text: /* 
   * Copyright (c) 2015 Nordic Semiconductor ASA
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   * 
   *   1. Redistributions of source code must retain the above copyright notice, this list 
   *      of conditions and the following disclaimer.
   *
   *   2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA 
   *      integrated circuit in a product or a software update for such product, must reproduce 
   *      the above copyright notice, this list of conditions and the following disclaimer in 
   *      the documentation and/or other materials provided with the distribution.
   *
   *   3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be 
   *      used to endorse or promote products derived from this software without specific prior 
   *      written permission.
   *
   *   4. This software, with or without modification, must only be used with a 
   *      Nordic Semiconductor ASA integrated circuit.
   *
   *   5. Any software provided in binary or object form under this license must not be reverse 
   *      engineered, decompiled, modified and/or disassembled. 
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   * 
   */
  
  
  #ifndef FDS_INTERNAL_DEFS_H__
  #define FDS_INTERNAL_DEFS_H__
  
  #include <stdint.h>
  #include <stdbool.h>
  #include "fds_config.h"
  
  #if defined (FDS_THREADS)
      #include "nrf_soc.h"
      #include "app_util_platform.h"
  #endif
  
  #define FDS_PAGE_TAG_SIZE       (2) // Page tag size, in 4-byte words.
  #define FDS_PAGE_TAG_WORD_0     (0) // Offset of the first word in the page tag from the page address.
  #define FDS_PAGE_TAG_WORD_1     (1) // Offset of the second word in the page tag from the page address.
  
  // Page tag constants
  #define FDS_PAGE_TAG_MAGIC      (0xDEADC0DE)
  #define FDS_PAGE_TAG_SWAP       (0xF11E01FF)
  #define FDS_PAGE_TAG_DATA       (0xF11E01FE)
  
  #define FDS_ERASED_WORD         (0xFFFFFFFF)
  
  #define FDS_OFFSET_TL           (0) // Offset of TL from the record base address, in 4-byte words.
  #define FDS_OFFSET_IC           (1) // Offset of IC from the record base address, in 4-byte words.
  #define FDS_OFFSET_ID           (2) // Offset of ID from the record base address, in 4-byte words.
  #define FDS_OFFSET_DATA         (3) // Offset of the data (chunks) from the record base address, in 4-byte words.
  
  #define FDS_HEADER_SIZE_TL      (1) // Size of the TL part of the header, in 4-byte words.
  #define FDS_HEADER_SIZE_IC      (1) // Size of the IC part of the header, in 4-byte words.
  #define FDS_HEADER_SIZE_ID      (1) // Size of the record ID in the header, in 4-byte words.
  #define FDS_HEADER_SIZE         (3) // Size of the whole header, in 4-byte words.
  
  #define FDS_OP_EXECUTING        (FS_SUCCESS)
  #define FDS_OP_COMPLETED        (0x1D1D)
  
  // The size of a physical page, in 4-byte words.
  #if   defined(NRF51)
      #define FDS_PHY_PAGE_SIZE   (256)
  #elif defined(NRF52)
      #define FDS_PHY_PAGE_SIZE   (1024)
  #endif
  
  // The number of physical pages to be used. This value is configured indirectly.
  #define FDS_PHY_PAGES               ((FDS_VIRTUAL_PAGES * FDS_VIRTUAL_PAGE_SIZE) / FDS_PHY_PAGE_SIZE)
  
  // The size of a virtual page, in number of physical pages.
  #define FDS_PHY_PAGES_IN_VPAGE      (FDS_VIRTUAL_PAGE_SIZE / FDS_PHY_PAGE_SIZE)
  
  // The number of pages available to store data; which is the total minus one (the swap).
  #define FDS_MAX_PAGES               (FDS_VIRTUAL_PAGES - 1)
  
   // Just a shorter name for the size, in words, of a virtual page.
  #define FDS_PAGE_SIZE               (FDS_VIRTUAL_PAGE_SIZE)
  
  
  #if (FDS_VIRTUAL_PAGE_SIZE % FDS_PHY_PAGE_SIZE != 0)
      #error "FDS_VIRTUAL_PAGE_SIZE must be a multiple of the size of a physical page."
  #endif
  
  #if (FDS_VIRTUAL_PAGES < 2)
      #error "FDS requires at least two virtual pages."
  #endif
  
  
  // FDS internal status flags.
  typedef enum
  {
      FDS_FLAG_INITIALIZING   = (1 << 0),  // The module is initializing.
      FDS_FLAG_INITIALIZED    = (1 << 1),  // The module is initialized.
      FDS_FLAG_PROCESSING     = (1 << 2),  // The queue is being processed.
      FDS_FLAG_VERIFY_CRC     = (1 << 3),  // Verify CRC upon writing a record.
  } fds_flags_t;
  
  
  // Page types.
  typedef enum
  {
      FDS_PAGE_DATA,      // Page is ready for storage.
      FDS_PAGE_SWAP,      // Page is reserved for garbage collection.
      FDS_PAGE_ERASED,    // Page is erased.
      FDS_PAGE_UNDEFINED, // Undefined page type.
  } fds_page_type_t;
  
  
  typedef struct
  {
      fds_page_type_t         page_type;      // The page type.
      uint32_t        const * p_addr;         // The address of the page.
      uint16_t                write_offset;   // The page write offset, in 4-byte words.
      uint16_t                words_reserved; // The amount of words reserved by fds_write_reserve().
      uint16_t                records_open;   // The number of records opened using fds_open().
      bool                    can_gc;         // Indicates that there are some records that have been deleted.
  } fds_page_t;
  
  
  typedef struct
  {
      uint32_t const * p_addr;
      uint16_t         write_offset;
  } fds_swap_page_t;
  
  
  // FDS op-codes.
  typedef enum
  {
      FDS_OP_NONE,
      FDS_OP_INIT,        // Initialize the module.
      FDS_OP_WRITE,       // Write a record to flash.
      FDS_OP_UPDATE,      // Update a record.
      FDS_OP_DEL_RECORD,  // Delete a record.
      FDS_OP_DEL_FILE,    // Delete a file.
      FDS_OP_GC           // Run garbage collection.
  } fds_op_code_t;
  
  
  typedef enum
  {
      FDS_OP_INIT_TAG_SWAP,
      FDS_OP_INIT_TAG_DATA,
      FDS_OP_INIT_ERASE_SWAP,
      FDS_OP_INIT_PROMOTE_SWAP,
  } fds_init_step_t;
  
  
  typedef enum
  {
      FDS_OP_WRITE_HEADER_BEGIN,      // Write the record key and length.
      FDS_OP_WRITE_HEADER_FINALIZE,   // Write the file ID and CRC.
      FDS_OP_WRITE_RECORD_ID,         // Write the record ID.
      FDS_OP_WRITE_CHUNKS,            // Write the record data.
      FDS_OP_WRITE_FIND_RECORD,
      FDS_OP_WRITE_FLAG_DIRTY,        // Flag a record as dirty (as part of an update operation).
      FDS_OP_WRITE_DONE,
  } fds_write_step_t;
  
  
  typedef enum
  {
      FDS_OP_DEL_RECORD_FLAG_DIRTY,   // Flag a record as dirty.
      FDS_OP_DEL_FILE_FLAG_DIRTY,     // Flag multiple records as dirty.
      FDS_OP_DEL_DONE,
  } fds_delete_step_t;
  
  
  #if defined(__CC_ARM)
      #pragma push
      #pragma anon_unions
  #elif defined(__ICCARM__)
      #pragma language=extended
  #elif defined(__GNUC__)
      // anonymous unions are enabled by default
  #endif
  
  typedef struct
  {
      fds_op_code_t op_code;                      // The opcode for the operation.
      union
      {
          struct
          {
              fds_init_step_t step;               // The current step the operation is at.
          } init;
          struct
          {
              fds_header_t     header;
              fds_write_step_t step;              // The current step the operation is at.
              uint16_t         page;              // The page the flash space for this command was reserved.
              uint16_t         chunk_offset;      // Offset used for writing record chunks, in 4-byte words.
              uint8_t          chunk_count;       // Number of chunks to be written.
              uint32_t         record_to_delete;  // The record to delete in case this is an update.
          } write;
          struct
          {
              fds_delete_step_t step;
              uint16_t          file_id;
              uint16_t          record_key;
              uint32_t          record_to_delete;
          } del;
      };
  } fds_op_t;
  
  #if defined(__CC_ARM)
      #pragma pop
  #elif defined(__ICCARM__)
      // leave anonymous unions enabled
  #elif defined(__GNUC__)
      // anonymous unions are enabled by default
  #endif
  
  
  typedef struct
  {
      fds_op_t op[FDS_OP_QUEUE_SIZE];    // Queued flash operations.
      uint32_t rp;                       // The index of the command being executed.
      uint32_t count;                    // Number of elements in the queue.
  } fds_op_queue_t;
  
  
  typedef struct
  {
      fds_record_chunk_t chunk[FDS_CHUNK_QUEUE_SIZE];
      uint32_t           rp;
      uint32_t           count;
  } fds_chunk_queue_t;
  
  
  enum
  {
      PAGE_ERASED = 0x1,
      PAGE_DATA   = 0x2,
      SWAP_EMPTY  = 0x4,
      SWAP_DIRTY  = 0x8,
  };
  
  
  typedef enum
  {
      // This is a fatal error.
      NO_PAGES,
  
      // All pages are erased. Perform a fresh installation.
      FRESH_INSTALL     = (PAGE_ERASED),
  
      // Swap is missing. Tag an erased page as swap.
      TAG_SWAP          = (PAGE_ERASED | PAGE_DATA),
  
      // Swap is empty. Tag all erased pages as data.
      TAG_DATA         = (PAGE_ERASED | SWAP_EMPTY),
  
      // Swap is empty. Tag all remaining erased pages as data.
      TAG_DATA_INST    = (PAGE_ERASED | PAGE_DATA | SWAP_EMPTY),
  
      // The swap is dirty. This indicates that the device powered off during GC. However, since there
      // is also an erased page, it is possible to assume that that page had been entirely garbage
      // collected. Hence, tag the swap as data, one erased page as swap and any remaining pages as data.
      PROMOTE_SWAP      = (PAGE_ERASED | SWAP_DIRTY),
  
      // Similar to the above. Tag the swap as data, one erased page as swap, and any remain
      // pages as data.
      PROMOTE_SWAP_INST = (PAGE_ERASED | PAGE_DATA | SWAP_DIRTY),
  
      // The swap is dirty (written) and there are no erased pages. This indicates that the device
      // was powered off during GC. It is safe to discard (erase) the swap, since data that was
      // swapped out lies in one of the valid pages.
      DISCARD_SWAP      = (PAGE_DATA  | SWAP_DIRTY),
  
      // Do nothing.
      ALREADY_INSTALLED = (PAGE_DATA  | SWAP_EMPTY),
  
  } fds_init_opts_t;
  
  
  typedef enum
  {
      GC_BEGIN,               // Begin GC.
      GC_NEXT_PAGE,           // GC a page.
      GC_FIND_NEXT_RECORD,    // Find a valid record to copy.
      GC_COPY_RECORD,         // Copy a valid record to swap.
      GC_ERASE_PAGE,          // Erase the page being garbage collected.
      GC_DISCARD_SWAP,        // Erase (discard) the swap page.
      GC_PROMOTE_SWAP,        // Tag the swap as valid.
      GC_TAG_NEW_SWAP         // Tag a freshly erased (GCed) page as swap.
  } fds_gc_state_t;
  
  
  // Holds garbage collection status and related data.
  typedef struct
  {
      fds_gc_state_t   state;                     // The current GC step.
      uint16_t         cur_page;                  // The current page being garbage collected.
      uint32_t const * p_record_src;              // The current record being copied to swap.
      uint16_t         run_count;                 // Total number of times GC was run.
      bool             do_gc_page[FDS_MAX_PAGES]; // Controls which pages to garbage collect.
      bool             resume;                    // Whether or not GC should be resumed.
  } fds_gc_data_t;
  
  
  // Macros to enable and disable application interrupts.
  #if defined (FDS_THREADS)
  
      #define CRITICAL_SECTION_ENTER()    CRITICAL_REGION_ENTER()
      #define CRITICAL_SECTION_EXIT()     CRITICAL_REGION_EXIT()
  
  #else
  
      #define CRITICAL_SECTION_ENTER()
      #define CRITICAL_SECTION_EXIT()
  
  #endif
  
  
  #endif // FDS_INTERNAL_DEFS_H__
  