10.0
+        mman    db      0       ;assume Intel=0 installed initially
+
+        .code
+        ;initialize two banks to zero
+        wait
+        fsb0            ;switch to bank 0, default on Intel
+        finit
+        fsb1            ;switch to bank 1
+        finit
+        ;store a 2.0 into bank 0 while placing a 1.0 into bank 1
+        fsb0            ;switch to bank 0
+        fld     [f0]    ;load value from [F2] into bank 0 stack
+        fclex           ;clear all math copro exceptions
+
+        fsb1            ;switch to bank 1, should fail on Intel
+        fld     [f1]    ;load a 1 into bank 1 stack
+        fclex
+
+        fsb0
+        fcom    [f0]    ;compare, should be false on Intel
+        fclex
+
+        push    ax
+        .286p           ;FNSTSW AX only works on 287+
+        fnstsw  ax      ;store stat word in AX
+        sahf            ;transfer copro flags to CPU flags
+        ja      short is_intel
+        mov     [mman], 1       ;IIT=1, Intel=0 (default)
+
+is_intel:
+        finit           ;reset to original
+        pop     ax
+        ret
+        endp
+        end     start
+
+
+iit_test        proc    near
+
+        .data
+        fsb0    equ     <dw 0E8DBh>     ;bank 0 opcode
+        fsb1    equ     <dw 0EBDBh>     ;bank 1 opcode
+        fsb2    equ     <dw 0EADBh>     ;bank 2 opcode
+        f4x4    equ     <dw 0F1DBh>     ;4x4 mat transform opcode
+        f0      dd      9.9999
+        f1      dd      10.0
+        mman    db      0       ;assume Intel=0 installed initially
+
+        .code
+        ;initialize two banks to zero
+        wait
+        fsb0            ;switch to bank 0, default on Intel
+        finit
+        fsb1            ;switch to bank 1
+        finit
+        ;store a 2.0 into bank 0 while placing a 1.0 into bank 1
+        fsb0            ;switch to bank 0
+        fld     [f0]    ;load value from [F2] into bank 0 stack
+        fclex           ;clear all math copro exceptions
+
+        fsb1            ;switch to bank 1, should fail on Intel
+        fld     [f1]    ;load a 1 into bank 1 stack
+        fclex
+
+        fsb0
+        fcom    [f0]    ;compare, should be false on Intel
+        fclex
+
+        push    ax
+        .286p           ;FNSTSW AX only works on 287+
+        fnstsw  ax      ;store stat word in AX
+        sahf            ;transfer copro flags to CPU flags
+        ja      short is_intel
+        mov     [mman], 1       ;IIT=1, Intel=0 (default)
+
+is_intel:
+        finit           ;reset to original
+        pop     ax
+        ret
+        endp
+        end     start
+
+; EOF COPRO.ASM

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