spl: implement CRC check on U-Boot uImage
SPL currently does not check uImage CRCs when loading U-Boot.
This patch adds checking the uImage CRC when SPL loads U-Boot. It does
this by reusing the existing config option SPL_CRC32_SUPPORT to allow
leaving out the CRC check on boards where the additional code size or
boot time is a problem (adding the CRC check currently adds ~1.4 kByte
to flash).
The SPL_CRC32_SUPPORT config option now gets enabled by default if SPL
support for legacy images is enabled to check the CRC on all boards
that don't actively take countermeasures.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 85edd5a..206c240 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -100,6 +100,16 @@
is y. If this is not set, SPL will move on to other available
boot media to find a suitable image.
+config SPL_LEGACY_IMAGE_CRC_CHECK
+ bool "Check CRC of Legacy images"
+ depends on SPL_LEGACY_IMAGE_SUPPORT
+ select SPL_CRC32_SUPPORT
+ help
+ Enable this to check the CRC of Legacy images. While this increases
+ reliability, it affects both code size and boot duration.
+ If disabled, Legacy images are booted if the image magic and size
+ are correct, without further integrity checks.
+
config SPL_SYS_MALLOC_SIMPLE
bool
prompt "Only use malloc_simple functions in the SPL"
@@ -236,13 +246,13 @@
config SPL_CRC32_SUPPORT
bool "Support CRC32"
- depends on SPL_FIT
+ default y if SPL_LEGACY_IMAGE_SUPPORT
help
- Enable this to support CRC32 in FIT images within SPL. This is a
- 32-bit checksum value that can be used to verify images. This is
- the least secure type of checksum, suitable for detected
- accidental image corruption. For secure applications you should
- consider SHA1 or SHA256.
+ 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 SPL_MD5_SUPPORT
bool "Support MD5"