From 6fd8c664c1bcb44429b81444be640ff08cac3702 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Tue, 13 Feb 2001 20:04:30 +0000
Subject: [PATCH] Apply a patch from Evin Robertson -- new pivot_root applet. 
 -Erik

---
 Changelog               |  6 ++++++
 Config.h                |  1 +
 applets.h               |  3 +++
 applets/usage.c         | 10 ++++++++++
 include/applets.h       |  3 +++
 pivot_root.c            | 39 +++++++++++++++++++++++++++++++++++++++
 usage.c                 | 10 ++++++++++
 util-linux/pivot_root.c | 39 +++++++++++++++++++++++++++++++++++++++
 8 files changed, 111 insertions(+)
 create mode 100644 pivot_root.c
 create mode 100644 util-linux/pivot_root.c

diff --git a/Changelog b/Changelog
index c4be93af5..45babb7ea 100644
--- a/Changelog
+++ b/Changelog
@@ -1,3 +1,9 @@
+0.50
+	* Evin Robertson -- new pivot_root applet 
+
+
+	 -Erik Andersen, not yet released
+	
 0.49
 
 	* Matt Kraai -- new sort.c
diff --git a/Config.h b/Config.h
index 65d57d20e..c9e675093 100644
--- a/Config.h
+++ b/Config.h
@@ -74,6 +74,7 @@
 //#define BB_MT
 //#define BB_NSLOOKUP
 //#define BB_PING
+//#define BB_PIVOT_ROOT
 #define BB_POWEROFF
 //#define BB_PRINTF
 #define BB_PS
diff --git a/applets.h b/applets.h
index 582b2fa38..4bd8b79e4 100644
--- a/applets.h
+++ b/applets.h
@@ -245,6 +245,9 @@ const struct BB_applet applets[] = {
 #ifdef BB_PING
 	APPLET("ping", ping_main, _BB_DIR_BIN, ping_usage)
 #endif
+#ifdef BB_PIVOT_ROOT
+	APPLET("pivot_root", pivot_root_main, _BB_DIR_SBIN, pivot_root_usage)
+#endif
 #ifdef BB_POWEROFF
 	APPLET("poweroff", poweroff_main, _BB_DIR_SBIN, poweroff_usage)
 #endif
diff --git a/applets/usage.c b/applets/usage.c
index 52c0a6915..13107c6e0 100644
--- a/applets/usage.c
+++ b/applets/usage.c
@@ -1012,6 +1012,16 @@ const char ping_usage[] =
 #endif
 #endif
 
+#if defined BB_PIVOT_ROOT
+const char pivot_root_usage[] =
+	"pivot_root new_root put_old"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+	"\n\nMove the current root file system to put_old and make new_root\n"
+	"the new root file system."
+#endif
+	;
+#endif
+
 #if defined BB_POWEROFF
 const char poweroff_usage[] =
 	"poweroff"
diff --git a/include/applets.h b/include/applets.h
index 582b2fa38..4bd8b79e4 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -245,6 +245,9 @@ const struct BB_applet applets[] = {
 #ifdef BB_PING
 	APPLET("ping", ping_main, _BB_DIR_BIN, ping_usage)
 #endif
+#ifdef BB_PIVOT_ROOT
+	APPLET("pivot_root", pivot_root_main, _BB_DIR_SBIN, pivot_root_usage)
+#endif
 #ifdef BB_POWEROFF
 	APPLET("poweroff", poweroff_main, _BB_DIR_SBIN, poweroff_usage)
 #endif
diff --git a/pivot_root.c b/pivot_root.c
new file mode 100644
index 000000000..92fe4aeab
--- /dev/null
+++ b/pivot_root.c
@@ -0,0 +1,39 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * pivot_root.c - Change root file system.  Based on util-linux 2.10s
+ *
+ * busyboxed by Evin Robertson
+ */
+#include "busybox.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <linux/unistd.h>
+
+#ifndef __NR_pivot_root
+#error Sorry, but this kernel does not support the pivot_root syscall
+#endif
+
+static _syscall2(int,pivot_root,const char *,new_root,const char *,put_old)
+
+
+int pivot_root_main(int argc, char **argv)
+{
+    if (argc != 3)
+        usage(pivot_root_usage);
+
+    if (pivot_root(argv[1],argv[2]) < 0)
+        perror_msg_and_die("pivot_root");
+
+    return EXIT_SUCCESS;
+
+}
+
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/
diff --git a/usage.c b/usage.c
index 52c0a6915..13107c6e0 100644
--- a/usage.c
+++ b/usage.c
@@ -1012,6 +1012,16 @@ const char ping_usage[] =
 #endif
 #endif
 
+#if defined BB_PIVOT_ROOT
+const char pivot_root_usage[] =
+	"pivot_root new_root put_old"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+	"\n\nMove the current root file system to put_old and make new_root\n"
+	"the new root file system."
+#endif
+	;
+#endif
+
 #if defined BB_POWEROFF
 const char poweroff_usage[] =
 	"poweroff"
diff --git a/util-linux/pivot_root.c b/util-linux/pivot_root.c
new file mode 100644
index 000000000..92fe4aeab
--- /dev/null
+++ b/util-linux/pivot_root.c
@@ -0,0 +1,39 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * pivot_root.c - Change root file system.  Based on util-linux 2.10s
+ *
+ * busyboxed by Evin Robertson
+ */
+#include "busybox.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <linux/unistd.h>
+
+#ifndef __NR_pivot_root
+#error Sorry, but this kernel does not support the pivot_root syscall
+#endif
+
+static _syscall2(int,pivot_root,const char *,new_root,const char *,put_old)
+
+
+int pivot_root_main(int argc, char **argv)
+{
+    if (argc != 3)
+        usage(pivot_root_usage);
+
+    if (pivot_root(argv[1],argv[2]) < 0)
+        perror_msg_and_die("pivot_root");
+
+    return EXIT_SUCCESS;
+
+}
+
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/