[U-Boot] [PATCH] spl: fat/fs: Add option to include/exclude FAT write build in SPL

[tien.fong.chee at intel.com]

From: Tien Fong Chee <tien.fong.chee at intel.com>

Most of the time SPL only needs very simple FAT reading, so having
CONFIG_SPL_FAT_WRITE to exclude or undefined would help to save 64KiB
default max clustersize from memory.

Signed-off-by: Tien Fong Chee <tien.fong.chee at intel.com>
---
 common/spl/Kconfig |    7 +++++++
 fs/fat/Makefile    |    7 ++++++-
 fs/fat/fat.c       |    4 +++-
 fs/fs.c            |    3 ++-
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 0ddbffc..dad4c11 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -403,6 +403,13 @@ config SPL_FAT_SUPPORT
 	  filesystem from within SPL. Support for the underlying block
 	  device (e.g. MMC or USB) must be enabled separately.
 
+config SPL_FAT_WRITE
+	bool "Support write for FAT filesystems"
+	help
+	  Enable write support for FAT and VFAT filesystems with SPL.
+	  Support for the underlying block device (e.g. MMC or USB) must be
+	  enabled separately.
+
 config SPL_FPGA_SUPPORT
 	bool "Support FPGAs"
 	help
diff --git a/fs/fat/Makefile b/fs/fat/Makefile
index e64b61a..654b8c3 100644
--- a/fs/fat/Makefile
+++ b/fs/fat/Makefile
@@ -1,5 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
 
+ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_FS_FAT)	:= fat.o
-obj-$(CONFIG_FAT_WRITE):= fat_write.o
+obj-$(CONFIG_SPL_FAT_WRITE) = fat_write.o
+else
+obj-$(CONFIG_FS_FAT)	:= fat.o
+obj-$(CONFIG_FAT_WRITE) = fat_write.o
+endif
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index ac8913e..8803fb4 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -145,7 +145,9 @@ static void get_name(dir_entry *dirent, char *s_name)
 }
 
 static int flush_dirty_fat_buffer(fsdata *mydata);
-#if !defined(CONFIG_FAT_WRITE)
+
+#if (!defined(CONFIG_SPL_BUILD) && !defined(CONFIG_FAT_WRITE)) || \
+	(defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_FAT_WRITE))
 /* Stub for read only operation */
 int flush_dirty_fat_buffer(fsdata *mydata)
 {
diff --git a/fs/fs.c b/fs/fs.c
index cb26517..0b8088b 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -168,7 +168,8 @@ static struct fstype_info fstypes[] = {
 		.exists = fat_exists,
 		.size = fat_size,
 		.read = fat_read_file,
-#ifdef CONFIG_FAT_WRITE
+#if (!defined(CONFIG_SPL_BUILD) && defined(CONFIG_FAT_WRITE)) || \
+	(defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_FAT_WRITE))
 		.write = file_fat_write,
 		.unlink = fat_unlink,
 		.mkdir = fat_mkdir,
-- 
1.7.7.4