1 files changed, 121 insertions, 0 deletions
diff --git a/usr/klibc/libc_init.c b/usr/klibc/libc_init.c
new file mode 100644
index 0000000..c5b9bab
--- /dev/null
+++ b/usr/klibc/libc_init.c
@@ -0,0 +1,121 @@
+/*
+ * libc_init.c
+ *
+ * This function takes the raw data block set up by the ELF loader
+ * in the kernel and parses it.  It is invoked by crt0.S which makes
+ * any necessary adjustments and passes calls this function using
+ * the standard C calling convention.
+ *
+ * The arguments are:
+ *  uintptr_t *elfdata	 -- The ELF loader data block; usually from the stack.
+ *                          Basically a pointer to argc.
+ *  void (*onexit)(void) -- Function to install into onexit
+ */
+
+/*
+ * Several Linux ABIs don't pass the onexit pointer, and the ones that
+ * do never use it.  Therefore, unless USE_ONEXIT is defined, we just
+ * ignore the onexit pointer.
+ */
+/* #define USE_ONEXIT */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <klibc/compiler.h>
+#include <elf.h>
+#include <sys/auxv.h>
+#include <klibc/sysconfig.h>
+#include "atexit.h"
+
+#if _KLIBC_HAS_ARCHINIT
+# include "klibc/archinit.h"
+#else
+# define __libc_archinit() ((void)0)
+#endif
+
+/* This file is included from __static_init.c or __shared_init.c */
+#ifndef SHARED
+# error "SHARED should be defined to 0 or 1"
+#endif
+
+char **environ;
+unsigned int __page_size, __page_shift;
+
+struct auxentry {
+	unsigned long type;
+	unsigned long v;
+};
+
+extern void __libc_init_stdio(void);
+
+unsigned long __auxval[_AUXVAL_MAX];
+
+__noreturn __libc_init(uintptr_t * elfdata, void (*onexit) (void))
+{
+	int argc;
+	char **argv, **envp, **envend;
+	struct auxentry *auxentry;
+#if SHARED
+	typedef int (*main_t) (int, char **, char **);
+	main_t MAIN = NULL;
+#else
+	extern int main(int, char **, char **);
+#define MAIN main
+#endif
+	unsigned int page_size = 0, page_shift = 0;
+
+#ifdef USE_ONEXIT
+	if (onexit) {
+		static struct atexit at_exit;
+
+		at_exit.fctn = (void (*)(int, void *))onexit;
+		/* at_exit.next = NULL already */
+		__atexit_list = &at_exit;
+	}
+#else
+	(void)onexit;		/* Ignore this... */
+#endif
+
+	argc = (int)*elfdata++;
+	argv = (char **)elfdata;
+	envp = argv + (argc + 1);
+
+	/* The auxillary entry vector is after all the environment vars */
+	for (envend = envp; *envend; envend++) ;
+	auxentry = (struct auxentry *)(envend + 1);
+
+	while (auxentry->type) {
+		if (auxentry->type < _AUXVAL_MAX)
+			__auxval[auxentry->type] = auxentry->v;
+		auxentry++;
+	}
+
+#if SHARED
+	MAIN = (main_t) __auxval[AT_ENTRY];
+#endif
+
+	__page_size = page_size = __auxval[AT_PAGESZ];
+
+#if __GNUC__ >= 4
+	/* unsigned int is 32 bits on all our architectures */
+	page_shift = __builtin_clz(page_size) ^ 31;
+#elif defined(__i386__) || defined(__x86_64__)
+	asm("bsrl %1,%0" : "=r" (page_shift) : "r" (page_size));
+#else
+	while (page_size > 1) {
+		page_shift++;
+		page_size >>= 1;
+	}
+#endif
+	__page_shift = page_shift;
+
+#if _KLIBC_HAS_ARCHINIT
+	__libc_archinit();
+#endif
+
+	__libc_init_stdio();
+
+	environ = envp;
+	exit(MAIN(argc, argv, envp));
+}