freebsd-dev/sys/amd64/include/asmacros.h
John Polstra 9081eec1fb Make the necessary changes so that an ELF kernel can be built. I
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.
1997-04-22 06:55:47 +00:00

142 lines
6.1 KiB
C

/*-
* Copyright (c) 1993 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: asmacros.h,v 1.15 1997/03/09 13:57:33 bde Exp $
*/
#ifndef _MACHINE_ASMACROS_H_
#define _MACHINE_ASMACROS_H_
#include <sys/cdefs.h>
#include <machine/asnames.h>
/* XXX too much duplication in various asm*.h's. */
/*
* CNAME and HIDENAME manage the relationship between symbol names in C
* and the equivalent assembly language names. CNAME is given a name as
* it would be used in a C program. It expands to the equivalent assembly
* language name. HIDENAME is given an assembly-language name, and expands
* to a possibly-modified form that will be invisible to C programs.
*/
#if defined(__ELF__)
#define CNAME(csym) csym
#define HIDENAME(asmsym) __CONCAT(.,asmsym)
#else
#define CNAME(csym) __CONCAT(_,csym)
#define HIDENAME(asmsym) asmsym
#endif
#define ALIGN_DATA .p2align 2 /* 4 byte alignment, zero filled */
#ifdef GPROF
#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
#else
#define ALIGN_TEXT .p2align 2,0x90 /* 4-byte alignment, nop filled */
#endif
#define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
#define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
CNAME(name):
#define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
#define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
#ifdef GPROF
/*
* __mcount is like mcount except that doesn't require its caller to set
* up a frame pointer. It must be called before pushing anything onto the
* stack. gcc should eventually generate code to call __mcount in most
* cases. This would make -pg in combination with -fomit-frame-pointer
* useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
* allow profiling before setting up the frame pointer, but this is
* inadequate for good handling of special cases, e.g., -fpic works best
* with profiling after the prologue.
*
* mexitcount is a new function to support non-statistical profiling if an
* accurate clock is available. For C sources, calls to it are generated
* by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
* call mexitcount at the end of a function like the MEXITCOUNT macro does,
* but gcc currently generates calls to it at the start of the epilogue to
* avoid problems with -fpic.
*
* mcount and __mexitcount may clobber the call-used registers and %ef.
* mexitcount may clobber %ecx and %ef.
*
* Cross-jumping makes non-statistical profiling timing more complicated.
* It is handled in many cases by calling mexitcount before jumping. It is
* handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
* It is handled for some fault-handling jumps by not sharing the exit
* routine.
*
* ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
* the main entry point. Note that alt entries are counted twice. They
* have to be counted as ordinary entries for gprof to get the call times
* right for the ordinary entries.
*
* High local labels are used in macros to avoid clashes with local labels
* in functions.
*
* Ordinary `ret' is used instead of a macro `RET' because there are a lot
* of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
* be used because this file is sometimes preprocessed in traditional mode).
* `ret' clobbers eflags but this doesn't matter.
*/
#define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
#define CROSSJUMP(jtrue, label, jfalse) \
jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
#define CROSSJUMPTARGET(label) \
ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
#define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
#define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; popl %ecx
#define MCOUNT call __mcount
#define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
#define MEXITCOUNT call mexitcount
#define ret MEXITCOUNT ; NON_GPROF_RET
#else /* !GPROF */
/*
* ALTENTRY() has to align because it is before a corresponding ENTRY().
* ENTRY() has to align to because there may be no ALTENTRY() before it.
* If there is a previous ALTENTRY() then the alignment code for ENTRY()
* is empty.
*/
#define ALTENTRY(name) GEN_ENTRY(name)
#define CROSSJUMP(jtrue, label, jfalse) jtrue label
#define CROSSJUMPTARGET(label)
#define ENTRY(name) GEN_ENTRY(name)
#define FAKE_MCOUNT(caller)
#define MCOUNT
#define MCOUNT_LABEL(name)
#define MEXITCOUNT
#endif /* GPROF */
#endif /* !_MACHINE_ASMACROS_H_ */