[PATCH v6 7/7] rockchip: binman: Support use of crc32 hash for FIT images

[Jonas Karlman]

Use of SHA256 checksum validation on ARMv7 SoCs can be very time
consuming compared to when used on a ARMv8 SoC with Crypto Extensions.

Add support for use of the much faster CRC32 hash algo when SHA256 is
not supported in SPL. Also use FIT_HASH_ALGO to simplify the ifdefs when
no known hash algo has been compiled.

Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
Reviewed-by: Kever Yang <kever.yang at rock-chips.com>
Reviewed-by: Quentin Schulz <quentin.schulz at cherry.de>
---
Changes in v6:
- Drop use of HAS_FIT_HASH
- Collect r-b tag

Changes in v5:
- Update commit message and add comment that CRC32 hash algo should
  only be used for basic checksum validation.
- Collect r-b tag

Changes in v4:
- New patch
---
 arch/arm/dts/rockchip-u-boot.dtsi | 32 +++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/arch/arm/dts/rockchip-u-boot.dtsi b/arch/arm/dts/rockchip-u-boot.dtsi
index f60cc31fb1a6..cc2feed6464f 100644
--- a/arch/arm/dts/rockchip-u-boot.dtsi
+++ b/arch/arm/dts/rockchip-u-boot.dtsi
@@ -19,6 +19,18 @@
 #define FIT_UBOOT_COMP		"none"
 #endif
 
+/*
+ * SHA256 should be enabled in SPL when signature validation is involved,
+ * CRC32 should only be used for basic checksum validation of FIT images.
+ */
+#if defined(CONFIG_SPL_FIT_SIGNATURE)
+#if defined(CONFIG_SPL_SHA256)
+#define FIT_HASH_ALGO		"sha256"
+#elif defined(CONFIG_SPL_CRC32)
+#define FIT_HASH_ALGO		"crc32"
+#endif
+#endif
+
 #if defined(CONFIG_SPL_FIT) && (defined(CONFIG_ARM64) || defined(CONFIG_SPL_OPTEE_IMAGE))
 #define HAS_FIT
 #endif
@@ -55,9 +67,9 @@
 				u-boot-nodtb {
 					compress = FIT_UBOOT_COMP;
 				};
-#ifdef CONFIG_SPL_FIT_SIGNATURE
+#ifdef FIT_HASH_ALGO
 				hash {
-					algo = "sha256";
+					algo = FIT_HASH_ALGO;
 				};
 #endif
 			};
@@ -76,9 +88,9 @@
 
 				atf-bl31 {
 				};
-#ifdef CONFIG_SPL_FIT_SIGNATURE
+#ifdef FIT_HASH_ALGO
 				hash {
-					algo = "sha256";
+					algo = FIT_HASH_ALGO;
 				};
 #endif
 			};
@@ -96,9 +108,9 @@
 				tee-os {
 					optional;
 				};
-#ifdef CONFIG_SPL_FIT_SIGNATURE
+#ifdef FIT_HASH_ALGO
 				hash {
-					algo = "sha256";
+					algo = FIT_HASH_ALGO;
 				};
 #endif
 			};
@@ -114,9 +126,9 @@
 
 				tee-os {
 				};
-#ifdef CONFIG_SPL_FIT_SIGNATURE
+#ifdef FIT_HASH_ALGO
 				hash {
-					algo = "sha256";
+					algo = FIT_HASH_ALGO;
 				};
 #endif
 			};
@@ -126,9 +138,9 @@
 				description = "fdt-NAME";
 				compression = "none";
 				type = "flat_dt";
-#ifdef CONFIG_SPL_FIT_SIGNATURE
+#ifdef FIT_HASH_ALGO
 				hash {
-					algo = "sha256";
+					algo = FIT_HASH_ALGO;
 				};
 #endif
 			};
-- 
2.49.0