stm32mp1: move check_header() to common code

This function can be used on several stm32mp devices, it is then moved in
plat/st/common/stm32mp_common.c.

Change-Id: I862debe39604410f71a9ddc28713026362e9ecda
Signed-off-by: Yann Gautier <yann.gautier@st.com>

drivers/st/io/io_stm32image.c

@@ -242,40 +242,6 @@ static int stm32image_partition_size(io_entity_t *entity, size_t *length)
 	return 0;
 }
 
-static int check_header(boot_api_image_header_t *header, uintptr_t buffer)
-{
-	uint32_t i;
-	uint32_t img_checksum = 0;
-
-	/*
-	 * Check header/payload validity:
-	 *	- Header magic
-	 *	- Header version
-	 *	- Payload checksum
-	 */
-	if (header->magic != BOOT_API_IMAGE_HEADER_MAGIC_NB) {
-		ERROR("Header magic\n");
-		return -EINVAL;
-	}
-
-	if (header->header_version != BOOT_API_HEADER_VERSION) {
-		ERROR("Header version\n");
-		return -EINVAL;
-	}
-
-	for (i = 0; i < header->image_length; i++) {
-		img_checksum += *(uint8_t *)(buffer + i);
-	}
-
-	if (header->payload_checksum != img_checksum) {
-		ERROR("Checksum: 0x%x (awaited: 0x%x)\n", img_checksum,
-		      header->payload_checksum);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 /* Read data from a partition */
 static int stm32image_partition_read(io_entity_t *entity, uintptr_t buffer,
 				     size_t length, size_t *length_read)
@@ -368,7 +334,7 @@ static int stm32image_partition_read(io_entity_t *entity, uintptr_t buffer,
 			continue;
 		}
 
-		result = check_header(header, buffer);
+		result = stm32mp_check_header(header, buffer);
 		if (result != 0) {
 			ERROR("Header check failed\n");
 			*length_read = 0;

plat/st/common/include/stm32mp_common.h

@@ -10,6 +10,8 @@
 
 #include <stdbool.h>
 
+#include <platform_def.h>
+
 #include <arch_helpers.h>
 
 /* Functions to save and get boot context address given by ROM code */
@@ -94,4 +96,12 @@ static inline bool timeout_elapsed(uint64_t expire)
 	return read_cntpct_el0() > expire;
 }
 
+/*
+ * Check that the STM32 header of a .stm32 binary image is valid
+ * @param header: pointer to the stm32 image header
+ * @param buffer: address of the binary image (payload)
+ * @return: 0 on success, negative value in case of error
+ */
+int stm32mp_check_header(boot_api_image_header_t *header, uintptr_t buffer);
+
 #endif /* STM32MP_COMMON_H */

plat/st/common/stm32mp_common.c

@@ -5,6 +5,7 @@
  */
 
 #include <assert.h>
+#include <errno.h>
 
 #include <platform_def.h>
 
@@ -116,3 +117,37 @@ uint32_t stm32_get_gpio_bank_offset(unsigned int bank)
 
 	return bank * GPIO_BANK_OFFSET;
 }
+
+int stm32mp_check_header(boot_api_image_header_t *header, uintptr_t buffer)
+{
+	uint32_t i;
+	uint32_t img_checksum = 0U;
+
+	/*
+	 * Check header/payload validity:
+	 *	- Header magic
+	 *	- Header version
+	 *	- Payload checksum
+	 */
+	if (header->magic != BOOT_API_IMAGE_HEADER_MAGIC_NB) {
+		ERROR("Header magic\n");
+		return -EINVAL;
+	}
+
+	if (header->header_version != BOOT_API_HEADER_VERSION) {
+		ERROR("Header version\n");
+		return -EINVAL;
+	}
+
+	for (i = 0U; i < header->image_length; i++) {
+		img_checksum += *(uint8_t *)(buffer + i);
+	}
+
+	if (header->payload_checksum != img_checksum) {
+		ERROR("Checksum: 0x%x (awaited: 0x%x)\n", img_checksum,
+		      header->payload_checksum);
+		return -EINVAL;
+	}
+
+	return 0;
+}