16 files changed, 25 insertions, 36 deletions
diff --git a/Kconfig b/Kconfig
index 1cf990dfce..0a445313f6 100644
--- a/Kconfig
+++ b/Kconfig
@@ -157,6 +157,19 @@ config FIT
 
 if FIT
 
+config FIT_ENABLE_SHA256_SUPPORT
+	bool "Support SHA256 checksum of FIT image contents"
+	default y
+	help
+	  Enable this to support SHA256 checksum of FIT image contents. A
+	  SHA256 checksum is a 256-bit (32-byte) hash value used to check that
+	  the image contents have not been corrupted. SHA256 is recommended
+	  for use in secure applications since (as at 2016) there is no known
+	  feasible attack that could produce a 'collision' with differing
+	  input data. Use this for the highest security. Note that only the
+	  SHA256 variant is supported: SHA512 and others are not currently
+	  supported in U-Boot.
+
 config FIT_SIGNATURE
 	bool "Enable signature verification of FIT uImages"
 	depends on DM
diff --git a/README b/README
index 350b805c38..15ef469e6c 100644
--- a/README
+++ b/README
@@ -2973,15 +2973,6 @@ FIT uImage format:
 		This define is introduced, as the legacy image format is
 		enabled per default for backward compatibility.
 
-- FIT image support:
-		CONFIG_FIT_DISABLE_SHA256
-		Supporting SHA256 hashes has quite an impact on binary size.
-		For constrained systems sha256 hash support can be disabled
-		with this option.
-
-		TODO(sjg@chromium.org): Adjust this option to be positive,
-		and move it to Kconfig
-
 - Standalone program support:
 		CONFIG_STANDALONE_LOAD_ADDR
 
diff --git a/configs/dlvision-10g_defconfig b/configs/dlvision-10g_defconfig
index c3574e1996..44f7527a9c 100644
--- a/configs/dlvision-10g_defconfig
+++ b/configs/dlvision-10g_defconfig
@@ -3,6 +3,7 @@ CONFIG_IDENT_STRING=" dlvision-10g 0.06"
 CONFIG_4xx=y
 CONFIG_TARGET_DLVISION_10G=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=5
diff --git a/configs/dlvision_defconfig b/configs/dlvision_defconfig
index f9f07ee8f1..4dd09a2af8 100644
--- a/configs/dlvision_defconfig
+++ b/configs/dlvision_defconfig
@@ -3,6 +3,7 @@ CONFIG_IDENT_STRING=" dlvision 0.02"
 CONFIG_4xx=y
 CONFIG_TARGET_DLVISION=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=5
diff --git a/configs/h2200_defconfig b/configs/h2200_defconfig
index b85ed59806..9d3698c555 100644
--- a/configs/h2200_defconfig
+++ b/configs/h2200_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_TARGET_H2200=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
diff --git a/configs/io_defconfig b/configs/io_defconfig
index 5dca2b121c..27edc5976b 100644
--- a/configs/io_defconfig
+++ b/configs/io_defconfig
@@ -3,6 +3,7 @@ CONFIG_IDENT_STRING=" io 0.06"
 CONFIG_4xx=y
 CONFIG_TARGET_IO=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=5
diff --git a/configs/iocon_defconfig b/configs/iocon_defconfig
index c74df944a6..2529181620 100644
--- a/configs/iocon_defconfig
+++ b/configs/iocon_defconfig
@@ -3,6 +3,7 @@ CONFIG_IDENT_STRING=" iocon 0.06"
 CONFIG_4xx=y
 CONFIG_TARGET_IOCON=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=5
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
diff --git a/configs/neo_defconfig b/configs/neo_defconfig
index fbb2da47f0..1bf5151baa 100644
--- a/configs/neo_defconfig
+++ b/configs/neo_defconfig
@@ -3,6 +3,7 @@ CONFIG_IDENT_STRING=" neo 0.02"
 CONFIG_4xx=y
 CONFIG_TARGET_NEO=y
 CONFIG_FIT=y
+# CONFIG_FIT_ENABLE_SHA256_SUPPORT is not set
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=5
diff --git a/include/configs/dlvision-10g.h b/include/configs/dlvision-10g.h
index e32651f541..c5e227650e 100644
--- a/include/configs/dlvision-10g.h
+++ b/include/configs/dlvision-10g.h
@@ -31,9 +31,6 @@
 #define PLLMR0_DEFAULT PLLMR0_266_133_66
 #define PLLMR1_DEFAULT PLLMR1_266_133_66
 
-/* new uImage format support */
-#define CONFIG_FIT_DISABLE_SHA256
-
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 
 /*
diff --git a/include/configs/dlvision.h b/include/configs/dlvision.h
index 2b7d62b034..f8d390ba33 100644
--- a/include/configs/dlvision.h
+++ b/include/configs/dlvision.h
@@ -29,9 +29,6 @@
 #define PLLMR0_DEFAULT PLLMR0_266_133_66_33
 #define PLLMR1_DEFAULT PLLMR1_266_133_66_33
 
-/* new uImage format support */
-#define CONFIG_FIT_DISABLE_SHA256
-
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 
 /*
diff --git a/include/configs/h2200.h b/include/configs/h2200.h
index d8724f86a7..530a88e9e1 100644
--- a/include/configs/h2200.h
+++ b/include/configs/h2200.h
@@ -109,7 +109,6 @@
 
 #define CONFIG_SYS_BAUDRATE_TABLE	{ 9600, 38400, 115200 }
 
-#define CONFIG_FIT_DISABLE_SHA256
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_CMDLINE_TAG
 #define CONFIG_INITRD_TAG
diff --git a/include/configs/io.h b/include/configs/io.h
index 3e44a8c607..ee2b52a7ed 100644
--- a/include/configs/io.h
+++ b/include/configs/io.h
@@ -31,9 +31,6 @@
 #define PLLMR0_DEFAULT PLLMR0_266_133_66
 #define PLLMR1_DEFAULT PLLMR1_266_133_66
 
-/* new uImage format support */
-#define CONFIG_FIT_DISABLE_SHA256
-
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 
 /*
diff --git a/include/configs/iocon.h b/include/configs/iocon.h
index 9c3be78bc7..afa69942e8 100644
--- a/include/configs/iocon.h
+++ b/include/configs/iocon.h
@@ -33,9 +33,6 @@
 #define PLLMR0_DEFAULT PLLMR0_266_133_66
 #define PLLMR1_DEFAULT PLLMR1_266_133_66
 
-/* new uImage format support */
-#define CONFIG_FIT_DISABLE_SHA256
-
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 
 /*
diff --git a/include/configs/neo.h b/include/configs/neo.h
index 9115e251b1..1d8e13f035 100644
--- a/include/configs/neo.h
+++ b/include/configs/neo.h
@@ -31,9 +31,6 @@
 #define PLLMR0_DEFAULT PLLMR0_266_133_66_33
 #define PLLMR1_DEFAULT PLLMR1_266_133_66_33
 
-/* new uImage format support */
-#define CONFIG_FIT_DISABLE_SHA256
-
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 
 /*
diff --git a/include/image.h b/include/image.h
index 3f26f9bd1f..800426d51f 100644
--- a/include/image.h
+++ b/include/image.h
@@ -29,6 +29,7 @@ struct lmb;
 #define IMAGE_ENABLE_FIT	1
 #define IMAGE_ENABLE_OF_LIBFDT	1
 #define CONFIG_FIT_VERBOSE	1 /* enable fit_format_{error,warning}() */
+#define CONFIG_FIT_ENABLE_SHA256_SUPPORT
 
 #define IMAGE_ENABLE_IGNORE	0
 #define IMAGE_INDENT_STRING	""
@@ -62,9 +63,6 @@ struct lmb;
 #  ifdef CONFIG_SPL_SHA1_SUPPORT
 #   define IMAGE_ENABLE_SHA1	1
 #  endif
-#  ifdef CONFIG_SPL_SHA256_SUPPORT
-#   define IMAGE_ENABLE_SHA256	1
-#  endif
 # else
 #  define CONFIG_CRC32		/* FIT images need CRC32 support */
 #  define CONFIG_SHA1		/* and SHA1 */
@@ -72,14 +70,8 @@ struct lmb;
 #  define IMAGE_ENABLE_CRC32	1
 #  define IMAGE_ENABLE_MD5	1
 #  define IMAGE_ENABLE_SHA1	1
-#  define IMAGE_ENABLE_SHA256	1
 # endif
 
-#ifdef CONFIG_FIT_DISABLE_SHA256
-#undef CONFIG_SHA256
-#undef IMAGE_ENABLE_SHA256
-#endif
-
 #ifndef IMAGE_ENABLE_CRC32
 #define IMAGE_ENABLE_CRC32	0
 #endif
@@ -92,7 +84,11 @@ struct lmb;
 #define IMAGE_ENABLE_SHA1	0
 #endif
 
-#ifndef IMAGE_ENABLE_SHA256
+#if defined(CONFIG_FIT_ENABLE_SHA256_SUPPORT) || \
+	defined(CONFIG_SPL_SHA256_SUPPORT)
+#define CONFIG_SHA256
+#define IMAGE_ENABLE_SHA256	1
+#else
 #define IMAGE_ENABLE_SHA256	0
 #endif
 
diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt
index fa9c3fc8cb..4ed76f3d66 100644
--- a/scripts/config_whitelist.txt
+++ b/scripts/config_whitelist.txt
@@ -947,7 +947,6 @@ CONFIG_FFUART
 CONFIG_FILE
 CONFIG_FIRMWARE_OFFSET
 CONFIG_FIRMWARE_SIZE
-CONFIG_FIT_DISABLE_SHA256
 CONFIG_FIXED_PHY
 CONFIG_FIXED_PHY_ADDR
 CONFIG_FIXED_SDHCI_ALIGNED_BUFFER