/**
 *  Microsoft UF2
 *
 * The MIT License (MIT)
 *
 * Copyright (c) Microsoft Corporation
 *
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Copyright (c) 2022 HPMicro
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 */

#ifndef UF2FORMAT_H
#define UF2FORMAT_H

#include <stdint.h>
#include <stdbool.h>

#include "board_api.h"

/*--------------------------------------------------------------------+ */
/* UF2 Configuration */
/*--------------------------------------------------------------------+ */

/* Version is passed by makefile */
#define UF2_VERSION         "0.9.0"

/* The largest flash size that is supported by the board, in bytes, default is 4MB */
/* Flash size is constrained by RAM, a 4MB size requires 2kB RAM, see MAX_BLOCKS */
/* Largest tested is 256MB, with 0x300000 blocks (1.5GB), 64 sectors per cluster */
#ifndef CFG_UF2_FLASH_SIZE
#define CFG_UF2_FLASH_SIZE          (4*1024*1024)
#endif

/* Number of 512-byte blocks in the exposed filesystem, default is just under 32MB */
/* The filesystem needs space for the current file, text files, uploaded file, and FAT */
#ifndef CFG_UF2_NUM_BLOCKS
#define CFG_UF2_NUM_BLOCKS          (0x10109)
#endif

/* Sectors per FAT cluster, must be increased proportionally for larger filesystems */
#ifndef CFG_UF2_SECTORS_PER_CLUSTER
#define CFG_UF2_SECTORS_PER_CLUSTER (1)
#endif

/*--------------------------------------------------------------------+ */
/* */
/*--------------------------------------------------------------------+ */

/* All entries are little endian. */
#define UF2_MAGIC_START0    0x0A324655UL /* "UF2\n" */
#define UF2_MAGIC_START1    0x9E5D5157UL /* Randomly selected */
#define UF2_MAGIC_END       0x0AB16F30UL /* Ditto */

/* If set, the block is "comment" and should not be flashed to the device */
#define UF2_FLAG_NOFLASH    0x00000000
#define UF2_FLAG_FAMILYID   0x00002000

#define MAX_BLOCKS (CFG_UF2_FLASH_SIZE / 256 + 100)
typedef struct {
    uint32_t numBlocks;
    uint32_t numWritten;

    bool aborted;             /* aborting update and reset */

    uint8_t writtenMask[MAX_BLOCKS / 8 + 1];
} WriteState;

typedef struct {
    /* 32 byte header */
    uint32_t magicStart0;
    uint32_t magicStart1;
    uint32_t flags;
    uint32_t targetAddr;
    uint32_t payloadSize;
    uint32_t blockNo;
    uint32_t numBlocks;
    uint32_t familyID;

    /* raw data; */
    uint8_t data[476];

    /* store magic also at the end to limit damage from partial block reads */
    uint32_t magicEnd;
} UF2_Block;


void uf2_init(void);
void uf2_read_block(uint32_t block_no, uint8_t *data);
int  uf2_write_block(uint32_t block_no, uint8_t *data, WriteState *state);

#endif