diff options
Diffstat (limited to 'csu')
| -rw-r--r-- | csu/Makefile | 84 | ||||
| -rw-r--r-- | csu/initfini.c | 85 |
2 files changed, 169 insertions, 0 deletions
diff --git a/csu/Makefile b/csu/Makefile new file mode 100644 index 0000000000..6de77b768c --- /dev/null +++ b/csu/Makefile @@ -0,0 +1,84 @@ +# Makefile for csu code for GNU C library. + +# Copyright (C) 1995 Free Software Foundation, Inc. +# This file is part of the GNU C Library. + +# 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. + +# This directory contains the C startup code (that which calls main). This +# consists of the startfile, built from start.c and installed as crt0.o +# (traditionally) or crt1.o (for ELF); and some initialization code which +# is in the C library itself. In ELF we also install crti.o and crtn.o, +# special "initializer" and "finalizer" files in used in the link to make +# the .init and .fini sections work right; both these files are built (in +# an arcane manner) from initfini.c. + +subdir := csu + +csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o) +extra-objs = start.o $(start-installed-name) $(csu-dummies) +omit-deps = $(patsubst %.o,%,$(start-installed-name) $(csu-dummies)) +install-lib = $(start-installed-name) $(csu-dummies) +distribute = initfini.c + +all: # Make this the default target; it will be defined in Rules. + +include ../Makeconfig + +ifneq ($(elf),yes) +# When not using ELF, there is just one startfile, called crt0.o. +start-installed-name = crt0.o +else +# In the ELF universe, crt0.o is called crt1.o, and there are +# some additional bizarre files. +start-installed-name = crt1.o +install-lib += crti.o crtn.o +extra-objs += crti.o crtn.o +generated += crti.s crtn.s +omit-deps += crti crtn + +# Compile initfini.c to assembly code, which contains embedded shell +# commands that prodice crti.s-new and crtn.s-new when run. We need to +# disable emission of .size directives and debugging information, since +# they will get confused by the splitting of the output we do. +$(objpfx)cr%i.s $(objpfx)cr%n.s: initfini.c + -rm -f $(objpfx)crtcommon.tmp + (echo 'cat > crtcommon.tmp <<\EOF_common'; \ + $(CC) $< $(CPPFLAGS) $(CFLAGS) -finhibit-size-directive -g0 -S -o -; \ + echo 'EOF_common') | (cd $(@D); $(SHELL)) + cat $(objpfx)crtcommon.tmp >> $(objpfx)crti.s-new + cat $(objpfx)crtcommon.tmp >> $(objpfx)crtn.s-new + rm -f $(objpfx)crtcommon.tmp + mv -f $(objpfx)crti.s-new $(objpfx)crti.s + mv -f $(objpfx)crtn.s-new $(objpfx)crtn.s +endif + + +include ../Rules + +# The startfile is installed under different names, so we just call our +# source file `start.c' and copy to the installed name after compiling. +$(objpfx)$(start-installed-name): $(objpfx)start.o + -rm -f $@ + ln $< $@ + +# These extra files are sometimes expected by system standard linking +# procedures, but we have nothing for them to do. So compile empty files. +$(addprefix $(objpfx),$(filter-out $(start-installed-name),$(csu-dummies))): + cp /dev/null $(@:.o=.c) + $(COMPILE.c) $(@:.o=.c) $(OUTPUT_OPTION) + rm -f $(@:.o=.c) + diff --git a/csu/initfini.c b/csu/initfini.c new file mode 100644 index 0000000000..ea16e62ffe --- /dev/null +++ b/csu/initfini.c @@ -0,0 +1,85 @@ +/* Special .init and .fini section support. +Copyright (C) 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +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. */ + +/* This file is compiled into assembly code which is then surrounded by the + lines `cat > crtcommon.tmp <<\EOF_common' and `EOF_common' and thus + becomes a shell script which creates three files of assembly code. + + * The first file is crti.s-new; this puts a function prologue at the + beginning of the .init and .fini sections and defines global symbols for + those addresses, so they can be called as functions. + + * The second file is crtn.s-new; this puts the corresponding function + epilogues in the .init and .fini sections. + + * The third file is crtcommon.tmp, which is whatever miscellaneous cruft + the compiler generated at the end; it should be appended to both crti.s-new + and crtn.s-new. */ + +#include <stdlib.h> + +/* These declarations make the functions go in the right sections when + we define them below. GCC syntax does not allow the attribute + specifications to be in the function definitions themselves. */ +void _init (void) __attribute__ ((section (".init"))); +void _fini (void) __attribute__ ((section (".fini"))); + +/* End the here document containing the initial common code. + Then move the output file crtcommon.tmp to crti.s-new and crtn.s-new. */ +asm ("\nEOF_common\n\ +mv -f crtcommon.tmp crti.s-new\n\ +cp -f crti.s-new crtn.s-new"); + +/* Append the .init prologue to crti.s-new. */ +asm ("cat >> crti.s-new <<\\EOF.crti.init"); +void +_init (void) +{ + /* End the here document containing the .init prologue code. + Then fetch the .section directive just written and append that + to crtn.s-new, followed by the function epilogue. */ + asm ("\nEOF.crti.init +\n\ + fgrep .init crti.s-new >>crtn.s-new\n\ + cat >> crtn.s-new <<\\EOF.crtn.init"); +} + +/* End the here document containing the .init epilogue code. + Then append the .fini prologue to crti.s-new. */ +asm ("\nEOF.crtn.init\ +\n\ +cat >> crti.s-new <<\\EOF.crti.fini"); + +void +_fini (void) +{ + /* End the here document containing the .fini prologue code. + Then fetch the .section directive just written and append that + to crtn.s-new, followed by the function epilogue. */ + asm ("\nEOF.crti.fini\ +\n\ + fgrep .fini crti.s-new >>crtn.s-new\n\ + cat >> crtn.s-new <<\\EOF.crtn.fini"); +} + +/* End the here document containing the .fini epilogue code. + Finally, put the remainder of the generated assembly into crtcommon.tmp. */ +asm ("\nEOF.crtn.fini\ +\n\ +cat > crtcommon.tmp <<\\EOF_common"); |