image: Use the correct checks for CRC32

Add a host Kconfig for CRC32. With this we can use CONFIG_IS_ENABLED(CRC32)
directly in the host build, so drop the unnecessary indirection.

Add a few more conditions to SPL_CRC32 to avoid build failures as well as
TPL_CRC32. Also update hash.c to make crc32 optional and to actually take
notice of SPL_CRC32.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

common/hash.c

@@ -178,7 +178,7 @@ static int hash_finish_crc16_ccitt(struct hash_algo *algo, void *ctx,
 	return 0;
 }
 
-static int hash_init_crc32(struct hash_algo *algo, void **ctxp)
+static int __maybe_unused hash_init_crc32(struct hash_algo *algo, void **ctxp)
 {
 	uint32_t *ctx = malloc(sizeof(uint32_t));
 	*ctx = 0;
@@ -186,15 +186,16 @@ static int hash_init_crc32(struct hash_algo *algo, void **ctxp)
 	return 0;
 }
 
-static int hash_update_crc32(struct hash_algo *algo, void *ctx,
-			     const void *buf, unsigned int size, int is_last)
+static int __maybe_unused hash_update_crc32(struct hash_algo *algo, void *ctx,
+					    const void *buf, unsigned int size,
+					    int is_last)
 {
 	*((uint32_t *)ctx) = crc32(*((uint32_t *)ctx), buf, size);
 	return 0;
 }
 
-static int hash_finish_crc32(struct hash_algo *algo, void *ctx, void *dest_buf,
-			     int size)
+static int __maybe_unused hash_finish_crc32(struct hash_algo *algo, void *ctx,
+					    void *dest_buf, int size)
 {
 	if (size < algo->digest_size)
 		return -1;
@@ -311,6 +312,7 @@ static struct hash_algo hash_algo[] = {
 		.hash_update	= hash_update_crc16_ccitt,
 		.hash_finish	= hash_finish_crc16_ccitt,
 	},
+#if CONFIG_IS_ENABLED(CRC32)
 	{
 		.name		= "crc32",
 		.digest_size	= 4,
@@ -320,6 +322,7 @@ static struct hash_algo hash_algo[] = {
 		.hash_update	= hash_update_crc32,
 		.hash_finish	= hash_finish_crc32,
 	},
+#endif
 };
 
 /* Try to minimize code size for boards that don't want much hashing */

common/spl/Kconfig

@@ -419,7 +419,8 @@ config SYS_MMCSD_RAW_MODE_EMMC_BOOT_PARTITION
 
 config SPL_CRC32
 	bool "Support CRC32"
-	default y if SPL_LEGACY_IMAGE_SUPPORT
+	default y if SPL_LEGACY_IMAGE_SUPPORT || SPL_EFI_PARTITION
+	default y if SPL_ENV_SUPPORT || TPL_BLOBLIST
 	help
 	  Enable this to support CRC32 in uImages or FIT images within SPL.
 	  This is a 32-bit checksum value that can be used to verify images.
@@ -1419,6 +1420,16 @@ config TPL_BOOTROM_SUPPORT
 	  BOOT_DEVICE_BOOTROM (or fall-through to the next boot device in the
 	  boot device list, if not implemented for a given board)
 
+config TPL_CRC32
+	bool "Support CRC32 in TPL"
+	default y if TPL_ENV_SUPPORT || TPL_BLOBLIST
+	help
+	  Enable this to support CRC32 in uImages or FIT images within SPL.
+	  This is a 32-bit checksum value that can be used to verify images.
+	  For FIT images, this is the least secure type of checksum, suitable
+	  for detected accidental image corruption. For secure applications you
+	  should consider SHA1 or SHA256.
+
 config TPL_DRIVERS_MISC
 	bool "Support misc drivers in TPL"
 	help

lib/Kconfig

@@ -496,6 +496,11 @@ config SPL_MD5
 	  security applications, but it can be useful for providing a quick
 	  checksum of a block of data.
 
+config CRC32
+	def_bool y
+	help
+	  Enables CRC32 support in U-Boot. This is normally required.
+
 config CRC32C
 	bool
 

lib/Makefile

@@ -96,9 +96,7 @@ obj-y += display_options.o
 CFLAGS_display_options.o := $(if $(BUILD_TAG),-DBUILD_TAG='"$(BUILD_TAG)"')
 obj-$(CONFIG_BCH) += bch.o
 obj-$(CONFIG_MMC_SPI) += crc7.o
-#ifndef CONFIG_TPL_BUILD
-obj-y += crc32.o
-#endif
+obj-$(CONFIG_$(SPL_TPL_)CRC32) += crc32.o
 obj-$(CONFIG_CRC32C) += crc32c.o
 obj-y += ctype.o
 obj-y += div64.o

tools/Kconfig

@@ -9,6 +9,11 @@ config MKIMAGE_DTC_PATH
 	  some cases the system dtc may not support all required features
 	  and the path to a different version should be given here.
 
+config TOOLS_CRC32
+	def_bool y
+	help
+	  Enable CRC32 support in the tools builds
+
 config TOOLS_LIBCRYPTO
 	bool "Use OpenSSL's libcrypto library for host tools"
 	default y