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authorEric Andersen <andersen@codepoet.org>2001-06-15 19:58:36 +0000
committerEric Andersen <andersen@codepoet.org>2001-06-15 19:58:36 +0000
commit1a5c8c4765bd07f9503282b9db75aa4466016660 (patch)
tree5d1bc5440d5c3cec610b6a788f8273b265bf93d2 /libc/sysdeps/linux
parente7dc0f213e99f9afcdc724780068c32a175deea6 (diff)
I am very proud of myself. I managed to write a working _start for
x86 entirely in C -- no asm required. muahahahaha! -Erik
Diffstat (limited to 'libc/sysdeps/linux')
-rw-r--r--libc/sysdeps/linux/i386/Makefile12
-rw-r--r--libc/sysdeps/linux/i386/crt0.c40
2 files changed, 52 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/i386/Makefile b/libc/sysdeps/linux/i386/Makefile
index f55b91355..bb7cb6e85 100644
--- a/libc/sysdeps/linux/i386/Makefile
+++ b/libc/sysdeps/linux/i386/Makefile
@@ -20,12 +20,20 @@
# other sundry sources. Files within this library are copyright by their
# respective copyright holders.
+USE_CRT0_C=true
+
TOPDIR=../../../../
include $(TOPDIR)Rules.mak
ASFLAGS=$(CFLAGS)
+ifeq ($(USE_CRT0_C),true)
+CRT0=crt0.c
+CRT0_OBJ=$(patsubst %.c,%.o, $(CRT0))
+else
CRT0=crt0.S
CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0))
+endif
+
SSRC=__longjmp.S setjmp.S vfork.S #_start.S #clone.S
ifeq ($(UNIFIED_SYSCALL),true)
@@ -47,7 +55,11 @@ ar-target: $(OBJS) $(CRT0_OBJ)
$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
cp $(CRT0_OBJ) $(TOPDIR)libc/$(CRT0_OBJ)
+ifeq ($(USE_CRT0_C),true)
+$(CRT0_OBJ): %.o : %.c
+else
$(CRT0_OBJ): %.o : %.S
+endif
$(CC) $(CFLAGS) -c $< -o $@
$(STRIPTOOL) -x -R .note -R .comment $*.o
diff --git a/libc/sysdeps/linux/i386/crt0.c b/libc/sysdeps/linux/i386/crt0.c
new file mode 100644
index 000000000..c40224ca6
--- /dev/null
+++ b/libc/sysdeps/linux/i386/crt0.c
@@ -0,0 +1,40 @@
+/*
+ * uClibc/sysdeps/linux/i386/crt0.S
+ * Pull stuff off the stack and get uClibc moving.
+ *
+ * Copyright (C) 2001 by Lineo, inc.
+ * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ * who is very pleased he managed to do this entirely in C code.
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+extern void __uClibc_main(int argc,void *argv,void *envp);
+
+void _start(unsigned int first_arg)
+{
+ unsigned int argc;
+ char **argv, **envp;
+ unsigned long *stack;
+
+ stack = (unsigned long*) &first_arg;
+ argc = *(stack - 1);
+ argv = (char **) stack;
+ envp = (char **)stack + argc + 1;
+
+ __uClibc_main(argc, argv, envp);
+}
+