More portable handling of loop header files, as done in util-linux

Makefile

@@ -42,7 +42,7 @@ DODMALLOC = false
 
 # If you are running a cross compiler, you may want to set this
 # to something more interesting...
-CROSS =
+CROSS = #powerpc-linux-
 CC = $(CROSS)gcc
 STRIPTOOL = $(CROSS)strip
 
@@ -83,12 +83,13 @@ else
     ifeq ($(DOSTATIC),true)
 	LDFLAGS += --static
 	#
-	#use '-ffunction-sections -fdata-sections' and '--gc-sections' if they work
-	#to try and strip out any unused junk.  Doesn't do much for me, but you may
-	#want to give it a shot...
+	#use '-ffunction-sections -fdata-sections' and '--gc-sections' (if they 
+	# work) to try and strip out any unused junk.  Doesn't do much for me, 
+	# but you may want to give it a shot...
 	#
 	#ifeq ($(shell $(CC) -ffunction-sections -fdata-sections -S \
-	#	-o /dev/null -xc /dev/null 2>/dev/null && $(LD) --gc-sections -v >/dev/null && echo 1),1)
+	#	-o /dev/null -xc /dev/null 2>/dev/null && $(LD) \
+	#			--gc-sections -v >/dev/null && echo 1),1)
 	#	CFLAGS += -ffunction-sections -fdata-sections
 	#	LDFLAGS += --gc-sections
 	#endif
@@ -106,7 +107,8 @@ ifdef BB_INIT_SCRIPT
     CFLAGS += -DINIT_SCRIPT='"$(BB_INIT_SCRIPT)"'
 endif
 
-all: busybox busybox.links doc
+
+all: loop.h busybox busybox.links doc
 
 doc: olddoc
 
@@ -164,6 +166,11 @@ busybox.links: busybox.def.h
 nfsmount.o cmdedit.o: %.o: %.h
 $(OBJECTS): %.o: busybox.def.h internal.h  %.c Makefile
 
+utility.o: 
+
+loop.h:
+	@./mk_loop_h.sh
+
 test tests:
 	cd tests && $(MAKE) all
 

libbb/mk_loop_h.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+#
+# Figure out (i) the type of dev_t (ii) the defines for loop stuff
+#
+
+rm -f loop.h
+
+# Since 1.3.79 there is an include file <asm/posix_types.h>
+# that defines __kernel_dev_t.
+# (The file itself appeared in 1.3.78, but there it defined __dev_t.)
+# If it exists, we use it, or, rather, <linux/posix_types.h> which
+# avoids namespace pollution.  Otherwise we guess that __kernel_dev_t
+# is an unsigned short (which is true on i386, but false on alpha).
+
+if [ -f /usr/include/linux/posix_types.h ]; then
+   echo '#include <linux/posix_types.h>' >> loop.h
+   echo '#undef dev_t' >> loop.h
+   echo '#define dev_t __kernel_dev_t' >> loop.h
+else
+   echo '#undef dev_t' >> loop.h
+   echo '#define dev_t unsigned short' >> loop.h
+fi
+
+# Next we have to find the loop stuff itself.
+# First try kernel source, then a private version.
+
+if [ -f /usr/include/linux/loop.h ]; then
+   echo '#include <linux/loop.h>' >> loop.h
+else
+   echo '#include "real_loop.h"' >> loop.h
+fi
+
+echo '#undef dev_t' >> loop.h
+

mk_loop_h.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+#
+# Figure out (i) the type of dev_t (ii) the defines for loop stuff
+#
+
+rm -f loop.h
+
+# Since 1.3.79 there is an include file <asm/posix_types.h>
+# that defines __kernel_dev_t.
+# (The file itself appeared in 1.3.78, but there it defined __dev_t.)
+# If it exists, we use it, or, rather, <linux/posix_types.h> which
+# avoids namespace pollution.  Otherwise we guess that __kernel_dev_t
+# is an unsigned short (which is true on i386, but false on alpha).
+
+if [ -f /usr/include/linux/posix_types.h ]; then
+   echo '#include <linux/posix_types.h>' >> loop.h
+   echo '#undef dev_t' >> loop.h
+   echo '#define dev_t __kernel_dev_t' >> loop.h
+else
+   echo '#undef dev_t' >> loop.h
+   echo '#define dev_t unsigned short' >> loop.h
+fi
+
+# Next we have to find the loop stuff itself.
+# First try kernel source, then a private version.
+
+if [ -f /usr/include/linux/loop.h ]; then
+   echo '#include <linux/loop.h>' >> loop.h
+else
+   echo '#include "real_loop.h"' >> loop.h
+fi
+
+echo '#undef dev_t' >> loop.h
+

real_loop.h

@@ -0,0 +1,37 @@
+/*
+ * include/linux/loop.h
+ *
+ * Written by Theodore Ts'o, 3/29/93.
+ *
+ * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
+ * permitted under the GNU Public License.
+ */
+
+#define LO_NAME_SIZE	64
+#define LO_KEY_SIZE	32
+       
+struct loop_info {
+	int		lo_number;	/* ioctl r/o */
+	dev_t		lo_device; 	/* ioctl r/o */
+	unsigned long	lo_inode; 	/* ioctl r/o */
+	dev_t		lo_rdevice; 	/* ioctl r/o */
+	int		lo_offset;
+	int		lo_encrypt_type;
+	int		lo_encrypt_key_size; 	/* ioctl w/o */
+	int		lo_flags;	/* ioctl r/o */
+	char		lo_name[LO_NAME_SIZE];
+	unsigned char	lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+	unsigned long	lo_init[2];
+	char		reserved[4];
+};
+
+#define LO_CRYPT_NONE	0
+#define LO_CRYPT_XOR	1
+#define LO_CRYPT_DES	2
+#define LO_CRYPT_IDEA	3
+#define MAX_LO_CRYPT	4
+
+#define LOOP_SET_FD	0x4C00
+#define LOOP_CLR_FD	0x4C01
+#define LOOP_SET_STATUS	0x4C02
+#define LOOP_GET_STATUS	0x4C03

utility.c

@@ -53,11 +53,6 @@
 #include <sys/ioctl.h>
 #include <sys/utsname.h>		/* for uname(2) */
 
-#if defined BB_FEATURE_MOUNT_LOOP
-#include <fcntl.h>
-#include <linux/loop.h> /* Pull in loop device support */
-#endif
-
 /* Busybox mount uses either /proc/filesystems or /dev/mtab to get the 
  * list of available filesystems used for the -t auto option */ 
 #if defined BB_FEATURE_USE_PROCFS && defined BB_FEATURE_USE_DEVPS_PATCH
@@ -1459,7 +1454,11 @@ extern int vdprintf(int d, const char *format, va_list ap)
 }
 #endif							/* BB_SYSLOGD */
 
+
 #if defined BB_FEATURE_MOUNT_LOOP
+#include <fcntl.h>
+#include "loop.h" /* Pull in loop device support */
+
 extern int del_loop(const char *device)
 {
 	int fd;