tools/mkimage: add support for STM32 image format

STM32MP157 bootrom needs a specific header for first boot stage.
This patch adds support of this header in mkimage.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/common/image.c b/common/image.c
index 14be3ca..9e850c0 100644
--- a/common/image.c
+++ b/common/image.c
@@ -161,6 +161,7 @@
 	{       IH_TYPE_TEE,        "tee",        "Trusted Execution Environment Image",},
 	{	IH_TYPE_FIRMWARE_IVT, "firmware_ivt", "Firmware with HABv4 IVT" },
 	{       IH_TYPE_PMMC,        "pmmc",        "TI Power Management Micro-Controller Firmware",},
+	{	IH_TYPE_STM32IMAGE, "stm32image", "STMicroelectronics STM32 Image" },
 	{	-1,		    "",		  "",			},
 };
 
diff --git a/include/image.h b/include/image.h
index 88e17fc..4c278c7 100644
--- a/include/image.h
+++ b/include/image.h
@@ -272,6 +272,7 @@
 	IH_TYPE_TEE,            /* Trusted Execution Environment OS Image */
 	IH_TYPE_FIRMWARE_IVT,		/* Firmware Image with HABv4 IVT */
 	IH_TYPE_PMMC,            /* TI Power Management Micro-Controller Firmware */
+	IH_TYPE_STM32IMAGE,		/* STMicroelectronics STM32 Image */
 
 	IH_TYPE_COUNT,			/* Number of image types */
 };
diff --git a/tools/Makefile b/tools/Makefile
index f38f68e..55efb74 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -103,6 +103,7 @@
 			pblimage.o \
 			pbl_crc32.o \
 			vybridimage.o \
+			stm32image.o \
 			$(ROCKCHIP_OBS) \
 			socfpgaimage.o \
 			lib/sha1.o \
diff --git a/tools/stm32image.c b/tools/stm32image.c
new file mode 100644
index 0000000..437e384
--- /dev/null
+++ b/tools/stm32image.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier:	GPL-2.0+	BSD-3-Clause
+ */
+
+#include <image.h>
+#include "imagetool.h"
+
+/* magic ='S' 'T' 'M' 0x32 */
+#define HEADER_MAGIC be32_to_cpu(0x53544D32)
+#define VER_MAJOR_IDX	2
+#define VER_MINOR_IDX	1
+#define VER_VARIANT_IDX	0
+#define HEADER_VERSION_V1	0x1
+/* default option : bit0 => no signature */
+#define HEADER_DEFAULT_OPTION	(cpu_to_le32(0x00000001))
+
+struct stm32_header {
+	uint32_t magic_number;
+	uint32_t image_signature[64 / 4];
+	uint32_t image_checksum;
+	uint8_t  header_version[4];
+	uint32_t image_length;
+	uint32_t image_entry_point;
+	uint32_t reserved1;
+	uint32_t load_address;
+	uint32_t reserved2;
+	uint32_t version_number;
+	uint32_t option_flags;
+	uint32_t ecdsa_algorithm;
+	uint32_t ecdsa_public_key[64 / 4];
+	uint32_t padding[84 / 4];
+};
+
+static struct stm32_header stm32image_header;
+
+static void stm32image_default_header(struct stm32_header *ptr)
+{
+	if (!ptr)
+		return;
+
+	ptr->magic_number = HEADER_MAGIC;
+	ptr->header_version[VER_MAJOR_IDX] = HEADER_VERSION_V1;
+	ptr->option_flags = HEADER_DEFAULT_OPTION;
+	ptr->ecdsa_algorithm = 1;
+}
+
+static uint32_t stm32image_checksum(void *start, uint32_t len)
+{
+	uint32_t csum = 0;
+	uint32_t hdr_len = sizeof(struct stm32_header);
+	uint8_t *p;
+
+	if (len < hdr_len)
+		return 0;
+
+	p = start + hdr_len;
+	len -= hdr_len;
+
+	while (len > 0) {
+		csum += *p;
+		p++;
+		len--;
+	}
+
+	return csum;
+}
+
+static int stm32image_check_image_types(uint8_t type)
+{
+	if (type == IH_TYPE_STM32IMAGE)
+		return EXIT_SUCCESS;
+	return EXIT_FAILURE;
+}
+
+static int stm32image_verify_header(unsigned char *ptr, int image_size,
+				    struct image_tool_params *params)
+{
+	struct stm32_header *stm32hdr = (struct stm32_header *)ptr;
+	int i;
+
+	if (image_size < sizeof(struct stm32_header))
+		return -1;
+	if (stm32hdr->magic_number != HEADER_MAGIC)
+		return -1;
+	if (stm32hdr->header_version[VER_MAJOR_IDX] != HEADER_VERSION_V1)
+		return -1;
+	if (stm32hdr->reserved1 || stm32hdr->reserved2)
+		return -1;
+	for (i = 0; i < (sizeof(stm32hdr->padding) / 4); i++) {
+		if (stm32hdr->padding[i] != 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static void stm32image_print_header(const void *ptr)
+{
+	struct stm32_header *stm32hdr = (struct stm32_header *)ptr;
+
+	printf("Image Type   : STMicroelectronics STM32 V%d.%d\n",
+	       stm32hdr->header_version[VER_MAJOR_IDX],
+	       stm32hdr->header_version[VER_MINOR_IDX]);
+	printf("Image Size   : %lu bytes\n",
+	       (unsigned long)le32_to_cpu(stm32hdr->image_length));
+	printf("Image Load   : 0x%08x\n",
+	       le32_to_cpu(stm32hdr->load_address));
+	printf("Entry Point  : 0x%08x\n",
+	       le32_to_cpu(stm32hdr->image_entry_point));
+	printf("Checksum     : 0x%08x\n",
+	       le32_to_cpu(stm32hdr->image_checksum));
+	printf("Option     : 0x%08x\n",
+	       le32_to_cpu(stm32hdr->option_flags));
+}
+
+static void stm32image_set_header(void *ptr, struct stat *sbuf, int ifd,
+				  struct image_tool_params *params)
+{
+	struct stm32_header *stm32hdr = (struct stm32_header *)ptr;
+
+	stm32image_default_header(stm32hdr);
+
+	stm32hdr->load_address = cpu_to_le32(params->addr);
+	stm32hdr->image_entry_point = cpu_to_le32(params->ep);
+	stm32hdr->image_length = cpu_to_le32((uint32_t)sbuf->st_size -
+					     sizeof(struct stm32_header));
+	stm32hdr->image_checksum = stm32image_checksum(ptr, sbuf->st_size);
+}
+
+/*
+ * stm32image parameters
+ */
+U_BOOT_IMAGE_TYPE(
+	stm32image,
+	"STMicroelectronics STM32MP Image support",
+	sizeof(struct stm32_header),
+	(void *)&stm32image_header,
+	NULL,
+	stm32image_verify_header,
+	stm32image_print_header,
+	stm32image_set_header,
+	NULL,
+	stm32image_check_image_types,
+	NULL,
+	NULL
+);