diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d692139199c..799fe7d43af 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1014,6 +1014,7 @@ config ARCH_SUNXI
 	select SUNXI_GPIO
 	select SYS_NS16550
 	select SYS_THUMB_BUILD if !ARM64
+	select TOOLS_LIBCRYPTO
 	select USB if DISTRO_DEFAULTS
 	select USB_KEYBOARD if DISTRO_DEFAULTS && USB_HOST
 	select USB_STORAGE if DISTRO_DEFAULTS && USB_HOST
diff --git a/common/image.c b/common/image.c
index 59c52a1f9ad..8f1634c1206 100644
--- a/common/image.c
+++ b/common/image.c
@@ -191,6 +191,7 @@ static const table_entry_t uimage_type[] = {
 	{	IH_TYPE_MTKIMAGE,   "mtk_image",   "MediaTek BootROM loadable Image" },
 	{	IH_TYPE_COPRO, "copro", "Coprocessor Image"},
 	{	IH_TYPE_SUNXI_EGON, "sunxi_egon",  "Allwinner eGON Boot Image" },
+	{	IH_TYPE_SUNXI_TOC0, "sunxi_toc0",  "Allwinner TOC0 Boot Image" },
 	{	-1,		    "",		  "",			},
 };
 
diff --git a/include/image.h b/include/image.h
index e20f0b69d58..a4efc090309 100644
--- a/include/image.h
+++ b/include/image.h
@@ -284,6 +284,7 @@ enum {
 	IH_TYPE_IMX8IMAGE,		/* Freescale IMX8Boot Image	*/
 	IH_TYPE_COPRO,			/* Coprocessor Image for remoteproc*/
 	IH_TYPE_SUNXI_EGON,		/* Allwinner eGON Boot Image */
+	IH_TYPE_SUNXI_TOC0,		/* Allwinner TOC0 Boot Image */
 
 	IH_TYPE_COUNT,			/* Number of image types */
 };
diff --git a/include/sunxi_image.h b/include/sunxi_image.h
index 5b2055c0af3..399ad0be999 100644
--- a/include/sunxi_image.h
+++ b/include/sunxi_image.h
@@ -9,9 +9,12 @@
  *
  * Shared between mkimage and the SPL.
  */
+
 #ifndef	SUNXI_IMAGE_H
 #define	SUNXI_IMAGE_H
 
+#include <linux/types.h>
+
 #define BOOT0_MAGIC		"eGON.BT0"
 #define BROM_STAMP_VALUE	0x5f0a6c39
 #define SPL_SIGNATURE		"SPL" /* marks "sunxi" SPL header */
@@ -79,4 +82,37 @@ struct boot_file_head {
 /* Compile time check to assure proper alignment of structure */
 typedef char boot_file_head_not_multiple_of_32[1 - 2*(sizeof(struct boot_file_head) % 32)];
 
+struct toc0_main_info {
+	uint8_t	name[8];
+	__le32	magic;
+	__le32	checksum;
+	__le32	serial;
+	__le32	status;
+	__le32	num_items;
+	__le32	length;
+	uint8_t	platform[4];
+	uint8_t	reserved[8];
+	uint8_t	end[4];
+};
+
+#define TOC0_MAIN_INFO_NAME		"TOC0.GLH"
+#define TOC0_MAIN_INFO_MAGIC		0x89119800
+#define TOC0_MAIN_INFO_END		"MIE;"
+
+struct toc0_item_info {
+	__le32	name;
+	__le32	offset;
+	__le32	length;
+	__le32	status;
+	__le32	type;
+	__le32	load_addr;
+	uint8_t	reserved[4];
+	uint8_t	end[4];
+};
+
+#define TOC0_ITEM_INFO_NAME_CERT	0x00010101
+#define TOC0_ITEM_INFO_NAME_FIRMWARE	0x00010202
+#define TOC0_ITEM_INFO_NAME_KEY		0x00010303
+#define TOC0_ITEM_INFO_END		"IIE;"
+
 #endif
diff --git a/tools/Makefile b/tools/Makefile
index ad0e9cf9490..fc3b66af6af 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -98,7 +98,8 @@ AES_OBJS-$(CONFIG_TOOLS_LIBCRYPTO) := $(addprefix lib/aes/, \
 LIBCRYPTO_OBJS-$(CONFIG_TOOLS_LIBCRYPTO) := \
 			lib/fdt-libcrypto.o \
 			kwbimage.o \
-			mxsimage.o
+			mxsimage.o \
+			sunxi_toc0.o
 
 ROCKCHIP_OBS = lib/rc4.o rkcommon.o rkimage.o rksd.o rkspi.o
 
diff --git a/tools/sunxi_toc0.c b/tools/sunxi_toc0.c
new file mode 100644
index 00000000000..5aa39cba775
--- /dev/null
+++ b/tools/sunxi_toc0.c
@@ -0,0 +1,907 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018 Arm Ltd.
+ * (C) Copyright 2020-2021 Samuel Holland <samuel@sholland.org>
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <openssl/asn1t.h>
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+
+#include <image.h>
+#include <sunxi_image.h>
+
+#include "imagetool.h"
+#include "mkimage.h"
+
+/*
+ * NAND requires 8K padding. For other devices, BROM requires only
+ * 512B padding, but let's use the larger padding to cover everything.
+ */
+#define PAD_SIZE		8192
+
+#define pr_fmt(fmt)		"mkimage (TOC0): %s: " fmt
+#define pr_err(fmt, args...)	fprintf(stderr, pr_fmt(fmt), "error", ##args)
+#define pr_warn(fmt, args...)	fprintf(stderr, pr_fmt(fmt), "warning", ##args)
+#define pr_info(fmt, args...)	fprintf(stderr, pr_fmt(fmt), "info", ##args)
+
+struct toc0_key_item {
+	__le32  vendor_id;
+	__le32  key0_n_len;
+	__le32  key0_e_len;
+	__le32  key1_n_len;
+	__le32  key1_e_len;
+	__le32  sig_len;
+	uint8_t key0[512];
+	uint8_t key1[512];
+	uint8_t reserved[32];
+	uint8_t sig[256];
+};
+
+/*
+ * This looks somewhat like an X.509 certificate, but it is not valid BER.
+ *
+ * Some differences:
+ *  - Some X.509 certificate fields are missing or rearranged.
+ *  - Some sequences have the wrong tag.
+ *  - Zero-length sequences are accepted.
+ *  - Large strings and integers must be an even number of bytes long.
+ *  - Positive integers are not zero-extended to maintain their sign.
+ *
+ * See https://linux-sunxi.org/TOC0 for more information.
+ */
+struct toc0_small_tag {
+	uint8_t tag;
+	uint8_t length;
+};
+
+typedef struct toc0_small_tag toc0_small_int;
+typedef struct toc0_small_tag toc0_small_oct;
+typedef struct toc0_small_tag toc0_small_seq;
+typedef struct toc0_small_tag toc0_small_exp;
+
+#define TOC0_SMALL_INT(len) { 0x02, (len) }
+#define TOC0_SMALL_SEQ(len) { 0x30, (len) }
+#define TOC0_SMALL_EXP(tag, len) { 0xa0 | (tag), len }
+
+struct toc0_large_tag {
+	uint8_t tag;
+	uint8_t prefix;
+	uint8_t length_hi;
+	uint8_t length_lo;
+};
+
+typedef struct toc0_large_tag toc0_large_int;
+typedef struct toc0_large_tag toc0_large_bit;
+typedef struct toc0_large_tag toc0_large_seq;
+
+#define TOC0_LARGE_INT(len) { 0x02, 0x82, (len) >> 8, (len) & 0xff }
+#define TOC0_LARGE_BIT(len) { 0x03, 0x82, (len) >> 8, (len) & 0xff }
+#define TOC0_LARGE_SEQ(len) { 0x30, 0x82, (len) >> 8, (len) & 0xff }
+
+struct toc0_cert_item {
+	toc0_large_seq tag_totalSequence;
+	struct toc0_totalSequence {
+		toc0_large_seq tag_mainSequence;
+		struct toc0_mainSequence {
+			toc0_small_exp tag_explicit0;
+			struct toc0_explicit0 {
+				toc0_small_int tag_version;
+				uint8_t version;
+			} explicit0;
+			toc0_small_int tag_serialNumber;
+			uint8_t serialNumber;
+			toc0_small_seq tag_signature;
+			toc0_small_seq tag_issuer;
+			toc0_small_seq tag_validity;
+			toc0_small_seq tag_subject;
+			toc0_large_seq tag_subjectPublicKeyInfo;
+			struct toc0_subjectPublicKeyInfo {
+				toc0_small_seq tag_algorithm;
+				toc0_large_seq tag_publicKey;
+				struct toc0_publicKey {
+					toc0_large_int tag_n;
+					uint8_t n[256];
+					toc0_small_int tag_e;
+					uint8_t e[3];
+				} publicKey;
+			} subjectPublicKeyInfo;
+			toc0_small_exp tag_explicit3;
+			struct toc0_explicit3 {
+				toc0_small_seq tag_extension;
+				struct toc0_extension {
+					toc0_small_int tag_digest;
+					uint8_t digest[32];
+				} extension;
+			} explicit3;
+		} mainSequence;
+		toc0_large_bit tag_sigSequence;
+		struct toc0_sigSequence {
+			toc0_small_seq tag_algorithm;
+			toc0_large_bit tag_signature;
+			uint8_t signature[256];
+		} sigSequence;
+	} totalSequence;
+};
+
+#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
+
+static const struct toc0_cert_item cert_item_template = {
+	TOC0_LARGE_SEQ(sizeof(struct toc0_totalSequence)),
+	{
+		TOC0_LARGE_SEQ(sizeof(struct toc0_mainSequence)),
+		{
+			TOC0_SMALL_EXP(0, sizeof(struct toc0_explicit0)),
+			{
+				TOC0_SMALL_INT(sizeof_field(struct toc0_explicit0, version)),
+				0,
+			},
+			TOC0_SMALL_INT(sizeof_field(struct toc0_mainSequence, serialNumber)),
+			0,
+			TOC0_SMALL_SEQ(0),
+			TOC0_SMALL_SEQ(0),
+			TOC0_SMALL_SEQ(0),
+			TOC0_SMALL_SEQ(0),
+			TOC0_LARGE_SEQ(sizeof(struct toc0_subjectPublicKeyInfo)),
+			{
+				TOC0_SMALL_SEQ(0),
+				TOC0_LARGE_SEQ(sizeof(struct toc0_publicKey)),
+				{
+					TOC0_LARGE_INT(sizeof_field(struct toc0_publicKey, n)),
+					{},
+					TOC0_SMALL_INT(sizeof_field(struct toc0_publicKey, e)),
+					{},
+				},
+			},
+			TOC0_SMALL_EXP(3, sizeof(struct toc0_explicit3)),
+			{
+				TOC0_SMALL_SEQ(sizeof(struct toc0_extension)),
+				{
+					TOC0_SMALL_INT(sizeof_field(struct toc0_extension, digest)),
+					{},
+				},
+			},
+		},
+		TOC0_LARGE_BIT(sizeof(struct toc0_sigSequence)),
+		{
+			TOC0_SMALL_SEQ(0),
+			TOC0_LARGE_BIT(sizeof_field(struct toc0_sigSequence, signature)),
+			{},
+		},
+	},
+};
+
+#define TOC0_DEFAULT_NUM_ITEMS		3
+#define TOC0_DEFAULT_HEADER_LEN						  \
+	ALIGN(								  \
+		sizeof(struct toc0_main_info)				+ \
+		sizeof(struct toc0_item_info) *	TOC0_DEFAULT_NUM_ITEMS	+ \
+		sizeof(struct toc0_cert_item)				+ \
+		sizeof(struct toc0_key_item),				  \
+	32)
+
+static char *fw_key_file   = "fw_key.pem";
+static char *key_item_file = "key_item.bin";
+static char *root_key_file = "root_key.pem";
+
+/*
+ * Create a key item in @buf, containing the public keys @root_key and @fw_key,
+ * and signed by the RSA key @root_key.
+ */
+static int toc0_create_key_item(uint8_t *buf, uint32_t *len,
+				RSA *root_key, RSA *fw_key)
+{
+	struct toc0_key_item *key_item = (void *)buf;
+	uint8_t digest[SHA256_DIGEST_LENGTH];
+	int ret = EXIT_FAILURE;
+	unsigned int sig_len;
+	int n_len, e_len;
+
+	/* Store key 0. */
+	n_len = BN_bn2bin(RSA_get0_n(root_key), key_item->key0);
+	e_len = BN_bn2bin(RSA_get0_e(root_key), key_item->key0 + n_len);
+	if (n_len + e_len > sizeof(key_item->key0)) {
+		pr_err("Root key is too big for key item\n");
+		goto err;
+	}
+	key_item->key0_n_len = cpu_to_le32(n_len);
+	key_item->key0_e_len = cpu_to_le32(e_len);
+
+	/* Store key 1. */
+	n_len = BN_bn2bin(RSA_get0_n(fw_key), key_item->key1);
+	e_len = BN_bn2bin(RSA_get0_e(fw_key), key_item->key1 + n_len);
+	if (n_len + e_len > sizeof(key_item->key1)) {
+		pr_err("Firmware key is too big for key item\n");
+		goto err;
+	}
+	key_item->key1_n_len = cpu_to_le32(n_len);
+	key_item->key1_e_len = cpu_to_le32(e_len);
+
+	/* Sign the key item. */
+	key_item->sig_len = cpu_to_le32(RSA_size(root_key));
+	SHA256(buf, key_item->sig - buf, digest);
+	if (!RSA_sign(NID_sha256, digest, sizeof(digest),
+		      key_item->sig, &sig_len, root_key)) {
+		pr_err("Failed to sign key item\n");
+		goto err;
+	}
+	if (sig_len != sizeof(key_item->sig)) {
+		pr_err("Bad key item signature length\n");
+		goto err;
+	}
+
+	*len = sizeof(*key_item);
+	ret = EXIT_SUCCESS;
+
+err:
+	return ret;
+}
+
+/*
+ * Verify the key item in @buf, containing two public keys @key0 and @key1,
+ * and signed by the RSA key @key0. If @root_key is provided, only signatures
+ * by that key will be accepted. @key1 is returned in @key.
+ */
+static int toc0_verify_key_item(const uint8_t *buf, uint32_t len,
+				RSA *root_key, RSA **fw_key)
+{
+	struct toc0_key_item *key_item = (void *)buf;
+	uint8_t digest[SHA256_DIGEST_LENGTH];
+	int ret = EXIT_FAILURE;
+	int n_len, e_len;
+	RSA *key0 = NULL;
+	RSA *key1 = NULL;
+	BIGNUM *n, *e;
+
+	if (len < sizeof(*key_item))
+		goto err;
+
+	/* Load key 0. */
+	n_len = le32_to_cpu(key_item->key0_n_len);
+	e_len = le32_to_cpu(key_item->key0_e_len);
+	if (n_len + e_len > sizeof(key_item->key0)) {
+		pr_err("Bad root key size in key item\n");
+		goto err;
+	}
+	n = BN_bin2bn(key_item->key0, n_len, NULL);
+	e = BN_bin2bn(key_item->key0 + n_len, e_len, NULL);
+	key0 = RSA_new();
+	if (!key0)
+		goto err;
+	if (!RSA_set0_key(key0, n, e, NULL))
+		goto err;
+
+	/* If a root key was provided, compare it to key 0. */
+	if (root_key && (BN_cmp(n, RSA_get0_n(root_key)) ||
+			 BN_cmp(e, RSA_get0_e(root_key)))) {
+		pr_err("Wrong root key in key item\n");
+		goto err;
+	}
+
+	/* Verify the key item signature. */
+	SHA256(buf, key_item->sig - buf, digest);
+	if (!RSA_verify(NID_sha256, digest, sizeof(digest),
+			key_item->sig, le32_to_cpu(key_item->sig_len), key0)) {
+		pr_err("Bad key item signature\n");
+		goto err;
+	}
+
+	if (fw_key) {
+		/* Load key 1. */
+		n_len = le32_to_cpu(key_item->key1_n_len);
+		e_len = le32_to_cpu(key_item->key1_e_len);
+		if (n_len + e_len > sizeof(key_item->key1)) {
+			pr_err("Bad firmware key size in key item\n");
+			goto err;
+		}
+		n = BN_bin2bn(key_item->key1, n_len, NULL);
+		e = BN_bin2bn(key_item->key1 + n_len, e_len, NULL);
+		key1 = RSA_new();
+		if (!key1)
+			goto err;
+		if (!RSA_set0_key(key1, n, e, NULL))
+			goto err;
+
+		if (*fw_key) {
+			/* If a FW key was provided, compare it to key 1. */
+			if (BN_cmp(n, RSA_get0_n(*fw_key)) ||
+			    BN_cmp(e, RSA_get0_e(*fw_key))) {
+				pr_err("Wrong firmware key in key item\n");
+				goto err;
+			}
+		} else {
+			/* Otherwise, send key1 back to the caller. */
+			*fw_key = key1;
+			key1 = NULL;
+		}
+	}
+
+	ret = EXIT_SUCCESS;
+
+err:
+	RSA_free(key0);
+	RSA_free(key1);
+
+	return ret;
+}
+
+/*
+ * Create a certificate in @buf, describing the firmware with SHA256 digest
+ * @digest, and signed by the RSA key @fw_key.
+ */
+static int toc0_create_cert_item(uint8_t *buf, uint32_t *len, RSA *fw_key,
+				 uint8_t digest[static SHA256_DIGEST_LENGTH])
+{
+	struct toc0_cert_item *cert_item = (void *)buf;
+	uint8_t cert_digest[SHA256_DIGEST_LENGTH];
+	struct toc0_totalSequence *totalSequence;
+	struct toc0_sigSequence *sigSequence;
+	struct toc0_extension *extension;
+	struct toc0_publicKey *publicKey;
+	int ret = EXIT_FAILURE;
+	unsigned int sig_len;
+
+	memcpy(cert_item, &cert_item_template, sizeof(*cert_item));
+	*len = sizeof(*cert_item);
+
+	/*
+	 * Fill in the public key.
+	 *
+	 * Only 2048-bit RSA keys are supported. Since this uses a fixed-size
+	 * structure, it may fail for non-standard exponents.
+	 */
+	totalSequence = &cert_item->totalSequence;
+	publicKey = &totalSequence->mainSequence.subjectPublicKeyInfo.publicKey;
+	if (BN_bn2binpad(RSA_get0_n(fw_key), publicKey->n, sizeof(publicKey->n)) < 0 ||
+	    BN_bn2binpad(RSA_get0_e(fw_key), publicKey->e, sizeof(publicKey->e)) < 0) {
+		pr_err("Firmware key is too big for certificate\n");
+		goto err;
+	}
+
+	/* Fill in the firmware digest. */
+	extension = &totalSequence->mainSequence.explicit3.extension;
+	memcpy(&extension->digest, digest, SHA256_DIGEST_LENGTH);
+
+	/*
+	 * Sign the certificate.
+	 *
+	 * In older SBROM versions (and by default in newer versions),
+	 * the last 4 bytes of the certificate are not signed.
+	 *
+	 * (The buffer passed to SHA256 starts at tag_mainSequence, but
+	 *  the buffer size does not include the length of that tag.)
+	 */
+	SHA256((uint8_t *)totalSequence, sizeof(struct toc0_mainSequence), cert_digest);
+	sigSequence = &totalSequence->sigSequence;
+	if (!RSA_sign(NID_sha256, cert_digest, SHA256_DIGEST_LENGTH,
+		      sigSequence->signature, &sig_len, fw_key)) {
+		pr_err("Failed to sign certificate\n");
+		goto err;
+	}
+	if (sig_len != sizeof(sigSequence->signature)) {
+		pr_err("Bad certificate signature length\n");
+		goto err;
+	}
+
+	ret = EXIT_SUCCESS;
+
+err:
+	return ret;
+}
+
+/*
+ * Verify the certificate in @buf, describing the firmware with SHA256 digest
+ * @digest, and signed by the RSA key contained within. If @fw_key is provided,
+ * only that key will be accepted.
+ *
+ * This function is only expected to work with images created by mkimage.
+ */
+static int toc0_verify_cert_item(const uint8_t *buf, uint32_t len, RSA *fw_key,
+				 uint8_t digest[static SHA256_DIGEST_LENGTH])
+{
+	const struct toc0_cert_item *cert_item = (const void *)buf;
+	uint8_t cert_digest[SHA256_DIGEST_LENGTH];
+	const struct toc0_totalSequence *totalSequence;
+	const struct toc0_sigSequence *sigSequence;
+	const struct toc0_extension *extension;
+	const struct toc0_publicKey *publicKey;
+	int ret = EXIT_FAILURE;
+	RSA *key = NULL;
+	BIGNUM *n, *e;
+
+	/* Extract the public key from the certificate. */
+	totalSequence = &cert_item->totalSequence;
+	publicKey = &totalSequence->mainSequence.subjectPublicKeyInfo.publicKey;
+	n = BN_bin2bn(publicKey->n, sizeof(publicKey->n), NULL);
+	e = BN_bin2bn(publicKey->e, sizeof(publicKey->e), NULL);
+	key = RSA_new();
+	if (!key)
+		goto err;
+	if (!RSA_set0_key(key, n, e, NULL))
+		goto err;
+
+	/* If a key was provided, compare it to the embedded key. */
+	if (fw_key && (BN_cmp(RSA_get0_n(key), RSA_get0_n(fw_key)) ||
+		       BN_cmp(RSA_get0_e(key), RSA_get0_e(fw_key)))) {
+		pr_err("Wrong firmware key in certificate\n");
+		goto err;
+	}
+
+	/* If a digest was provided, compare it to the embedded digest. */
+	extension = &totalSequence->mainSequence.explicit3.extension;
+	if (digest && memcmp(&extension->digest, digest, SHA256_DIGEST_LENGTH)) {
+		pr_err("Wrong firmware digest in certificate\n");
+		goto err;
+	}
+
+	/* Verify the certificate's signature. See the comment above. */
+	SHA256((uint8_t *)totalSequence, sizeof(struct toc0_mainSequence), cert_digest);
+	sigSequence = &totalSequence->sigSequence;
+	if (!RSA_verify(NID_sha256, cert_digest, SHA256_DIGEST_LENGTH,
+			sigSequence->signature,
+			sizeof(sigSequence->signature), key)) {
+		pr_err("Bad certificate signature\n");
+		goto err;
+	}
+
+	ret = EXIT_SUCCESS;
+
+err:
+	RSA_free(key);
+
+	return ret;
+}
+
+/*
+ * Always create a TOC0 containing 3 items. The extra item will be ignored on
+ * SoCs which do not support it.
+ */
+static int toc0_create(uint8_t *buf, uint32_t len, RSA *root_key, RSA *fw_key,
+		       uint8_t *key_item, uint32_t key_item_len,
+		       uint8_t *fw_item, uint32_t fw_item_len, uint32_t fw_addr)
+{
+	struct toc0_main_info *main_info = (void *)buf;
+	struct toc0_item_info *item_info = (void *)(main_info + 1);
+	uint8_t digest[SHA256_DIGEST_LENGTH];
+	uint32_t *buf32 = (void *)buf;
+	RSA *orig_fw_key = fw_key;
+	int ret = EXIT_FAILURE;
+	uint32_t checksum = 0;
+	uint32_t item_offset;
+	uint32_t item_length;
+	int i;
+
+	/* Hash the firmware for inclusion in the certificate. */
+	SHA256(fw_item, fw_item_len, digest);
+
+	/* Create the main TOC0 header, containing three items. */
+	memcpy(main_info->name, TOC0_MAIN_INFO_NAME, sizeof(main_info->name));
+	main_info->magic	= cpu_to_le32(TOC0_MAIN_INFO_MAGIC);
+	main_info->checksum	= cpu_to_le32(BROM_STAMP_VALUE);
+	main_info->num_items	= cpu_to_le32(TOC0_DEFAULT_NUM_ITEMS);
+	memcpy(main_info->end, TOC0_MAIN_INFO_END, sizeof(main_info->end));
+
+	/* The first item links the ROTPK to the signing key. */
+	item_offset = sizeof(*main_info) +
+		      sizeof(*item_info) * TOC0_DEFAULT_NUM_ITEMS;
+	/* Using an existing key item avoids needing the root private key. */
+	if (key_item) {
+		item_length = sizeof(*key_item);
+		if (toc0_verify_key_item(key_item, item_length,
+					 root_key, &fw_key))
+			goto err;
+		memcpy(buf + item_offset, key_item, item_length);
+	} else if (toc0_create_key_item(buf + item_offset, &item_length,
+					root_key, fw_key)) {
+		goto err;
+	}
+
+	item_info->name		= cpu_to_le32(TOC0_ITEM_INFO_NAME_KEY);
+	item_info->offset	= cpu_to_le32(item_offset);
+	item_info->length	= cpu_to_le32(item_length);
+	memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
+
+	/* The second item contains a certificate signed by the firmware key. */
+	item_offset = item_offset + item_length;
+	if (toc0_create_cert_item(buf + item_offset, &item_length,
+				  fw_key, digest))
+		goto err;
+
+	item_info++;
+	item_info->name		= cpu_to_le32(TOC0_ITEM_INFO_NAME_CERT);
+	item_info->offset	= cpu_to_le32(item_offset);
+	item_info->length	= cpu_to_le32(item_length);
+	memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
+
+	/* The third item contains the actual boot code. */
+	item_offset = ALIGN(item_offset + item_length, 32);
+	item_length = fw_item_len;
+	if (buf + item_offset != fw_item)
+		memmove(buf + item_offset, fw_item, item_length);
+
+	item_info++;
+	item_info->name		= cpu_to_le32(TOC0_ITEM_INFO_NAME_FIRMWARE);
+	item_info->offset	= cpu_to_le32(item_offset);
+	item_info->length	= cpu_to_le32(item_length);
+	item_info->load_addr	= cpu_to_le32(fw_addr);
+	memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
+
+	/* Pad to the required block size with 0xff to be flash-friendly. */
+	item_offset = item_offset + item_length;
+	item_length = ALIGN(item_offset, PAD_SIZE) - item_offset;
+	memset(buf + item_offset, 0xff, item_length);
+
+	/* Fill in the total padded file length. */
+	item_offset = item_offset + item_length;
+	main_info->length = cpu_to_le32(item_offset);
+
+	/* Verify enough space was provided when creating the image. */
+	assert(len >= item_offset);
+
+	/* Calculate the checksum. Yes, it's that simple. */
+	for (i = 0; i < item_offset / 4; ++i)
+		checksum += le32_to_cpu(buf32[i]);
+	main_info->checksum = cpu_to_le32(checksum);
+
+	ret = EXIT_SUCCESS;
+
+err:
+	if (fw_key != orig_fw_key)
+		RSA_free(fw_key);
+
+	return ret;
+}
+
+static const struct toc0_item_info *
+toc0_find_item(const struct toc0_main_info *main_info, uint32_t name,
+	       uint32_t *offset, uint32_t *length)
+{
+	const struct toc0_item_info *item_info = (void *)(main_info + 1);
+	uint32_t item_offset, item_length;
+	uint32_t num_items, main_length;
+	int i;
+
+	num_items   = le32_to_cpu(main_info->num_items);
+	main_length = le32_to_cpu(main_info->length);
+
+	for (i = 0; i < num_items; ++i, ++item_info) {
+		if (le32_to_cpu(item_info->name) != name)
+			continue;
+
+		item_offset = le32_to_cpu(item_info->offset);
+		item_length = le32_to_cpu(item_info->length);
+
+		if (item_offset > main_length ||
+		    item_length > main_length - item_offset)
+			continue;
+
+		*offset = item_offset;
+		*length = item_length;
+
+		return item_info;
+	}
+
+	return NULL;
+}
+
+static int toc0_verify(const uint8_t *buf, uint32_t len, RSA *root_key)
+{
+	const struct toc0_main_info *main_info = (void *)buf;
+	const struct toc0_item_info *item_info;
+	uint8_t digest[SHA256_DIGEST_LENGTH];
+	uint32_t main_length = le32_to_cpu(main_info->length);
+	uint32_t checksum = BROM_STAMP_VALUE;
+	uint32_t *buf32 = (void *)buf;
+	uint32_t length, offset;
+	int ret = EXIT_FAILURE;
+	RSA *fw_key = NULL;
+	int i;
+
+	if (len < main_length)
+		goto err;
+
+	/* Verify the main header. */
+	if (memcmp(main_info->name, TOC0_MAIN_INFO_NAME, sizeof(main_info->name)))
+		goto err;
+	if (le32_to_cpu(main_info->magic) != TOC0_MAIN_INFO_MAGIC)
+		goto err;
+	/* Verify the checksum without modifying the buffer. */
+	for (i = 0; i < main_length / 4; ++i)
+		checksum += le32_to_cpu(buf32[i]);
+	if (checksum != 2 * le32_to_cpu(main_info->checksum))
+		goto err;
+	/* The length must be at least 512 byte aligned. */
+	if (main_length % 512)
+		goto err;
+	if (memcmp(main_info->end, TOC0_MAIN_INFO_END, sizeof(main_info->end)))
+		goto err;
+
+	/* Verify the key item if present (it is optional). */
+	item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_KEY,
+				   &offset, &length);
+	if (!item_info)
+		fw_key = root_key;
+	else if (toc0_verify_key_item(buf + offset, length, root_key, &fw_key))
+		goto err;
+
+	/* Hash the firmware to compare with the certificate. */
+	item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_FIRMWARE,
+				   &offset, &length);
+	if (!item_info) {
+		pr_err("Missing firmware item\n");
+		goto err;
+	}
+	SHA256(buf + offset, length, digest);
+
+	/* Verify the certificate item. */
+	item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_CERT,
+				   &offset, &length);
+	if (!item_info) {
+		pr_err("Missing certificate item\n");
+		goto err;
+	}
+	if (toc0_verify_cert_item(buf + offset, length, fw_key, digest))
+		goto err;
+
+	ret = EXIT_SUCCESS;
+
+err:
+	if (fw_key != root_key)
+		RSA_free(fw_key);
+
+	return ret;
+}
+
+static int toc0_check_params(struct image_tool_params *params)
+{
+	if (!params->dflag)
+		return -EINVAL;
+
+	/*
+	 * If a key directory was provided, look for key files there.
+	 * Otherwise, look for them in the current directory. The key files are
+	 * the "quoted" terms in the description below.
+	 *
+	 * A summary of the chain of trust on most SoCs:
+	 *  1) eFuse contains a SHA256 digest of the public "root key".
+	 *  2) Private "root key" signs the certificate item (generated here).
+	 *  3) Certificate item contains a SHA256 digest of the firmware item.
+	 *
+	 * A summary of the chain of trust on the H6 (by default; a bit in the
+	 * BROM_CONFIG eFuse makes it work like above):
+	 *  1) eFuse contains a SHA256 digest of the public "root key".
+	 *  2) Private "root key" signs the "key item" (generated here).
+	 *  3) "Key item" contains the public "root key" and public "fw key".
+	 *  4) Private "fw key" signs the certificate item (generated here).
+	 *  5) Certificate item contains a SHA256 digest of the firmware item.
+	 *
+	 * This means there are three valid ways to generate a TOC0:
+	 *  1) Provide the private "root key" only. This works everywhere.
+	 *     For H6, the "root key" will also be used as the "fw key".
+	 *  2) FOR H6 ONLY: Provide the private "root key" and a separate
+	 *     private "fw key".
+	 *  3) FOR H6 ONLY: Provide the private "fw key" and a pre-existing
+	 *     "key item" containing the corresponding  public "fw key".
+	 *     In this case, the private "root key" can be kept offline. The
+	 *     "key item" can be extracted from a TOC0 image generated using
+	 *     method #2 above.
+	 *
+	 *  Note that until the ROTPK_HASH eFuse is programmed, any "root key"
+	 *  will be accepted by the BROM.
+	 */
+	if (params->keydir) {
+		if (asprintf(&fw_key_file, "%s/%s", params->keydir, fw_key_file) < 0)
+			return -ENOMEM;
+		if (asprintf(&key_item_file, "%s/%s", params->keydir, key_item_file) < 0)
+			return -ENOMEM;
+		if (asprintf(&root_key_file, "%s/%s", params->keydir, root_key_file) < 0)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int toc0_verify_header(unsigned char *buf, int image_size,
+			      struct image_tool_params *params)
+{
+	int ret = EXIT_FAILURE;
+	RSA *root_key = NULL;
+	FILE *fp;
+
+	/* A root public key is optional. */
+	fp = fopen(root_key_file, "rb");
+	if (fp) {
+		pr_info("Verifying image with existing root key\n");
+		root_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+		if (!root_key)
+			root_key = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL);
+		fclose(fp);
+		if (!root_key) {
+			pr_err("Failed to read public key from '%s'\n",
+			       root_key_file);
+			goto err;
+		}
+	}
+
+	ret = toc0_verify(buf, image_size, root_key);
+
+err:
+	RSA_free(root_key);
+
+	return ret;
+}
+
+static const char *toc0_item_name(uint32_t name)
+{
+	if (name == TOC0_ITEM_INFO_NAME_CERT)
+		return "Certificate";
+	if (name == TOC0_ITEM_INFO_NAME_FIRMWARE)
+		return "Firmware";
+	if (name == TOC0_ITEM_INFO_NAME_KEY)
+		return "Key";
+	return "(unknown)";
+}
+
+static void toc0_print_header(const void *buf)
+{
+	const struct toc0_main_info *main_info = buf;
+	const struct toc0_item_info *item_info = (void *)(main_info + 1);
+	uint32_t head_length, main_length, num_items;
+	uint32_t item_offset, item_length, item_name;
+	int load_addr = -1;
+	int i;
+
+	num_items   = le32_to_cpu(main_info->num_items);
+	head_length = sizeof(*main_info) + num_items * sizeof(*item_info);
+	main_length = le32_to_cpu(main_info->length);
+
+	printf("Allwinner TOC0 Image\n"
+	       "Size: %d bytes\n"
+	       "Contents: %d items\n"
+	       " 00000000:%08x Headers\n",
+	       main_length, num_items, head_length);
+
+	for (i = 0; i < num_items; ++i, ++item_info) {
+		item_offset = le32_to_cpu(item_info->offset);
+		item_length = le32_to_cpu(item_info->length);
+		item_name   = le32_to_cpu(item_info->name);
+
+		if (item_name == TOC0_ITEM_INFO_NAME_FIRMWARE)
+			load_addr = le32_to_cpu(item_info->load_addr);
+
+		printf(" %08x:%08x %s\n",
+		       item_offset, item_length,
+		       toc0_item_name(item_name));
+	}
+
+	if (num_items && item_offset + item_length < main_length) {
+		item_offset = item_offset + item_length;
+		item_length = main_length - item_offset;
+
+		printf(" %08x:%08x Padding\n",
+		       item_offset, item_length);
+	}
+
+	if (load_addr != -1)
+		printf("Load address: 0x%08x\n", load_addr);
+}
+
+static void toc0_set_header(void *buf, struct stat *sbuf, int ifd,
+			    struct image_tool_params *params)
+{
+	uint32_t key_item_len = 0;
+	uint8_t *key_item = NULL;
+	int ret = EXIT_FAILURE;
+	RSA *root_key = NULL;
+	RSA *fw_key = NULL;
+	FILE *fp;
+
+	/* Either a key item or the root private key is required. */
+	fp = fopen(key_item_file, "rb");
+	if (fp) {
+		pr_info("Creating image using existing key item\n");
+		key_item_len = sizeof(struct toc0_key_item);
+		key_item = OPENSSL_malloc(key_item_len);
+		if (!key_item || fread(key_item, key_item_len, 1, fp) != 1) {
+			pr_err("Failed to read key item from '%s'\n",
+			       root_key_file);
+			goto err;
+		}
+		fclose(fp);
+		fp = NULL;
+	}
+
+	fp = fopen(root_key_file, "rb");
+	if (fp) {
+		root_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+		if (!root_key)
+			root_key = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL);
+		fclose(fp);
+		fp = NULL;
+	}
+
+	/* When using an existing key item, the root key is optional. */
+	if (!key_item && (!root_key || !RSA_get0_d(root_key))) {
+		pr_err("Failed to read private key from '%s'\n",
+		       root_key_file);
+		pr_info("Try 'openssl genrsa -out root_key.pem'\n");
+		goto err;
+	}
+
+	/* The certificate/firmware private key is always required. */
+	fp = fopen(fw_key_file, "rb");
+	if (fp) {
+		fw_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+		fclose(fp);
+		fp = NULL;
+	}
+	if (!fw_key) {
+		/* If the root key is a private key, it can be used instead. */
+		if (root_key && RSA_get0_d(root_key)) {
+			pr_info("Using root key as firmware key\n");
+			fw_key = root_key;
+		} else {
+			pr_err("Failed to read private key from '%s'\n",
+			       fw_key_file);
+			goto err;
+		}
+	}
+
+	/* Warn about potential compatibility issues. */
+	if (key_item || fw_key != root_key)
+		pr_warn("Only H6 supports separate root and firmware keys\n");
+
+	ret = toc0_create(buf, params->file_size, root_key, fw_key,
+			  key_item, key_item_len,
+			  buf + TOC0_DEFAULT_HEADER_LEN,
+			  params->orig_file_size, params->addr);
+
+err:
+	OPENSSL_free(key_item);
+	OPENSSL_free(root_key);
+	if (fw_key != root_key)
+		OPENSSL_free(fw_key);
+	if (fp)
+		fclose(fp);
+
+	if (ret != EXIT_SUCCESS)
+		exit(ret);
+}
+
+static int toc0_check_image_type(uint8_t type)
+{
+	return type == IH_TYPE_SUNXI_TOC0 ? 0 : 1;
+}
+
+static int toc0_vrec_header(struct image_tool_params *params,
+			    struct image_type_params *tparams)
+{
+	tparams->hdr = calloc(tparams->header_size, 1);
+
+	/* Save off the unpadded data size for SHA256 calculation. */
+	params->orig_file_size = params->file_size - TOC0_DEFAULT_HEADER_LEN;
+
+	/* Return padding to 8K blocks. */
+	return ALIGN(params->file_size, PAD_SIZE) - params->file_size;
+}
+
+U_BOOT_IMAGE_TYPE(
+	sunxi_toc0,
+	"Allwinner TOC0 Boot Image support",
+	TOC0_DEFAULT_HEADER_LEN,
+	NULL,
+	toc0_check_params,
+	toc0_verify_header,
+	toc0_print_header,
+	toc0_set_header,
+	NULL,
+	toc0_check_image_type,
+	NULL,
+	toc0_vrec_header
+);
