X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=fs%2Fbattfs.h;h=14728a8d2b199f82c36054fa9237bbdb1bc5904a;hb=75aa6c9fd80bb9d4bb3dc3ffb001a266915fe14f;hp=d2e3b6fcccf94d55eddecaca6cb2fc1360105f5e;hpb=79ac7263077c2338064c6324e14d404beb251246;p=bertos.git diff --git a/fs/battfs.h b/fs/battfs.h index d2e3b6fc..14728a8d 100644 --- a/fs/battfs.h +++ b/fs/battfs.h @@ -42,13 +42,16 @@ #define FS_BATTFS_H #include // uintXX_t; STATIC_ASSERT +#include // CPU_BITS_PER_CHAR #include -typedef uint16_t filled_t; +typedef uint16_t fill_t; +typedef fill_t pgaddr_t; typedef uint16_t pgoff_t; +typedef pgoff_t mark_t; typedef uint8_t inode_t; -typedef uint8_t seqnum_t; -typedef rotating_t fsc_t; +typedef uint8_t seq_t; +typedef rotating_t fcs_t; /** * BattFS page header. @@ -57,68 +60,86 @@ typedef rotating_t fsc_t; */ typedef struct BattFsPageHeader { - inode_t inode; ///< File inode (file identifier). - seqnum_t seqnum; ///< bit[1:0]: Page sequence number; bit[7:2] unused for now, must be set to 1. - filled_t filled; ///< Filled bytes in page. - pgoff_t pgoff; ///< Page offset inside file. - fsc_t fsc; ///< CRC of the page header. + inode_t inode; ///< File inode (file identifier). + seq_t seq; ///< Page sequence number. + mark_t mark; ///< Marker used to keep trace of free/used pages. + pgoff_t pgoff; ///< Page offset inside file. + fill_t fill; ///< Filled bytes in page. + uint16_t rfu; ///< Reserved for future use, 0xFFFF for now. + + /** + * FCS (Frame Check Sequence) of the page header. + * \note This field must be the last one! + * This is needed because if the page is only partially + * written, we can use this to detect it. + */ + fcs_t fcs; } BattFsPageHeader; - /* Ensure structure has no padding added */ -STATIC_ASSERT(sizeof(BattFsPageHeader) == sizeof(filled_t) + sizeof(pgoff_t) - + sizeof(inode_t) + sizeof(seqnum_t) + sizeof(fsc_t)); +STATIC_ASSERT(sizeof(BattFsPageHeader) == 12); + /** - * Reset page sequence number of struct \a m to default value (0xFF). + * Mark for valid pages. + * Simply set to 1 all field bits. */ -#define RESET_SEQ(m) ((m).seqnum = 0xFF) +#define MARK_PAGE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(mark_t))) - 1) /** - * Get page sequence number from struct \a m. + * Max number of files. */ -#define SEQ(m) ((m).seqnum & 0x03) +#define BATTFS_MAX_FILES (1 << (CPU_BITS_PER_CHAR * sizeof(inode_t))) + +/* Fwd decl */ +struct BattFsSuper; /** - * Set sequence number of struct \a m to \a d. + * Type for disk page addressing. */ -#define SET_SEQ(m, d) ((m).seqnum = ((m).seqnum & 0xFC) | ((d) & 0x03)) +typedef uint16_t pgcnt_t; /** - * Increment sequence number of struct \a m. + * Sentinel used to keep trace of unset pages in disk->pag_array. */ -#define INC_SEQ(m) SET_SEQ((m), SEQ(m) + 1) - -/* Fwd decl */ -struct BattFsSuper; +#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1) /** * Type interface for disk init function. * \return true if all is ok, false otherwise. */ -typedef bool (*disk_init_t) (struct BattFsSuper *d); +typedef bool (*disk_open_t) (struct BattFsSuper *d); /** * Type interface for disk page read function. - * \a page is the page address, \a size the lenght to be read. + * \a page is the page address, \a addr the address inside the page, + * \a size the lenght to be read. * \return the number of bytes read. */ -typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, void *buf, battfs_page_t page, size_t size); +typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t); /** * Type interface for disk page write function. - * \a page is the page address, \a size the lenght to be written. + * \a page is the page address, \a addr the address inside the page, + * \a size the lenght to be written. * \return the number of bytes written. */ -typedef size_t (*disk_page_write_t) (struct BattFsSuper *d, const void *buf, battfs_page_t page, size_t size); +typedef size_t (*disk_page_write_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t); /** * Type interface for disk page erase function. * \a page is the page address. * \return true if all is ok, false otherwise. */ -typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, battfs_page_t page); +typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, pgcnt_t page); -typedef uint32_t disk_size_t ///< Type for disk sizes. +/** + * Type interface for disk deinit function. + * \return true if all is ok, false otherwise. + */ +typedef bool (*disk_close_t) (struct BattFsSuper *d); + + +typedef uint32_t disk_size_t; ///< Type for disk sizes. /** * Context used to describe a disk. @@ -127,14 +148,33 @@ typedef uint32_t disk_size_t ///< Type for disk sizes. */ typedef struct BattFsSuper { - disk_init_t init; ///< Disk init. + disk_open_t open; ///< Disk init. disk_page_read_t read; ///< Page read. disk_page_write_t write; ///< Page write. disk_page_erase_t erase; ///< Page erase. + disk_close_t close; ///< Disk deinit. - disk_size_t disk_size; ///< Size of the disk, in bytes. + pgaddr_t page_size; ///< Size of a disk page, in bytes. + pgcnt_t page_count; ///< Number of pages on disk. + + /** + * Page allocation array. + * This array must be allocated somewhere and + * must have enough space for page_count elements. + * Is used by the filesystem to represent + * the entire disk in memory. + */ + pgcnt_t *page_array; + + mark_t min_free; ///< Lowest sequence number of free page + mark_t max_free; ///< Highest sequence number of free page + + disk_size_t disk_size; ///< Size of the disk, in bytes (page_count * page_size). disk_size_t free_bytes; ///< Free space on the disk. + /* TODO add other fields. */ } BattFsSuper; +bool battfs_init(struct BattFsSuper *d); + #endif /* FS_BATTFS_H */