/*
   * (C) Copyright 2015 Google,  Inc
   * Written by Simon Glass <sjg@chromium.org>
   *

   * (C) 2017 Theobroma Systems Design und Consulting GmbH
   *

   * SPDX-License-Identifier:	GPL-2.0+
   *
   * Helper functions for Rockchip images
   */
  
  #include "imagetool.h"
  #include <image.h>
  #include <rc4.h>
  #include "mkimage.h"
  #include "rkcommon.h"

  #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))

  enum {
  	RK_SIGNATURE		= 0x0ff0aa55,
  };
  
  /**
   * struct header0_info - header block for boot ROM
   *
   * This is stored at SD card block 64 (where each block is 512 bytes, or at
   * the start of SPI flash. It is encoded with RC4.
   *
   * @signature:		Signature (must be RKSD_SIGNATURE)
   * @disable_rc4:	0 to use rc4 for boot image,  1 to use plain binary

   * @init_offset:	Offset in blocks of the SPL code from this header

   *			block. E.g. 4 means 2KB after the start of this header.
   * Other fields are not used by U-Boot
   */
  struct header0_info {
  	uint32_t signature;
  	uint8_t reserved[4];
  	uint32_t disable_rc4;

  	uint16_t init_offset;
  	uint8_t reserved1[492];
  	uint16_t init_size;
  	uint16_t init_boot_size;

  	uint8_t reserved2[2];
  };

  /**

   * struct header1_info
   */
  struct header1_info {
  	uint32_t magic;

  };
  
  /**

   * struct spl_info - spl info for each chip
   *
   * @imagename:		Image name(passed by "mkimage -n")
   * @spl_hdr:		Boot ROM requires a 4-bytes spl header
   * @spl_size:		Spl size(include extra 4-bytes spl header)

   * @spl_rc4:		RC4 encode the SPL binary (same key as header)

   */

  struct spl_info {
  	const char *imagename;
  	const char *spl_hdr;
  	const uint32_t spl_size;

  	const bool spl_rc4;

  };
  
  static struct spl_info spl_infos[] = {

  	{ "rk3036", "RK30", 0x1000, false },
  	{ "rk3128", "RK31", 0x1800, false },
  	{ "rk3188", "RK31", 0x8000 - 0x800, true },
  	{ "rk322x", "RK32", 0x8000 - 0x1000, false },
  	{ "rk3288", "RK32", 0x8000, false },
  	{ "rk3328", "RK32", 0x8000 - 0x1000, false },
  	{ "rk3368", "RK33", 0x8000 - 0x1000, false },
  	{ "rk3399", "RK33", 0x30000 - 0x2000, false },
  	{ "rv1108", "RK11", 0x1800, false },

  };

  static unsigned char rc4_key[16] = {
  	124, 78, 3, 4, 85, 5, 9, 7,
  	45, 44, 123, 56, 23, 13, 23, 17
  };

  static struct spl_info *rkcommon_get_spl_info(char *imagename)
  {
  	int i;

  	if (!imagename)
  		return NULL;

  	for (i = 0; i < ARRAY_SIZE(spl_infos); i++)
  		if (!strncmp(imagename, spl_infos[i].imagename, 6))
  			return spl_infos + i;
  
  	return NULL;
  }
  
  int rkcommon_check_params(struct image_tool_params *params)
  {
  	int i;
  
  	if (rkcommon_get_spl_info(params->imagename) != NULL)

  		return EXIT_SUCCESS;
  
  	/*
  	 * If this is a operation (list or extract), the don't require
  	 * imagename to be set.
  	 */
  	if (params->lflag || params->iflag)
  		return EXIT_SUCCESS;

  
  	fprintf(stderr, "ERROR: imagename (%s) is not supported!
  ",

  		params->imagename ? params->imagename : "NULL");

  
  	fprintf(stderr, "Available imagename:");
  	for (i = 0; i < ARRAY_SIZE(spl_infos); i++)
  		fprintf(stderr, "\t%s", spl_infos[i].imagename);
  	fprintf(stderr, "
  ");

  	return EXIT_FAILURE;

  }
  
  const char *rkcommon_get_spl_hdr(struct image_tool_params *params)
  {
  	struct spl_info *info = rkcommon_get_spl_info(params->imagename);
  
  	/*
  	 * info would not be NULL, because of we checked params before.
  	 */
  	return info->spl_hdr;
  }

  
  int rkcommon_get_spl_size(struct image_tool_params *params)

  {
  	struct spl_info *info = rkcommon_get_spl_info(params->imagename);
  
  	/*
  	 * info would not be NULL, because of we checked params before.
  	 */

  	return info->spl_size;

  }

  bool rkcommon_need_rc4_spl(struct image_tool_params *params)

  {
  	struct spl_info *info = rkcommon_get_spl_info(params->imagename);
  
  	/*
  	 * info would not be NULL, because of we checked params before.
  	 */

  	return info->spl_rc4;

  }

  static void rkcommon_set_header0(void *buf, uint file_size,
  				 struct image_tool_params *params)

  {

  	struct header0_info *hdr = buf;

  	memset(buf, '\0', RK_INIT_OFFSET * RK_BLK_SIZE);

  	hdr->signature = RK_SIGNATURE;

  	hdr->disable_rc4 = !rkcommon_need_rc4_spl(params);

  	hdr->init_offset = RK_INIT_OFFSET;

  	hdr->init_size = DIV_ROUND_UP(file_size, RK_BLK_SIZE);
  	/*
  	 * The init_size has to be a multiple of 4 blocks (i.e. of 2K)
  	 * or the BootROM will not boot the image.
  	 *
  	 * Note: To verify that this is not a legacy constraint, we
  	 *       rechecked this against the RK3399 BootROM.
  	 */
  	hdr->init_size = ROUND(hdr->init_size, 4);
  	/*

  	 * init_boot_size needs to be set, as it is read by the BootROM
  	 * to determine the size of the next-stage bootloader (e.g. U-Boot
  	 * proper), when used with the back-to-bootrom functionality.
  	 *
  	 * see https://lists.denx.de/pipermail/u-boot/2017-May/293267.html
  	 * for a more detailed explanation by Andy Yan

  	 */

  	hdr->init_boot_size = hdr->init_size + RK_MAX_BOOT_SIZE / RK_BLK_SIZE;

  
  	rc4_encode(buf, RK_BLK_SIZE, rc4_key);

  }
  
  int rkcommon_set_header(void *buf, uint file_size,
  			struct image_tool_params *params)
  {
  	struct header1_info *hdr = buf + RK_SPL_HDR_START;
  
  	if (file_size > rkcommon_get_spl_size(params))
  		return -ENOSPC;
  
  	rkcommon_set_header0(buf, file_size, params);

  	/* Set up the SPL name (i.e. copy spl_hdr over) */

  	memcpy(&hdr->magic, rkcommon_get_spl_hdr(params), RK_SPL_HDR_SIZE);

  	if (rkcommon_need_rc4_spl(params))
  		rkcommon_rc4_encode_spl(buf, RK_SPL_HDR_START,
  					params->file_size - RK_SPL_HDR_START);

  
  	return 0;
  }

  static inline unsigned rkcommon_offset_to_spi(unsigned offset)
  {
  	/*
  	 * While SD/MMC images use a flat addressing, SPI images are padded
  	 * to use the first 2K of every 4K sector only.
  	 */
  	return ((offset & ~0x7ff) << 1) + (offset & 0x7ff);
  }

  static int rkcommon_parse_header(const void *buf, struct header0_info *header0,
  				 struct spl_info **spl_info)
  {
  	unsigned hdr1_offset;
  	struct header1_info *hdr1_sdmmc, *hdr1_spi;
  	int i;
  
  	if (spl_info)
  		*spl_info = NULL;
  
  	/*
  	 * The first header (hdr0) is always RC4 encoded, so try to decrypt
  	 * with the well-known key.
  	 */
  	memcpy((void *)header0, buf, sizeof(struct header0_info));
  	rc4_encode((void *)header0, sizeof(struct header0_info), rc4_key);
  
  	if (header0->signature != RK_SIGNATURE)
  		return -EPROTO;
  
  	/* We don't support RC4 encoded image payloads here, yet... */
  	if (header0->disable_rc4 == 0)
  		return -ENOSYS;
  
  	hdr1_offset = header0->init_offset * RK_BLK_SIZE;
  	hdr1_sdmmc = (struct header1_info *)(buf + hdr1_offset);
  	hdr1_spi = (struct header1_info *)(buf +
  					   rkcommon_offset_to_spi(hdr1_offset));
  
  	for (i = 0; i < ARRAY_SIZE(spl_infos); i++) {
  		if (!memcmp(&hdr1_sdmmc->magic, spl_infos[i].spl_hdr, 4)) {
  			if (spl_info)
  				*spl_info = &spl_infos[i];
  			return IH_TYPE_RKSD;
  		} else if (!memcmp(&hdr1_spi->magic, spl_infos[i].spl_hdr, 4)) {
  			if (spl_info)
  				*spl_info = &spl_infos[i];
  			return IH_TYPE_RKSPI;
  		}
  	}
  
  	return -1;
  }
  
  int rkcommon_verify_header(unsigned char *buf, int size,
  			   struct image_tool_params *params)
  {
  	struct header0_info header0;
  	struct spl_info *img_spl_info, *spl_info;
  	int ret;
  
  	ret = rkcommon_parse_header(buf, &header0, &img_spl_info);
  
  	/* If this is the (unimplemented) RC4 case, then rewrite the result */
  	if (ret == -ENOSYS)
  		return 0;
  
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * If no 'imagename' is specified via the commandline (e.g. if this is
  	 * 'dumpimage -l' w/o any further constraints), we accept any spl_info.
  	 */
  	if (params->imagename == NULL)
  		return 0;
  
  	/* Match the 'imagename' against the 'spl_hdr' found */
  	spl_info = rkcommon_get_spl_info(params->imagename);
  	if (spl_info && img_spl_info)
  		return strcmp(spl_info->spl_hdr, img_spl_info->spl_hdr);
  
  	return -ENOENT;
  }
  
  void rkcommon_print_header(const void *buf)
  {
  	struct header0_info header0;
  	struct spl_info *spl_info;
  	uint8_t image_type;
  	int ret;
  
  	ret = rkcommon_parse_header(buf, &header0, &spl_info);
  
  	/* If this is the (unimplemented) RC4 case, then fail silently */
  	if (ret == -ENOSYS)
  		return;
  
  	if (ret < 0) {
  		fprintf(stderr, "Error: image verification failed
  ");
  		return;
  	}
  
  	image_type = ret;
  
  	printf("Image Type:   Rockchip %s (%s) boot image
  ",
  	       spl_info->spl_hdr,
  	       (image_type == IH_TYPE_RKSD) ? "SD/MMC" : "SPI");
  	printf("Data Size:    %d bytes
  ", header0.init_size * RK_BLK_SIZE);
  }

  void rkcommon_rc4_encode_spl(void *buf, unsigned int offset, unsigned int size)
  {
  	unsigned int remaining = size;
  
  	while (remaining > 0) {
  		int step = (remaining > RK_BLK_SIZE) ? RK_BLK_SIZE : remaining;
  
  		rc4_encode(buf + offset, step, rc4_key);
  		offset += RK_BLK_SIZE;
  		remaining -= step;
  	}
  }

  int rkcommon_vrec_header(struct image_tool_params *params,
  			 struct image_type_params *tparams,
  			 unsigned int alignment)

  {

  	unsigned int  unpadded_size;
  	unsigned int  padded_size;

  	/*
  	 * The SPL image looks as follows:
  	 *
  	 * 0x0    header0 (see rkcommon.c)
  	 * 0x800  spl_name ('RK30', ..., 'RK33')

  	 *        (start of the payload for AArch64 payloads: we expect the
  	 *        first 4 bytes to be available for overwriting with our
  	 *        spl_name)

  	 * 0x804  first instruction to be executed

  	 *        (start of the image/payload for 32bit payloads)

  	 *

  	 * For AArch64 (ARMv8) payloads, natural alignment (8-bytes) is
  	 * required for its sections (so the image we receive needs to
  	 * have the first 4 bytes reserved for the spl_name).  Reserving
  	 * these 4 bytes is done using the BOOT0_HOOK infrastructure.

  	 *

  	 * The header is always at 0x800 (as we now use a payload
  	 * prepadded using the boot0 hook for all targets): the first
  	 * 4 bytes of these images can safely be overwritten using the
  	 * boot magic.

  	 */

  	tparams->header_size = RK_SPL_HDR_START;

  
  	/* Allocate, clear and install the header */
  	tparams->hdr = malloc(tparams->header_size);

  	if (!tparams->hdr)
  		return -ENOMEM;

  	memset(tparams->hdr, 0, tparams->header_size);

  
  	/*
  	 * If someone passed in 0 for the alignment, we'd better handle
  	 * it correctly...
  	 */
  	if (!alignment)
  		alignment = 1;
  
  	unpadded_size = tparams->header_size + params->file_size;
  	padded_size = ROUND(unpadded_size, alignment);
  
  	return padded_size - unpadded_size;

  }