fs: separate CONFIG_FS_{FAT, EXT4} from CONFIG_CMD_{FAT, EXT*}

This makes the FAT and ext4 filesystem implementations build if
CONFIG_FS_{FAT,EXT4} are defined, rather than basing the build on
whether CONFIG_CMD_{FAT,EXT*} are defined. This will allow the
filesystems to be built separately from the filesystem-specific commands
that use them. This paves the way for the creation of filesystem-generic
commands that used the filesystems, without requiring the filesystem-
specific commands.

Minor documentation changes are made for this change.

The new config options are automatically selected by the old config
options to retain backwards-compatibility.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>

README

@@ -807,9 +807,11 @@ The following options need to be configured:
 		CONFIG_CMD_EEPROM	* EEPROM read/write support
 		CONFIG_CMD_ELF		* bootelf, bootvx
 		CONFIG_CMD_EXPORTENV	* export the environment
+		CONFIG_CMD_EXT2		* ext2 command support
+		CONFIG_CMD_EXT4		* ext4 command support
 		CONFIG_CMD_SAVEENV	  saveenv
 		CONFIG_CMD_FDC		* Floppy Disk Support
-		CONFIG_CMD_FAT		* FAT partition support
+		CONFIG_CMD_FAT		* FAT command support
 		CONFIG_CMD_FDOS		* Dos diskette Support
 		CONFIG_CMD_FLASH	  flinfo, erase, protect
 		CONFIG_CMD_FPGA		  FPGA device initialization support

doc/README.ext4

@@ -1,15 +1,28 @@
 This patch series adds support for ext4 ls,load and write features in uboot
 Journaling is supported for write feature.
 
+To enable support for the ext4 (and ext2) filesystem implementation,
+#define CONFIG_FS_EXT4
+
+If you want write support,
+#define CONFIG_EXT4_WRITE
+
 To Enable ext2 ls and load commands, modify the board specific config file with
 #define CONFIG_CMD_EXT2
+This automatically defines CONFIG_FS_EXT4 for you.
 
 To Enable ext4 ls and load commands, modify the board specific config file with
 #define CONFIG_CMD_EXT4
+This automatically defines CONFIG_FS_EXT4 for you.
 
 To enable ext4 write command, modify the board specific config file with
 #define CONFIG_CMD_EXT4
 #define CONFIG_CMD_EXT4_WRITE
+These automatically define CONFIG_FS_EXT4 and CONFIG_EXT4_WRITE for you.
+
+Also relevant are the generic filesystem commands,
+#define CONFIG_CMD_FS_GENERIC
+This does not automatically enable EXT4 support for you.
 
 Steps to test:
 

fs/ext4/Makefile

@@ -30,11 +30,8 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)libext4fs.o
 
 AOBJS	=
-COBJS-$(CONFIG_CMD_EXT4) := ext4fs.o ext4_common.o dev.o
-ifndef CONFIG_CMD_EXT4
-COBJS-$(CONFIG_CMD_EXT2) := ext4fs.o ext4_common.o dev.o
-endif
-COBJS-$(CONFIG_CMD_EXT4_WRITE) += ext4_journal.o crc16.o
+COBJS-$(CONFIG_FS_EXT4) := ext4fs.o ext4_common.o dev.o
+COBJS-$(CONFIG_EXT4_WRITE) += ext4_journal.o crc16.o
 
 SRCS	:= $(AOBJS:.o=.S) $(COBJS-y:.o=.c)
 OBJS	:= $(addprefix $(obj),$(AOBJS) $(COBJS-y))

fs/ext4/ext4_common.c

@@ -56,7 +56,7 @@ int ext4fs_indir3_blkno = -1;
 struct ext2_inode *g_parent_inode;
 static int symlinknest;
 
-#if defined(CONFIG_CMD_EXT4_WRITE)
+#if defined(CONFIG_EXT4_WRITE)
 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
 {
 	uint32_t res = size / n;

fs/ext4/ext4_common.h

@@ -37,7 +37,7 @@
 #include <ext4fs.h>
 #include <malloc.h>
 #include <asm/errno.h>
-#if defined(CONFIG_CMD_EXT4_WRITE)
+#if defined(CONFIG_EXT4_WRITE)
 #include "ext4_journal.h"
 #include "crc16.h"
 #endif
@@ -71,7 +71,7 @@ int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
 			struct ext2fs_node **fnode, int *ftype);
 
-#if defined(CONFIG_CMD_EXT4_WRITE)
+#if defined(CONFIG_EXT4_WRITE)
 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n);
 int ext4fs_checksum_update(unsigned int i);
 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags);

fs/ext4/ext4fs.c

@@ -196,7 +196,7 @@ int ext4fs_read(char *buf, unsigned len)
 	return ext4fs_read_file(ext4fs_file, 0, len, buf);
 }
 
-#if defined(CONFIG_CMD_EXT4_WRITE)
+#if defined(CONFIG_EXT4_WRITE)
 static void ext4fs_update(void)
 {
 	short i;

fs/fat/Makefile

@@ -24,11 +24,11 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)libfat.o
 
 AOBJS	=
-COBJS-$(CONFIG_CMD_FAT)	:= fat.o
+COBJS-$(CONFIG_FS_FAT)	:= fat.o
 COBJS-$(CONFIG_FAT_WRITE):= fat_write.o
 
 ifndef CONFIG_SPL_BUILD
-COBJS-$(CONFIG_CMD_FAT)	+= file.o
+COBJS-$(CONFIG_FS_FAT)	+= file.o
 endif
 
 SRCS	:= $(AOBJS:.o=.S) $(COBJS-y:.o=.c)

include/config_fallbacks.h

@@ -13,4 +13,17 @@
 #define CONFIG_SYS_BAUDRATE_TABLE	{ 9600, 19200, 38400, 57600, 115200 }
 #endif
 
+#if defined(CONFIG_CMD_FAT) && !defined(CONFIG_FS_FAT)
+#define CONFIG_FS_FAT
+#endif
+
+#if (defined(CONFIG_CMD_EXT4) || defined(CONFIG_CMD_EXT2)) && \
+						!defined(CONFIG_FS_EXT4)
+#define CONFIG_FS_EXT4
+#endif
+
+#if defined(CONFIG_CMD_EXT4_WRITE) && !defined(CONFIG_EXT4_WRITE)
+#define CONFIG_EXT4_WRITE
+#endif
+
 #endif	/* __CONFIG_FALLBACKS_H */

include/ext4fs.h

@@ -116,7 +116,7 @@ struct ext_filesystem {
 extern struct ext2_data *ext4fs_root;
 extern struct ext2fs_node *ext4fs_file;
 
-#if defined(CONFIG_CMD_EXT4_WRITE)
+#if defined(CONFIG_EXT4_WRITE)
 extern struct ext2_inode *g_parent_inode;
 extern int gd_index;
 extern int gindex;