afa8862328
a heavily stripped down FreeBSD/i386 (brutally stripped down actually) to attempt to get a stable base to start from. There is a lot missing still. Worth noting: - The kernel runs at 1GB in order to cheat with the pmap code. pmap uses a variation of the PAE code in order to avoid having to worry about 4 levels of page tables yet. - It boots in 64 bit "long mode" with a tiny trampoline embedded in the i386 loader. This simplifies locore.s greatly. - There are still quite a few fragments of i386-specific code that have not been translated yet, and some that I cheated and wrote dumb C versions of (bcopy etc). - It has both int 0x80 for syscalls (but using registers for argument passing, as is native on the amd64 ABI), and the 'syscall' instruction for syscalls. int 0x80 preserves all registers, 'syscall' does not. - I have tried to minimize looking at the NetBSD code, except in a couple of places (eg: to find which register they use to replace the trashed %rcx register in the syscall instruction). As a result, there is not a lot of similarity. I did look at NetBSD a few times while debugging to get some ideas about what I might have done wrong in my first attempt.
142 lines
6.1 KiB
C
142 lines
6.1 KiB
C
/*-
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* Copyright (c) 1993 The Regents of the University of California.
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* All rights reserved.
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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 reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _MACHINE_ASMACROS_H_
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#define _MACHINE_ASMACROS_H_
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#include <sys/cdefs.h>
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/* XXX too much duplication in various asm*.h's. */
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/*
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* CNAME and HIDENAME manage the relationship between symbol names in C
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* and the equivalent assembly language names. CNAME is given a name as
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* it would be used in a C program. It expands to the equivalent assembly
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* language name. HIDENAME is given an assembly-language name, and expands
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* to a possibly-modified form that will be invisible to C programs.
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*/
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#define CNAME(csym) csym
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#define HIDENAME(asmsym) .asmsym
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#define ALIGN_DATA .p2align 3 /* 8 byte alignment, zero filled */
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#ifdef GPROF
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#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
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#else
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#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
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#endif
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#define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
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#define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
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.type CNAME(name),@function; CNAME(name):
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#define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
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#define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
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#ifdef LOCORE
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#define PCPU(member) %gs:PC_ ## member
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#define PCPU_ADDR(member, reg) movq %gs:PC_PRVSPACE,reg; \
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addq $PC_ ## member,reg
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#endif
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#ifdef GPROF
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/*
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* __mcount is like [.]mcount except that doesn't require its caller to set
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* up a frame pointer. It must be called before pushing anything onto the
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* stack. gcc should eventually generate code to call __mcount in most
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* cases. This would make -pg in combination with -fomit-frame-pointer
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* useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
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* allow profiling before setting up the frame pointer, but this is
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* inadequate for good handling of special cases, e.g., -fpic works best
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* with profiling after the prologue.
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*
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* [.]mexitcount is a new function to support non-statistical profiling if an
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* accurate clock is available. For C sources, calls to it are generated
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* by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
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* call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
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* but gcc currently generates calls to it at the start of the epilogue to
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* avoid problems with -fpic.
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*
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* [.]mcount and __mcount may clobber the call-used registers and %ef.
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* [.]mexitcount may clobber %ecx and %ef.
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*
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* Cross-jumping makes non-statistical profiling timing more complicated.
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* It is handled in many cases by calling [.]mexitcount before jumping. It
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* is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
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* It is handled for some fault-handling jumps by not sharing the exit
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* routine.
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*
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* ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
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* the main entry point. Note that alt entries are counted twice. They
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* have to be counted as ordinary entries for gprof to get the call times
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* right for the ordinary entries.
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*
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* High local labels are used in macros to avoid clashes with local labels
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* in functions.
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*
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* Ordinary `ret' is used instead of a macro `RET' because there are a lot
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* of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
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* be used because this file is sometimes preprocessed in traditional mode).
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* `ret' clobbers eflags but this doesn't matter.
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*/
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#define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
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#define CROSSJUMP(jtrue, label, jfalse) \
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jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
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#define CROSSJUMPTARGET(label) \
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ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
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#define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
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#define FAKE_MCOUNT(caller) pushq caller ; call __mcount ; popl %ecx
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#define MCOUNT call __mcount
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#define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
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#define MEXITCOUNT call HIDENAME(mexitcount)
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#define ret MEXITCOUNT ; NON_GPROF_RET
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#else /* !GPROF */
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/*
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* ALTENTRY() has to align because it is before a corresponding ENTRY().
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* ENTRY() has to align to because there may be no ALTENTRY() before it.
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* If there is a previous ALTENTRY() then the alignment code for ENTRY()
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* is empty.
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*/
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#define ALTENTRY(name) GEN_ENTRY(name)
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#define CROSSJUMP(jtrue, label, jfalse) jtrue label
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#define CROSSJUMPTARGET(label)
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#define ENTRY(name) GEN_ENTRY(name)
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#define FAKE_MCOUNT(caller)
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#define MCOUNT
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#define MCOUNT_LABEL(name)
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#define MEXITCOUNT
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#endif /* GPROF */
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#endif /* !_MACHINE_ASMACROS_H_ */
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