sdbfs: lib: fixes so it builds for all three environments

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

sdbfs/lib/Makefile

 
+LINUX ?= /lib/modules/$(shell uname -r)/build
+
+# If we compile for the kernel, we need to include real kernel headers.
+# The thing is enough a mess that I moved it to a different file
+include Makefile.arch
+
+
 AS              = $(CROSS_COMPILE)as
 LD              = $(CROSS_COMPILE)ld
 CC              = $(CROSS_COMPILE)gcc
@@ -9,10 +16,15 @@ STRIP           = $(CROSS_COMPILE)strip
 OBJCOPY         = $(CROSS_COMPILE)objcopy
 OBJDUMP         = $(CROSS_COMPILE)objdump
 
+# calculate endianness at compile time
+ENDIAN := $(shell ./check-endian $(CC))
+
 CFLAGS = -Wall -ggdb -O2
 CFLAGS += -I../include/linux # for <sdb.h>
 CFLAGS += -ffunction-sections -fdata-sections
 CFLAGS += -Wno-pointer-sign
+CFLAGS += $(ENDIAN) $(LINUXINCLUDE)
+
 
 LIB = libsdbfs.a
 OBJS = glue.o access.o

sdbfs/lib/libsdbfs-freestanding.h

 
-#error "freestanding support for libsdbfs is not yet available"
-
 /* Though freestanding, some minimal headers are expected to exist */
 #include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 #include <errno.h>
 
 #define SDB_KERNEL	0
 #define SDB_USER	0
 #define SDB_FREESTAND	1
+
+#ifdef SDBFS_BIG_ENDIAN
+#  define ntohs(x) (x)
+#  define htons(x) (x)
+#  define ntohl(x) (x)
+#  define htonl(x) (x)
+#else
+#  error "No support, yet, for little-endian freestanding library"
+#endif

sdbfs/lib/libsdbfs-kernel.h

 
-#error "kernel support for libsdbfs is not yet available"
-
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/errno.h>
+#include <asm/byteorder.h>
+
+/*
+ * The default installed /usr/include/linux stuff misses the __KERNEL__ parts.
+ * For libsdbfs it means we won't get uint32_t and similar types.
+ *
+ * So, check if we got the information we need before strange errors happen.
+ * The DECLARE_BITMAP macro is in <linux/types.h> since the epoch, but it
+ * is not installed in /usr/include/linux/types.h, so use it to check.
+ */
+#ifndef DECLARE_BITMAP
+#  error "Please point LINUX to a source tree if you define __KERNEL__"
+#endif
 
 #define SDB_KERNEL	1
 #define SDB_USER	0

sdbfs/lib/libsdbfs.h

 #ifndef __LIBSDBFS_H__
 #define __LIBSDBFS_H__
 
-#include <sdb.h> /* Please point your "-I" to some sensible place */
-
 /* The library can work in three different environments */
 #ifdef __KERNEL__
 #  include "libsdbfs-kernel.h"
-#elif defined(__linux__)
+#elif defined(__unix__)
 #  include "libsdbfs-user.h"
 #else
 #  include "libsdbfs-freestanding.h"
 #endif
 
+#include <sdb.h> /* Please point your "-I" to some sensible place */
+
 /*
  * Data structures: please not that the library intself doesn't use
  * malloc, so it's the caller who must deal withallocation/removal.