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29 * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
35 * \author Francesco Sacchi <batt@develer.com>
37 * \brief BattFS: a filesystem for embedded platforms (interface).
38 * TODO: Add detailed filesystem description.
44 #include <cfg/compiler.h> // uintXX_t; STATIC_ASSERT
45 #include <algos/rotating_hash.h>
47 typedef uint16_t filled_t;
48 typedef uint16_t page_off_t;
49 typedef uint8_t inode_t;
50 typedef uint8_t seqnum_t;
51 typedef rotating_t battfs_crc_t;
53 typedef uint16_t battfs_page_t;
57 * \note fields order is chosen to comply
60 typedef struct BattFsPageHeader
62 inode_t inode; ///< File inode (file identifier).
63 seqnum_t seqnum; ///< bit[1:0]: Page sequence number; bit[7:2] unused for now, must be set to 1.
64 filled_t filled; ///< Filled bytes in page.
65 page_off_t page_off; ///< Page offset inside file.
66 battfs_crc_t crc; ///< CRC of the page header.
69 /* Ensure structure has no padding added */
70 STATIC_ASSERT(sizeof(BattFsPageHeader) == sizeof(filled_t) + sizeof(page_off_t)
71 + sizeof(inode_t) + sizeof(seqnum_t) + siezof(BattFsDisk));
74 * Reset page sequence number of struct \a m to default value (0xFF).
76 #define RESET_SEQ(m) ((m).seqnum = 0xFF)
79 * Get page sequence number from struct \a m.
81 #define SEQ(m) ((m).seqnum & 0x03)
84 * Set sequence number of struct \a m to \a d.
86 #define SET_SEQ(m, d) ((m).seqnum = ((m).seqnum & 0xFC) | ((d) & 0x03))
89 * Increment sequence number of struct \a m.
91 #define INC_SEQ(m) SET_SEQ((m), SEQ(m) + 1)
97 * Type interface for disk init function.
98 * \return true if all is ok, false otherwise.
100 typedef bool (*disk_init_t) (struct BattFsDisk *d);
103 * Type interface for disk page read function.
104 * \a page is the page address, \a size the lenght to be read.
105 * \return the number of bytes read.
107 typedef size_t (*disk_page_read_t) (struct BattFsDisk *d, void *buf, battfs_page_t page, size_t size);
110 * Type interface for disk page write function.
111 * \a page is the page address, \a size the lenght to be written.
112 * \return the number of bytes written.
114 typedef size_t (*disk_page_write_t) (struct BattFsDisk *d, const void *buf, battfs_page_t page, size_t size);
117 * Type interface for disk page erase function.
118 * \a page is the page address.
119 * \return true if all is ok, false otherwise.
121 typedef bool (*disk_page_erase_t) (struct BattFsDisk *d, battfs_page_t page);
123 typedef uint32_t disk_size_t ///< Type for disk sizes.
126 * Context used to describe a disk.
127 * This context structure will be used to access disk.
128 * Must be initialized by hw memory driver.
130 typedef struct BattFsDisk
132 disk_init_t init; ///< Disk init.
133 disk_page_read_t read; ///< Page read.
134 disk_page_write_t write; ///< Page write.
135 disk_page_erase_t erase; ///< Page erase.
137 disk_size_t disk_size; ///< Size of the disk, in bytes.
138 disk_size_t free_space; ///< Free space on the disk, in bytes.
139 /* TODO add other fields. */
142 #endif /* FS_BATTFS_H */