I am very proud of myself. I managed to write a working _start for

x86 entirely in C -- no asm required.  muahahahaha!
 -Erik

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);
+}
+