Document new files for Linux i386/ELF port.

Fri Sep  8 16:32:12 1995  Ulrich Drepper  <drepper@gnu.ai.mit.edu>

        * sysdeps/unix/sysv/linux/Implies,
        sysdeps/unix/sysv/linux/Makefile, sysdeps/unix/sysv/linux/Subdirs,
        sysdeps/unix/sysv/linux/accept.S, sysdeps/unix/sysv/linux/adjtime.c,
        sysdeps/unix/sysv/linux/adjtimex.S, sysdeps/unix/sysv/linux/bind.S,
        sysdeps/unix/sysv/linux/connect.S, sysdeps/unix/sysv/linux/direct.h,
        sysdeps/unix/sysv/linux/dl-machine.h, sysdeps/unix/sysv/linux/errnos.h,
        sysdeps/unix/sysv/linux/fork.S, sysdeps/unix/sysv/linux/gethostid.c,
        sysdeps/unix/sysv/linux/gethostname.C,
        sysdeps/unix/sysv/linux/getpeername.S,
        sysdeps/unix/sysv/linux/getpgid.S, sysdeps/unix/sysv/linux/getpgrp.S,
	sysdeps/unix/sysv/linux/getsockname.S,
	sysdeps/unix/sysv/linux/getsockopt.S, sysdeps/unix/sysv/linux/gtty.S,
	sysdeps/unix/sysv/linux/listen.S, sysdeps/unix/sysv/linux/local_lim.h,
	sysdeps/unix/sysv/linux/madvise.c, sysdeps/unix/sysv/linux/msgctl.c,
	sysdeps/unix/sysv/linux/msgget.c, sysdeps/unix/sysv/linux/msgrcv.c,
	sysdeps/unix/sysv/linux/msgsnd.c, sysdeps/unix/sysv/linux/pipe.S,
	sysdeps/unix/sysv/linux/poll.c, sysdeps/unix/sysv/linux/readv.c,
	sysdeps/unix/sysv/linux/recv.S, sysdeps/unix/sysv/linux/recvfrom.S,
	sysdeps/unix/sysv/linux/recvmsg.S, sysdeps/unix/sysv/linux/semctl.c,
	sysdeps/unix/sysv/linux/semget.c, sysdeps/unix/sysv/linux/semop.c,
	sysdeps/unix/sysv/linux/send.S, sysdeps/unix/sysv/linux/sendmsg.S,
	sysdeps/unix/sysv/linux/sendto.S, sysdeps/unix/sysv/linux/setegid.c,
	sysdeps/unix/sysv/linux/seteuid.c, sysdeps/unix/sysv/linux/sethostid.c,
	sysdeps/unix/sysv/linux/setpgid.c, sysdeps/unix/sysv/linux/setpgrp.c,
	sysdeps/unix/sysv/linux/setsid.S, sysdeps/unix/sysv/linux/setsockopt.S,
	sysdeps/unix/sysv/linux/settimeofday.S,
	sysdeps/unix/sysv/linux/shmat.c, sysdeps/unix/sysv/linux/shmctl.c,
	sysdeps/unix/sysv/linux/shmdt.c, sysdeps/unix/sysv/linux/shmget.c,
	sysdeps/unix/sysv/linux/shutdown.S,
	sysdeps/unix/sysv/linux/sigaction.S, sysdeps/unix/sysv/linux/signal.S,
	sysdeps/unix/sysv/linux/sigpending.S, sysdeps/unix/sysv/linux/sigset.h,
	sysdeps/unix/sysv/linux/sockaddrcom.h,
	sysdeps/unix/sysv/linux/socketpair.S, sysdeps/unix/sysv/linux/speed.c,
	sysdeps/unix/sysv/linux/statbuf.h, sysdeps/unix/sysv/linux/stty.S,
	sysdeps/unix/sysv/linux/syscall.h, sysdeps/unix/sysv/linux/sysconf.c,
	sysdeps/unix/sysv/linux/tcdrain.c, sysdeps/unix/sysv/linux/tcflow.c,
	sysdeps/unix/sysv/linux/tcflush.c, sysdeps/unix/sysv/linux/tcgetattr.c,
	sysdeps/unix/sysv/linux/tcsetattr.c,
	sysdeps/unix/sysv/linux/termbits.h, sysdeps/unix/sysv/linux/ualarm.c,
	sysdeps/unix/sysv/linux/ulimit.c, sysdeps/unix/sysv/linux/usleep.c,
	sysdeps/unix/sysv/linux/utsnamelen.h, sysdeps/unix/sysv/linux/vfork.c,
	sysdeps/unix/sysv/linux/wait.c, sysdeps/unix/sysv/linux/wait4.S,
	sysdeps/unix/sysv/linux/waitpid.c, sysdeps/unix/sysv/linux/writev.c:
	New Linux/ELF specific, architecture independent files.

	sysdeps/unix/sysv/linux/i386/Dist,
	sysdeps/unix/sysv/linux/i386/Makefile,
	sysdeps/unix/sysv/linux/i386/brk.S,
	sysdeps/unix/sysv/linux/i386/fcntlbits.h,
	sysdeps/unix/sysv/linux/i386/fpu_control.c,
	sysdeps/unix/sysv/linux/i386/fpu_control.h,
	sysdeps/unix/sysv/linux/i386/fstat.S,
	sysdeps/unix/sysv/linux/i386/fxstat.S,
	sysdeps/unix/sysv/linux/i386/ieee_fpu.c,
	sysdeps/unix/sysv/linux/i386/init-first.S,
	sysdeps/unix/sysv/linux/i386/ipc.S,
	sysdeps/unix/sysv/linux/i386/lstat.S,
	sysdeps/unix/sysv/linux/i386/lxstat.S,
	sysdeps/unix/sysv/linux/i386/mknod.S,
	sysdeps/unix/sysv/linux/i386/mmap.S,
	sysdeps/unix/sysv/linux/i386/sbrk.S,
	sysdeps/unix/sysv/linux/i386/setfpucw.c,
	sysdeps/unix/sysv/linux/i386/signum.h,
	sysdeps/unix/sysv/linux/i386/socket.S,
	sysdeps/unix/sysv/linux/i386/stat.S,
	sysdeps/unix/sysv/linux/i386/syscall.S,
	sysdeps/unix/sysv/linux/i386/sysdep.S,
	sysdeps/unix/sysv/linux/i386/sysdep.h,
	sysdeps/unix/sysv/linux/i386/xmknod.S,
	sysdeps/unix/sysv/linux/i386/xstat.S:
	New Linux i386/ELF specific files.

	sysdeps/unix/sysv/linux/sys/ipc_buf.h,
	sysdeps/unix/sysv/linux/sys/mman.h,
	sysdeps/unix/sysv/linux/sys/msq_buf.h,
	sysdeps/unix/sysv/linux/sys/sem_buf.h,
	sysdeps/unix/sysv/linux/sys/shm_buf.h,
	sysdeps/unix/sysv/linux/sys/socketcall.h,
	sysdeps/unix/sysv/linux/sys/timex.h:
	New Linux/ELF specific, architecture independent header files.

1 files changed, 135 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
new file mode 100644
index 0000000000..7fe4d414e3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -0,0 +1,135 @@
+/* Copyright (C) 1992, 1993, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/* In the Linux/ELF world, C symbols are asm symbols.  */
+#define NO_UNDERSCORES
+
+/* There is some commonality.  */
+#include <sysdeps/unix/i386/sysdep.h>
+
+/* For Linux we can use the system call table in the header file
+	/usr/include/asm/unistd.h
+   of the kernel.  But these symbols do not follow the SYS_* syntax
+   so we have to redefine the `SYS_ify' macro here.  */
+#undef SYS_ify
+#ifdef __STDC__
+# define SYS_ify(syscall_name)	__NR_##syscall_name
+#else
+# define SYS_ify(syscall_name)	__NR_/**/syscall_name
+#endif
+
+
+#ifdef ASSEMBLER
+
+/* Linux uses a negative return value to indicate syscall errors, unlike
+   most Unices, which use the condition codes' carry flag.  */
+#undef	PSEUDO
+#define	PSEUDO(name, syscall_name, args)				      \
+  .text;								      \
+  .globl syscall_error;							      \
+  ENTRY (name)								      \
+    movl $SYS_ify (syscall_name), %eax;					      \
+    DO_CALL (args);							      \
+    testl %eax, %eax;							      \
+    jl JUMPTARGET (syscall_error)
+
+/* We define our own ENTRY macro because the alignment should be 16 for ELF.  */
+#undef ENTRY
+#define ENTRY(name)							      \
+  ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (name);				      \
+  ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME (name), @function)			      \
+  .align 16;								      \
+  C_LABEL (name)
+
+/* Linux takes system call arguments in registers:
+
+	syscall number	%eax	     call-clobbered
+	arg 1		%ebx	     call-saved
+	arg 2		%ecx	     call-clobbered
+	arg 3		%edx	     call-clobbered
+	arg 4		%esi	     call-saved
+	arg 5		%edi	     call-saved
+
+   The stack layout upon entering the function is:
+
+	20(%esp)	Arg# 5
+	16(%esp)	Arg# 4
+	12(%esp)	Arg# 3
+	 8(%esp)	Arg# 2
+	 4(%esp)	Arg# 1
+	  (%esp)	Return address
+
+   (Of course a function with say 3 arguments does not have entries for
+   arguments 4 and 5.)
+
+   The following code tries hard to be optimal.  A general assuption
+   (which is true accoriding to the data books I have) is that
+
+	2 * xchg	is more expensive than	pushl + movl + popl
+
+   Beside this a neat trick is used.  The calling conventions for Linux
+   tell that among the registers used for parameters %ecx and %edx need
+   not be saved.  Beside this we may clobber this registers even when
+   they are not used for parameter passing.
+
+   As a result one can see below that we save the content of the %ebx
+   register in the %edx register when we have less than 3 arguments
+   (2 * movl is less expensive than pushl + popl).
+
+   Second unlike for the other registers we don't save the content of
+   %ecx and %edx when we have than 1 and 2 registers resp.  */
+
+#undef	DO_CALL
+#define DO_CALL(args)					      		      \
+    DOARGS_##args							      \
+    int $0x80;								      \
+    UNDOARGS_##args
+
+#define	DOARGS_0	/* No arguments to frob.  */
+#define	UNDOARGS_0	/* No arguments to unfrob.  */
+#define	_DOARGS_0(n)	/* No arguments to frob.  */
+#define	_UNDOARGS_0	/* No arguments to unfrob.  */
+
+#define	DOARGS_1	movl %ebx, %edx; movl 4(%esp), %ebx; DOARGS_0
+#define	UNDOARGS_1	UNDOARGS_0; movl %edx, %ebx
+#define	_DOARGS_1(n)	pushl %ebx; movl n+4(%esp), %ebx; _DOARGS_0 (n)
+#define	_UNDOARGS_1	_UNDOARGS_0; popl %ebx
+
+#define	DOARGS_2	movl 8(%esp), %ecx; DOARGS_1
+#define	UNDOARGS_2	UNDOARGS_1
+#define	_DOARGS_2(n)	movl n(%esp), %ecx; _DOARGS_1 (n-4)
+#define	_UNDOARGS_2	_UNDOARGS_1
+
+#define DOARGS_3	_DOARGS_3 (12)
+#define UNDOARGS_3	_UNDOARGS_3
+#define _DOARGS_3(n)	movl n(%esp), %edx; _DOARGS_2 (n-4)
+#define _UNDOARGS_3	_UNDOARGS_2
+
+#define DOARGS_4	_DOARGS_4 (16)
+#define UNDOARGS_4	_UNDOARGS_4
+#define _DOARGS_4(n)	pushl %esi; movl n+4(%esp), %esi; _DOARGS_3 (n)
+#define _UNDOARGS_4	_UNDOARGS_3; popl %esi
+
+#define DOARGS_5	_DOARGS_5 (20)
+#define UNDOARGS_5	_UNDOARGS_5
+#define _DOARGS_5(n)	pushl %edi; movl n+4(%esp), %edi; _DOARGS_4 (n)
+#define _UNDOARGS_5	_UNDOARGS_4; popl %edi
+
+
+#endif	/* ASSEMBLER */