boot_api.h

/*
 * Copyright (c) 2017-2018, STMicroelectronics - All Rights Reserved
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef BOOT_API_H
#define BOOT_API_H

#include <stdint.h>
#include <stdio.h>

/*
 * Possible value of boot context field 'boot_interface_sel'
 */

/* Value of field 'boot_interface_sel' when no boot occurred */
#define BOOT_API_CTX_BOOT_INTERFACE_SEL_NO			0x0U

/* Boot occurred on SD */
#define BOOT_API_CTX_BOOT_INTERFACE_SEL_FLASH_SD		0x1U

/* Boot occurred on EMMC */
#define BOOT_API_CTX_BOOT_INTERFACE_SEL_FLASH_EMMC		0x2U

/**
 * @brief  Possible value of boot context field 'EmmcXferStatus'
 */
/*
 * Possible value of boot context field 'emmc_xfer_status'
 */
#define BOOT_API_CTX_EMMC_XFER_STATUS_NOT_STARTED			0x0U
#define BOOT_API_CTX_EMMC_XFER_STATUS_DATAEND_DETECTED			0x1U
#define BOOT_API_CTX_EMMC_XFER_STATUS_XFER_OVERALL_TIMEOUT_DETECTED	0x2U
#define BOOT_API_CTX_EMMC_XFER_STATUS_XFER_DATA_TIMEOUT			0x3U

/*
 * Possible value of boot context field 'emmc_error_status'
 */
#define BOOT_API_CTX_EMMC_ERROR_STATUS_NONE                     0x0U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_CMD_TIMEOUT              0x1U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_ACK_TIMEOUT              0x2U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_DATA_CRC_FAIL            0x3U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_NOT_ENOUGH_BOOT_DATA_RX  0x4U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_HEADER_NOT_FOUND         0x5U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_HEADER_SIZE_ZERO         0x6U
#define BOOT_API_CTX_EMMC_ERROR_STATUS_IMAGE_NOT_COMPLETE       0x7U

/* Image Header related definitions */

/* Definition of header version */
#define BOOT_API_HEADER_VERSION					0x00010000U

/*
 * Magic number used to detect header in memory
 * Its value must be 'S' 'T' 'M' 0x32, i.e 0x324D5453 as field
 * 'bootapi_image_header_t.magic'
 * This identifies the start of a boot image.
 */
#define BOOT_API_IMAGE_HEADER_MAGIC_NB				0x324D5453U

/* Definitions related to Authentication used in image header structure */
#define BOOT_API_ECDSA_PUB_KEY_LEN_IN_BYTES			64
#define BOOT_API_ECDSA_SIGNATURE_LEN_IN_BYTES			64
#define BOOT_API_SHA256_DIGEST_SIZE_IN_BYTES			32

/* Possible values of the field 'boot_api_image_header_t.ecc_algo_type' */
#define BOOT_API_ECDSA_ALGO_TYPE_P256NIST			1
#define BOOT_API_ECDSA_ALGO_TYPE_BRAINPOOL256			2

/*
 * Cores secure magic numbers
 * Constant to be stored in bakcup register
 * BOOT_API_MAGIC_NUMBER_TAMP_BCK_REG_IDX
 */
#define BOOT_API_A7_CORE0_MAGIC_NUMBER				0xCA7FACE0U
#define BOOT_API_A7_CORE1_MAGIC_NUMBER				0xCA7FACE1U

/*
 * TAMP_BCK4R register index
 * This register is used to write a Magic Number in order to restart
 * Cortex A7 Core 1 and make it execute @ branch address from TAMP_BCK5R
 */
#define BOOT_API_CORE1_MAGIC_NUMBER_TAMP_BCK_REG_IDX		4U

/*
 * TAMP_BCK5R register index
 * This register is used to contain the branch address of
 * Cortex A7 Core 1 when restarted by a TAMP_BCK4R magic number writing
 */
#define BOOT_API_CORE1_BRANCH_ADDRESS_TAMP_BCK_REG_IDX		5U

/*
 * Possible value of boot context field 'hse_clock_value_in_hz'
 */
#define BOOT_API_CTX_HSE_CLOCK_VALUE_UNDEFINED			0U
#define BOOT_API_CTX_HSE_CLOCK_VALUE_24_MHZ			24000000U
#define BOOT_API_CTX_HSE_CLOCK_VALUE_25_MHZ			25000000U
#define BOOT_API_CTX_HSE_CLOCK_VALUE_26_MHZ			26000000U

/*
 * Possible value of boot context field 'boot_partition_used_toboot'
 */
#define BOOT_API_CTX_BOOT_PARTITION_UNDEFINED			0U

/* Used FSBL1 to boot */
#define BOOT_API_CTX_BOOT_PARTITION_FSBL1			1U

/* Used FSBL2 to boot */
#define BOOT_API_CTX_BOOT_PARTITION_FSBL2			2U

/* OTP_CFG0 */
#define BOOT_API_OTP_MODE_WORD_NB				0
/* Closed = OTP_CFG0[6] */
#define BOOT_API_OTP_MODE_CLOSED_BIT_POS			6

/*
 * Boot Context related definitions
 */

/*
 * Boot core boot configuration structure
 * Specifies all items of the cold boot configuration
 * Memory and peripheral part.
 */
typedef struct {
	/*
	 * Boot interface used to boot : take values from defines
	 * BOOT_API_CTX_BOOT_INTERFACE_SEL_XXX above
	 */
	uint16_t boot_interface_selected;
	uint16_t boot_interface_instance;
	uint32_t reserved1[13];
	uint32_t otp_afmux_values[3];
	uint32_t reserved[9];
	/*
	 * Information specific to an SD boot
	 * Updated each time an SD boot is at least attempted,
	 * even if not successful
	 * Note : This is useful to understand why an SD boot failed
	 * in particular
	 */
	uint32_t sd_err_internal_timeout_cnt;
	uint32_t sd_err_dcrc_fail_cnt;
	uint32_t sd_err_dtimeout_cnt;
	uint32_t sd_err_ctimeout_cnt;
	uint32_t sd_err_ccrc_fail_cnt;
	uint32_t sd_overall_retry_cnt;
	/*
	 * Information specific to an eMMC boot
	 * Updated each time an eMMC boot is at least attempted,
	 * even if not successful
	 * Note : This is useful to understand why an eMMC boot failed
	 * in particular
	 */
	uint32_t emmc_xfer_status;
	uint32_t emmc_error_status;
	uint32_t emmc_nbbytes_rxcopied_tosysram_download_area;
	uint32_t hse_clock_value_in_hz;
	/*
	 * Boot partition :
	 * ie FSBL partition on which the boot was successful
	 */
	uint32_t boot_partition_used_toboot;

} __packed boot_api_context_t;

/*
 * Image Header related definitions
 */

/*
 * Structure used to define the common Header format used for FSBL, xloader,
 * ... and in particular used by bootROM for FSBL header readout.
 * FSBL header size is 256 Bytes = 0x100
 */
typedef struct {
	/* BOOT_API_IMAGE_HEADER_MAGIC_NB */
	uint32_t magic;
	uint8_t image_signature[BOOT_API_ECDSA_SIGNATURE_LEN_IN_BYTES];
	/*
	 * Checksum of payload
	 * 32-bit sum all all payload bytes considered as 8 bit unigned numbers,
	 * discarding any overflow bits.
	 * Use to check UART/USB downloaded image integrity when signature
	 * is not used (i.e bit 0 : 'No_sig_check' = 1 in option flags)
	 */
	uint32_t payload_checksum;
	/* Image header version : should have value BOOT_API_HEADER_VERSION */
	uint32_t header_version;
	/* Image length in bytes */
	uint32_t image_length;
	/*
	 * Image Entry point address : should be in the SYSRAM area
	 * and at least within the download area range
	 */
	uint32_t image_entry_point;
	/* Reserved */
	uint32_t reserved1;
	/*
	 * Image load address : not used by bootROM but to be consistent
	 * with header format for other packages (xloader, ...)
	 */
	uint32_t load_address;
	/* Reserved */
	uint32_t reserved2;
	/* Image version to be compared by bootROM with monotonic
	 * counter value in OTP_CFG4 prior executing the downloaded image
	 */
	uint32_t image_version;
	/*
	 * Option flags:
	 * Bit 0 : No signature check request : 'No_sig_check'
	 *      value 1 : for No signature check request
	 *      value 0 : No request to bypass the signature check
	 * Note : No signature check is never allowed on a Secured chip
	 */
	uint32_t option_flags;
	/*
	 * Type of ECC algorithm to use  :
	 * value 1 : for P-256 NIST algorithm
	 * value 2 : for Brainpool 256 algorithm
	 * See definitions 'BOOT_API_ECDSA_ALGO_TYPE_XXX' above.
	 */
	uint32_t ecc_algo_type;
	/*
	 * OEM ECC Public Key (aka Root pubk) provided in header on 512 bits.
	 * The SHA-256 hash of the OEM ECC pubk must match the one stored
	 * in OTP cells.
	 */
	uint8_t ecc_pubk[BOOT_API_ECDSA_PUB_KEY_LEN_IN_BYTES];
	/* Pad up to 256 byte total size */
	uint8_t pad[83];
	/* Add binary type information */
	uint8_t binary_type;
} __packed boot_api_image_header_t;

#endif /* BOOT_API_H */