Re: [PATCH v5 11/29] image: Use the correct checks for CRC32

[Alex G.]

On 9/25/21 8:43 PM, Simon Glass wrote:
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 <s...@chromium.org>

I'm not entirely convinced, but it does make CRC32 more consistent with 
other hashes.

Reviewed-by: Alexandru Gagniuc <mr.nuke...@gmail.com>

---

Changes in v5:
- Rebase to next
- Use TOOLS_ instead of HOST_

  common/hash.c      | 13 ++++++++-----
  common/spl/Kconfig | 13 ++++++++++++-
  lib/Kconfig        |  5 +++++
  lib/Makefile       |  4 +---
  tools/Kconfig      |  5 +++++
  5 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/common/hash.c b/common/hash.c
index e92f9a9594f..b4b01c193b6 100644
--- a/common/hash.c
+++ b/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 */
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 34f6fc2cfad..91bb6c89fb4 100644
--- a/common/spl/Kconfig
+++ b/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
diff --git a/lib/Kconfig b/lib/Kconfig
index 64765acfa61..70bf8e7a464 100644
--- a/lib/Kconfig
+++ b/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
  
diff --git a/lib/Makefile b/lib/Makefile
index 9c0373e2955..c523bb74119 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -99,9 +99,7 @@ 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
diff --git a/tools/Kconfig b/tools/Kconfig
index 8685c800f93..91ce8ae3e51 100644
--- a/tools/Kconfig
+++ b/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