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1623 |
jcastillo |
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| skeleton.sa 3.2 4/26/91
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| This file contains code that is system dependent and will
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| need to be modified to install the FPSP.
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| Each entry point for exception 'xxxx' begins with a 'jmp fpsp_xxxx'.
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| Put any target system specific handling that must be done immediately
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| before the jump instruction. If there no handling necessary, then
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| the 'fpsp_xxxx' handler entry point should be placed in the exception
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| table so that the 'jmp' can be eliminated. If the FPSP determines that the
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| exception is one that must be reported then there will be a
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| return from the package by a 'jmp real_xxxx'. At that point
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| the machine state will be identical to the state before
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| the FPSP was entered. In particular, whatever condition
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| that caused the exception will still be pending when the FPSP
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| package returns. Thus, there will be system specific code
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| to handle the exception.
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| If the exception was completely handled by the package, then
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| the return will be via a 'jmp fpsp_done'. Unless there is
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| OS specific work to be done (such as handling a context switch or
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| interrupt) the user program can be resumed via 'rte'.
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| In the following skeleton code, some typical 'real_xxxx' handling
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| code is shown. This code may need to be moved to an appropriate
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| place in the target system, or rewritten.
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| Copyright (C) Motorola, Inc. 1990
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| All Rights Reserved
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| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
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| The copyright notice above does not evidence any
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| actual or intended publication of such source code.
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| Modified for Linux-1.3.x by Jes Sorensen (jds@kom.auc.dk)
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#include
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|SKELETON idnt 2,1 | Motorola 040 Floating Point Software Package
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|section 15
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| The following counters are used for standalone testing
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sigunimp: .long 0
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sigbsun: .long 0
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siginex: .long 0
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sigdz: .long 0
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sigunfl: .long 0
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sigovfl: .long 0
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sigoperr: .long 0
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sigsnan: .long 0
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sigunsupp: .long 0
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|section 8
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.include "fpsp.h"
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LOFF_ORIG_D0 = 0x20
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#define SAVE_ALL \
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clrl %sp@-; /* stk_adj */ \
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movel %d0,%sp@-; /* orig d0 */ \
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movel %d0,%sp@-; /* d0 */ \
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moveml %d1-%d5/%a0-%a1,%sp@-
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|xref b1238_fix
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| Divide by Zero exception
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| All dz exceptions are 'real', hence no fpsp_dz entry point.
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.global dz
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.global real_dz
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dz:
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real_dz:
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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bclrb #E1,E_BYTE(%a6)
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frestore (%sp)+
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unlk %a6
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addl #1,sigdz |for standalone testing
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| signifies that the stack frame
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| is NOT for syscall
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movel %sp,%sp@- | stack frame pointer argument
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| Inexact exception
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| All inexact exceptions are real, but the 'real' handler
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| will probably want to clear the pending exception.
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| The provided code will clear the E3 exception (if pending),
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| otherwise clear the E1 exception. The frestore is not really
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| necessary for E1 exceptions.
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| Code following the 'inex' label is to handle bug #1232. In this
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| bug, if an E1 snan, ovfl, or unfl occurred, and the process was
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| swapped out before taking the exception, the exception taken on
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| return was inex, rather than the correct exception. The snan, ovfl,
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| and unfl exception to be taken must not have been enabled. The
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| fix is to check for E1, and the existence of one of snan, ovfl,
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| or unfl bits set in the fpsr. If any of these are set, branch
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| to the appropriate handler for the exception in the fpsr. Note
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| that this fix is only for d43b parts, and is skipped if the
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| version number is not $40.
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.global real_inex
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.global inex
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inex:
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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cmpib #VER_40,(%sp) |test version number
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bnes not_fmt40
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fmovel %fpsr,-(%sp)
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btstb #E1,E_BYTE(%a6) |test for E1 set
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beqs not_b1232
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btstb #snan_bit,2(%sp) |test for snan
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beq inex_ckofl
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addl #4,%sp
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frestore (%sp)+
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unlk %a6
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bra snan
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inex_ckofl:
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btstb #ovfl_bit,2(%sp) |test for ovfl
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beq inex_ckufl
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addl #4,%sp
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frestore (%sp)+
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unlk %a6
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bra ovfl
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inex_ckufl:
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btstb #unfl_bit,2(%sp) |test for unfl
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beq not_b1232
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addl #4,%sp
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frestore (%sp)+
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unlk %a6
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bra unfl
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| We do not have the bug 1232 case. Clean up the stack and call
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| real_inex.
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not_b1232:
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addl #4,%sp
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frestore (%sp)+
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unlk %a6
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real_inex:
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addl #1,siginex |for standalone testing
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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not_fmt40:
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bclrb #E3,E_BYTE(%a6) |clear and test E3 flag
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beqs inex_cke1
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| Clear dirty bit on dest resister in the frame before branching
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| to b1238_fix.
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moveml %d0/%d1,USER_DA(%a6)
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bfextu CMDREG1B(%a6){#6:#3},%d0 |get dest reg no
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bclrb %d0,FPR_DIRTY_BITS(%a6) |clr dest dirty bit
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bsrl b1238_fix |test for bug1238 case
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moveml USER_DA(%a6),%d0/%d1
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bras inex_done
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inex_cke1:
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bclrb #E1,E_BYTE(%a6)
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inex_done:
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frestore (%sp)+
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unlk %a6
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| signifies that the stack frame
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| is NOT for syscall
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movel %sp,%sp@- | stack frame pointer argument
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| Overflow exception
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|xref fpsp_ovfl
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.global real_ovfl
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.global ovfl
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ovfl:
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jmp fpsp_ovfl
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real_ovfl:
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addl #1,sigovfl |for standalone testing
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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bclrb #E3,E_BYTE(%a6) |clear and test E3 flag
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bnes ovfl_done
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bclrb #E1,E_BYTE(%a6)
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ovfl_done:
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frestore (%sp)+
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unlk %a6
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| signifies that the stack frame
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| is NOT for syscall
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movel %sp,%sp@- | stack frame pointer argument
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| Underflow exception
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|xref fpsp_unfl
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.global real_unfl
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.global unfl
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unfl:
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jmp fpsp_unfl
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real_unfl:
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addl #1,sigunfl |for standalone testing
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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bclrb #E3,E_BYTE(%a6) |clear and test E3 flag
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bnes unfl_done
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bclrb #E1,E_BYTE(%a6)
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unfl_done:
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frestore (%sp)+
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unlk %a6
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| signifies that the stack frame
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| 252 |
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| is NOT for syscall
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movel %sp,%sp@- | stack frame pointer argument
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| Signalling NAN exception
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|xref fpsp_snan
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.global real_snan
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.global snan
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snan:
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jmp fpsp_snan
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real_snan:
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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bclrb #E1,E_BYTE(%a6) |snan is always an E1 exception
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frestore (%sp)+
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unlk %a6
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addl #1,sigsnan |for standalone testing
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| 278 |
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| signifies that the stack frame
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| 279 |
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| is NOT for syscall
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| 280 |
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movel %sp,%sp@- | stack frame pointer argument
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| 281 |
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| Operand Error exception
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|xref fpsp_operr
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.global real_operr
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.global operr
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operr:
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jmp fpsp_operr
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real_operr:
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link %a6,#-LOCAL_SIZE
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fsave -(%sp)
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bclrb #E1,E_BYTE(%a6) |operr is always an E1 exception
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frestore (%sp)+
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unlk %a6
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addl #1,sigoperr |for standalone testing
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| 306 |
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| signifies that the stack frame
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| 307 |
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| is NOT for syscall
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| 308 |
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movel %sp,%sp@- | stack frame pointer argument
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| 309 |
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bsrl SYMBOL_NAME(trap_c)
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addql #4,%sp
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bral SYMBOL_NAME(ret_from_exception)
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| 314 |
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| BSUN exception
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| 316 |
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| 317 |
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| This sample handler simply clears the nan bit in the FPSR.
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|xref fpsp_bsun
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.global real_bsun
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.global bsun
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bsun:
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jmp fpsp_bsun
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real_bsun:
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| 325 |
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link %a6,#-LOCAL_SIZE
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| 326 |
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fsave -(%sp)
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| 327 |
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bclrb #E1,E_BYTE(%a6) |bsun is always an E1 exception
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| 328 |
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fmovel %FPSR,-(%sp)
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| 329 |
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bclrb #nan_bit,(%sp)
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| 330 |
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fmovel (%sp)+,%FPSR
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| 331 |
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frestore (%sp)+
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| 332 |
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unlk %a6
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| 333 |
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| 334 |
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addl #1,sigbsun |for standalone testing
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| 335 |
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| 336 |
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| 337 |
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| 338 |
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SAVE_ALL
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| 339 |
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moveq #-1,%d0
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| 340 |
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movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
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| 341 |
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| signifies that the stack frame
|
| 342 |
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| is NOT for syscall
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| 343 |
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movel %sp,%sp@- | stack frame pointer argument
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| 344 |
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bsrl SYMBOL_NAME(trap_c)
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| 345 |
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addql #4,%sp
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| 346 |
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bral SYMBOL_NAME(ret_from_exception)
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| 347 |
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| 348 |
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|
|
| 349 |
|
|
| F-line exception
|
| 350 |
|
|
|
|
| 351 |
|
|
| A 'real' F-line exception is one that the FPSP isn't supposed to
|
| 352 |
|
|
| handle. E.g. an instruction with a co-processor ID that is not 1.
|
| 353 |
|
|
|
|
| 354 |
|
|
|
|
| 355 |
|
|
|xref fpsp_fline
|
| 356 |
|
|
.global real_fline
|
| 357 |
|
|
.global fline
|
| 358 |
|
|
fline:
|
| 359 |
|
|
jmp fpsp_fline
|
| 360 |
|
|
real_fline:
|
| 361 |
|
|
|
| 362 |
|
|
addl #1,sigunimp |for standalone testing
|
| 363 |
|
|
|
| 364 |
|
|
|
| 365 |
|
|
SAVE_ALL
|
| 366 |
|
|
moveq #-1,%d0
|
| 367 |
|
|
movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
|
| 368 |
|
|
| signifies that the stack frame
|
| 369 |
|
|
| is NOT for syscall
|
| 370 |
|
|
movel %sp,%sp@- | stack frame pointer argument
|
| 371 |
|
|
bsrl SYMBOL_NAME(trap_c)
|
| 372 |
|
|
addql #4,%sp
|
| 373 |
|
|
bral SYMBOL_NAME(ret_from_exception)
|
| 374 |
|
|
|
| 375 |
|
|
|
|
| 376 |
|
|
| Unsupported data type exception
|
| 377 |
|
|
|
|
| 378 |
|
|
|xref fpsp_unsupp
|
| 379 |
|
|
.global real_unsupp
|
| 380 |
|
|
.global unsupp
|
| 381 |
|
|
unsupp:
|
| 382 |
|
|
jmp fpsp_unsupp
|
| 383 |
|
|
real_unsupp:
|
| 384 |
|
|
link %a6,#-LOCAL_SIZE
|
| 385 |
|
|
fsave -(%sp)
|
| 386 |
|
|
bclrb #E1,E_BYTE(%a6) |unsupp is always an E1 exception
|
| 387 |
|
|
frestore (%sp)+
|
| 388 |
|
|
unlk %a6
|
| 389 |
|
|
|
| 390 |
|
|
addl #1,sigunsupp |for standalone testing
|
| 391 |
|
|
|
| 392 |
|
|
|
| 393 |
|
|
SAVE_ALL
|
| 394 |
|
|
moveq #-1,%d0
|
| 395 |
|
|
movel %d0,%sp@(LOFF_ORIG_D0) | a -1 in the ORIG_D0 field
|
| 396 |
|
|
| signifies that the stack frame
|
| 397 |
|
|
| is NOT for syscall
|
| 398 |
|
|
movel %sp,%sp@- | stack frame pointer argument
|
| 399 |
|
|
bsrl SYMBOL_NAME(trap_c)
|
| 400 |
|
|
addql #4,%sp
|
| 401 |
|
|
bral SYMBOL_NAME(ret_from_exception)
|
| 402 |
|
|
|
| 403 |
|
|
|
|
| 404 |
|
|
| Trace exception
|
| 405 |
|
|
|
|
| 406 |
|
|
.global real_trace
|
| 407 |
|
|
real_trace:
|
| 408 |
|
|
|
|
| 409 |
|
|
bral SYMBOL_NAME(trap)
|
| 410 |
|
|
|
| 411 |
|
|
|
|
| 412 |
|
|
| fpsp_fmt_error --- exit point for frame format error
|
| 413 |
|
|
|
|
| 414 |
|
|
| The fpu stack frame does not match the frames existing
|
| 415 |
|
|
| or planned at the time of this writing. The fpsp is
|
| 416 |
|
|
| unable to handle frame sizes not in the following
|
| 417 |
|
|
| version:size pairs:
|
| 418 |
|
|
|
|
| 419 |
|
|
| {4060, 4160} - busy frame
|
| 420 |
|
|
| {4028, 4130} - unimp frame
|
| 421 |
|
|
| {4000, 4100} - idle frame
|
| 422 |
|
|
|
|
| 423 |
|
|
| This entry point simply holds an f-line illegal value.
|
| 424 |
|
|
| Replace this with a call to your kernel panic code or
|
| 425 |
|
|
| code to handle future revisions of the fpu.
|
| 426 |
|
|
|
|
| 427 |
|
|
.global fpsp_fmt_error
|
| 428 |
|
|
fpsp_fmt_error:
|
| 429 |
|
|
|
| 430 |
|
|
.long 0xf27f0000 |f-line illegal
|
| 431 |
|
|
|
| 432 |
|
|
|
|
| 433 |
|
|
| fpsp_done --- FPSP exit point
|
| 434 |
|
|
|
|
| 435 |
|
|
| The exception has been handled by the package and we are ready
|
| 436 |
|
|
| to return to user mode, but there may be OS specific code
|
| 437 |
|
|
| to execute before we do. If there is, do it now.
|
| 438 |
|
|
|
|
| 439 |
|
|
|
|
| 440 |
|
|
|
| 441 |
|
|
.global fpsp_done
|
| 442 |
|
|
fpsp_done:
|
| 443 |
|
|
btst #0x5,%sp@ | supervisor bit set in saved SR?
|
| 444 |
|
|
beq Lnotkern
|
| 445 |
|
|
rte
|
| 446 |
|
|
Lnotkern:
|
| 447 |
|
|
tstl SYMBOL_NAME(need_resched)
|
| 448 |
|
|
bne Lmustsched
|
| 449 |
|
|
rte
|
| 450 |
|
|
Lmustsched:
|
| 451 |
|
|
SAVE_ALL
|
| 452 |
|
|
moveq #-1,%d0
|
| 453 |
|
|
movel %d0,%sp@(LOFF_ORIG_D0) | indicate stack frame not for syscall
|
| 454 |
|
|
bral SYMBOL_NAME(ret_from_exception) | deliver signals, reschedule etc..
|
| 455 |
|
|
|
| 456 |
|
|
|
| 457 |
|
|
|
|
| 458 |
|
|
| mem_write --- write to user or supervisor address space
|
| 459 |
|
|
|
|
| 460 |
|
|
| Writes to memory while in supervisor mode. copyout accomplishes
|
| 461 |
|
|
| this via a 'moves' instruction. copyout is a UNIX SVR3 (and later) function.
|
| 462 |
|
|
| If you don't have copyout, use the local copy of the function below.
|
| 463 |
|
|
|
|
| 464 |
|
|
| a0 - supervisor source address
|
| 465 |
|
|
| a1 - user destination address
|
| 466 |
|
|
| d0 - number of bytes to write (maximum count is 12)
|
| 467 |
|
|
|
|
| 468 |
|
|
| The supervisor source address is guaranteed to point into the supervisor
|
| 469 |
|
|
| stack. The result is that a UNIX
|
| 470 |
|
|
| process is allowed to sleep as a consequence of a page fault during
|
| 471 |
|
|
| copyout. The probability of a page fault is exceedingly small because
|
| 472 |
|
|
| the 68040 always reads the destination address and thus the page
|
| 473 |
|
|
| faults should have already been handled.
|
| 474 |
|
|
|
|
| 475 |
|
|
| If the EXC_SR shows that the exception was from supervisor space,
|
| 476 |
|
|
| then just do a dumb (and slow) memory move. In a UNIX environment
|
| 477 |
|
|
| there shouldn't be any supervisor mode floating point exceptions.
|
| 478 |
|
|
|
|
| 479 |
|
|
.global mem_write
|
| 480 |
|
|
mem_write:
|
| 481 |
|
|
btstb #5,EXC_SR(%a6) |check for supervisor state
|
| 482 |
|
|
beqs user_write
|
| 483 |
|
|
super_write:
|
| 484 |
|
|
moveb (%a0)+,(%a1)+
|
| 485 |
|
|
subql #1,%d0
|
| 486 |
|
|
bnes super_write
|
| 487 |
|
|
rts
|
| 488 |
|
|
user_write:
|
| 489 |
|
|
movel %d1,-(%sp) |preserve d1 just in case
|
| 490 |
|
|
movel %d0,-(%sp)
|
| 491 |
|
|
movel %a1,-(%sp)
|
| 492 |
|
|
movel %a0,-(%sp)
|
| 493 |
|
|
jsr copyout
|
| 494 |
|
|
addw #12,%sp
|
| 495 |
|
|
movel (%sp)+,%d1
|
| 496 |
|
|
rts
|
| 497 |
|
|
|
|
| 498 |
|
|
| mem_read --- read from user or supervisor address space
|
| 499 |
|
|
|
|
| 500 |
|
|
| Reads from memory while in supervisor mode. copyin accomplishes
|
| 501 |
|
|
| this via a 'moves' instruction. copyin is a UNIX SVR3 (and later) function.
|
| 502 |
|
|
| If you don't have copyin, use the local copy of the function below.
|
| 503 |
|
|
|
|
| 504 |
|
|
| The FPSP calls mem_read to read the original F-line instruction in order
|
| 505 |
|
|
| to extract the data register number when the 'Dn' addressing mode is
|
| 506 |
|
|
| used.
|
| 507 |
|
|
|
|
| 508 |
|
|
|Input:
|
| 509 |
|
|
| a0 - user source address
|
| 510 |
|
|
| a1 - supervisor destination address
|
| 511 |
|
|
| d0 - number of bytes to read (maximum count is 12)
|
| 512 |
|
|
|
|
| 513 |
|
|
| Like mem_write, mem_read always reads with a supervisor
|
| 514 |
|
|
| destination address on the supervisor stack. Also like mem_write,
|
| 515 |
|
|
| the EXC_SR is checked and a simple memory copy is done if reading
|
| 516 |
|
|
| from supervisor space is indicated.
|
| 517 |
|
|
|
|
| 518 |
|
|
.global mem_read
|
| 519 |
|
|
mem_read:
|
| 520 |
|
|
btstb #5,EXC_SR(%a6) |check for supervisor state
|
| 521 |
|
|
beqs user_read
|
| 522 |
|
|
super_read:
|
| 523 |
|
|
moveb (%a0)+,(%a1)+
|
| 524 |
|
|
subql #1,%d0
|
| 525 |
|
|
bnes super_read
|
| 526 |
|
|
rts
|
| 527 |
|
|
user_read:
|
| 528 |
|
|
movel %d1,-(%sp) |preserve d1 just in case
|
| 529 |
|
|
movel %d0,-(%sp)
|
| 530 |
|
|
movel %a1,-(%sp)
|
| 531 |
|
|
movel %a0,-(%sp)
|
| 532 |
|
|
jsr copyin
|
| 533 |
|
|
addw #12,%sp
|
| 534 |
|
|
movel (%sp)+,%d1
|
| 535 |
|
|
rts
|
| 536 |
|
|
|
| 537 |
|
|
|
|
| 538 |
|
|
| Use these routines if your kernel doesn't have copyout/copyin equivalents.
|
| 539 |
|
|
| Assumes that D0/D1/A0/A1 are scratch registers. copyout overwrites DFC,
|
| 540 |
|
|
| and copyin overwrites SFC.
|
| 541 |
|
|
|
|
| 542 |
|
|
copyout:
|
| 543 |
|
|
movel 4(%sp),%a0 | source
|
| 544 |
|
|
movel 8(%sp),%a1 | destination
|
| 545 |
|
|
movel 12(%sp),%d0 | count
|
| 546 |
|
|
subl #1,%d0 | dec count by 1 for dbra
|
| 547 |
|
|
movel #1,%d1
|
| 548 |
|
|
movec %d1,%DFC | set dfc for user data space
|
| 549 |
|
|
moreout:
|
| 550 |
|
|
moveb (%a0)+,%d1 | fetch supervisor byte
|
| 551 |
|
|
movesb %d1,(%a1)+ | write user byte
|
| 552 |
|
|
dbf %d0,moreout
|
| 553 |
|
|
rts
|
| 554 |
|
|
|
| 555 |
|
|
copyin:
|
| 556 |
|
|
movel 4(%sp),%a0 | source
|
| 557 |
|
|
movel 8(%sp),%a1 | destination
|
| 558 |
|
|
movel 12(%sp),%d0 | count
|
| 559 |
|
|
subl #1,%d0 | dec count by 1 for dbra
|
| 560 |
|
|
movel #1,%d1
|
| 561 |
|
|
movec %d1,%SFC | set sfc for user space
|
| 562 |
|
|
morein:
|
| 563 |
|
|
movesb (%a0)+,%d1 | fetch user byte
|
| 564 |
|
|
moveb %d1,(%a1)+ | write supervisor byte
|
| 565 |
|
|
dbf %d0,morein
|
| 566 |
|
|
rts
|
| 567 |
|
|
|
| 568 |
|
|
|end
|
