* \author Francesco Sacchi <batt@develer.com>
*
* \brief BattFS: a filesystem for embedded platforms (interface).
+ * TODO: Add detailed filesystem description.
*/
#ifndef FS_BATTFS_H
#define FS_BATTFS_H
#include <cfg/compiler.h> // uintXX_t; STATIC_ASSERT
+#include <algos/rotating_hash.h>
+
+typedef uint16_t filled_t;
+typedef uint16_t page_off_t;
+typedef uint8_t inode_t;
+typedef uint8_t seqnum_t;
+typedef rotating_t battfs_crc_t;
+
+typedef uint16_t battfs_page_t;
/**
* BattFS page header.
- * \note fields order is chosen to comply with alignment.
+ * \note fields order is chosen to comply
+ * with CPU alignment.
*/
typedef struct BattFsPageHeader
{
- uint16_t filled; ///< filled bytes in page.
- uint16_t page_off; ///< Page offset inside file.
- uint8_t inode; ///< File inode (file identifier).
- uint8_t seqnum; ///< bit[1:0]: Page sequence number; bit[7:2] unused for now, must be set to 1.
- uint16_t crc; ///< CRC of the page header.
+ 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.
+ page_off_t page_off; ///< Page offset inside file.
+ battfs_crc_t crc; ///< CRC of the page header.
} BattFsPageHeader;
-STATIC_ASSERT(sizeof(BattFsPageHeader) == 8);
+/* Ensure structure has no padding added */
+STATIC_ASSERT(sizeof(BattFsPageHeader) == sizeof(filled_t) + sizeof(page_off_t)
+ + sizeof(inode_t) + sizeof(seqnum_t) + siezof(BattFsDisk));
/**
* Reset page sequence number of struct \a m to default value (0xFF).
*/
#define INC_SEQ(m) SET_SEQ((m), SEQ(m) + 1)
+/* Fwd decl */
+struct BattFsDisk;
+
+/**
+ * Type interface for disk init function.
+ * \return true if all is ok, false otherwise.
+ */
+typedef bool (*disk_init_t) (struct BattFsDisk *d);
+
+/**
+ * Type interface for disk page read function.
+ * \a page is the page address, \a size the lenght to be read.
+ * \return the number of bytes read.
+ */
+typedef size_t (*disk_page_read_t) (struct BattFsDisk *d, void *buf, battfs_page_t page, size_t size);
+
+/**
+ * Type interface for disk page write function.
+ * \a page is the page address, \a size the lenght to be written.
+ * \return the number of bytes written.
+ */
+typedef size_t (*disk_page_write_t) (struct BattFsDisk *d, const void *buf, battfs_page_t page, size_t size);
+
+/**
+ * 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 BattFsDisk *d, battfs_page_t page);
+
+typedef uint32_t disk_size_t ///< Type for disk sizes.
+
+/**
+ * Context used to describe a disk.
+ * This context structure will be used to access disk.
+ * Must be initialized by hw memory driver.
+ */
+typedef struct BattFsDisk
+{
+ disk_init_t init; ///< Disk init.
+ disk_page_read_t read; ///< Page read.
+ disk_page_write_t write; ///< Page write.
+ disk_page_erase_t erase; ///< Page erase.
+
+ disk_size_t disk_size; ///< Size of the disk, in bytes.
+ disk_size_t free_space; ///< Free space on the disk, in bytes.
+ /* TODO add other fields. */
+} BattFsDisk;
#endif /* FS_BATTFS_H */