9081eec1fb
have successfully built, booted, and run a number of different ELF kernel configurations, including GENERIC. LINT also builds and links cleanly, though I have not tried to boot it. The impact on developers is virtually nil, except for two things. All linker sets that might possibly be present in the kernel must be listed in "sys/i386/i386/setdefs.h". And all C symbols that are also referenced from assembly language code must be listed in "sys/i386/include/asnames.h". It so happens that failure to do these things will have no impact on the a.out kernel. But it will break the build of the ELF kernel. The ELF bootloader works, but it is not ready to commit quite yet.
177 lines
4.5 KiB
ArmAsm
177 lines
4.5 KiB
ArmAsm
/*
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* reg_norm.s
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*
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* Normalize the value in a FPU_REG.
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*
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* Call from C as:
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* void normalize(FPU_REG *n)
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*
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* void normalize_nuo(FPU_REG *n)
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*
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*
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* Copyright (C) 1992,1993,1994
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* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
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* Australia. E-mail billm@vaxc.cc.monash.edu.au
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* All rights reserved.
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*
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* This copyright notice covers the redistribution and use of the
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* FPU emulator developed by W. Metzenthen. It covers only its use
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* in the 386BSD, FreeBSD and NetBSD operating systems. Any other
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* use is not permitted under this copyright.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must include information specifying
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* that source code for the emulator is freely available and include
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* either:
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* a) an offer to provide the source code for a nominal distribution
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* fee, or
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* b) list at least two alternative methods whereby the source
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* can be obtained, e.g. a publically accessible bulletin board
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* and an anonymous ftp site from which the software can be
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* downloaded.
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* 3. All advertising materials specifically mentioning features or use of
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* this emulator must acknowledge that it was developed by W. Metzenthen.
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* 4. The name of W. Metzenthen may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*
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* The purpose of this copyright, based upon the Berkeley copyright, is to
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* ensure that the covered software remains freely available to everyone.
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*
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* The software (with necessary differences) is also available, but under
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* the terms of the GNU copyleft, for the Linux operating system and for
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* the djgpp ms-dos extender.
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*
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* W. Metzenthen June 1994.
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*
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*
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* $Id: reg_norm.s,v 1.6 1997/02/22 09:29:24 peter Exp $
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*
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*/
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#include <gnu/i386/fpemul/fpu_asm.h>
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.text
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ENTRY(normalize)
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pushl %ebp
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movl %esp,%ebp
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pushl %ebx
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movl PARAM1,%ebx
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movl SIGH(%ebx),%edx
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movl SIGL(%ebx),%eax
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orl %edx,%edx /* ms bits */
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js L_done /* Already normalized */
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jnz L_shift_1 /* Shift left 1 - 31 bits */
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orl %eax,%eax
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jz L_zero /* The contents are zero */
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/* L_shift_32: */
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movl %eax,%edx
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xorl %eax,%eax
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subl $32,EXP(%ebx) /* This can cause an underflow */
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/* We need to shift left by 1 - 31 bits */
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L_shift_1:
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bsrl %edx,%ecx /* get the required shift in %ecx */
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subl $31,%ecx
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negl %ecx
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shld %cl,%eax,%edx
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shl %cl,%eax
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subl %ecx,EXP(%ebx) /* This can cause an underflow */
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movl %edx,SIGH(%ebx)
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movl %eax,SIGL(%ebx)
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L_done:
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cmpl EXP_OVER,EXP(%ebx)
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jge L_overflow
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cmpl EXP_UNDER,EXP(%ebx)
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jle L_underflow
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L_exit:
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popl %ebx
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leave
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ret
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L_zero:
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movl EXP_UNDER,EXP(%ebx)
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movb TW_Zero,TAG(%ebx)
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jmp L_exit
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L_underflow:
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push %ebx
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call _arith_underflow
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pop %ebx
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jmp L_exit
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L_overflow:
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push %ebx
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call _arith_overflow
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pop %ebx
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jmp L_exit
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/* Normalise without reporting underflow or overflow */
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ENTRY(normalize_nuo)
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pushl %ebp
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movl %esp,%ebp
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pushl %ebx
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movl PARAM1,%ebx
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movl SIGH(%ebx),%edx
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movl SIGL(%ebx),%eax
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orl %edx,%edx /* ms bits */
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js L_exit /* Already normalized */
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jnz L_nuo_shift_1 /* Shift left 1 - 31 bits */
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orl %eax,%eax
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jz L_zero /* The contents are zero */
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/* L_nuo_shift_32: */
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movl %eax,%edx
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xorl %eax,%eax
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subl $32,EXP(%ebx) /* This can cause an underflow */
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/* We need to shift left by 1 - 31 bits */
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L_nuo_shift_1:
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bsrl %edx,%ecx /* get the required shift in %ecx */
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subl $31,%ecx
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negl %ecx
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shld %cl,%eax,%edx
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shl %cl,%eax
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subl %ecx,EXP(%ebx) /* This can cause an underflow */
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movl %edx,SIGH(%ebx)
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movl %eax,SIGL(%ebx)
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jmp L_exit
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