PFS, the wear-leveled file system on the external NOR flash. More...

Macros
#define	PBL_FS_O_PFS_SKIP_HDR_CRC_CHECK PBL_FS_O_FORMAT(0)
	Skip checking the on-flash header CRCs, for files opened thousands of times.

#define	PBL_FS_O_PFS_USE_PAGE_CACHE PBL_FS_O_FORMAT(1)
	Cache the translation from file pages to flash pages.

Functions
int	pbl_fs_pfs_optimal_size (const char *path, size_t min_size)
	Get the optimal size of a file that can use space beyond a minimum.

Variables
const struct pbl_fs_ops	pbl_fs_pfs_ops
	PFS format, for struct pbl_fs_mount::ops.

Detailed Description

PFS, the wear-leveled file system on the external NOR flash.

Files have a fixed size, set with pbl_fs_truncate() right after they are created.
There are no directories: file names may contain '/', and only the root of the mount can be listed.
A file is open once at a time, and at most 8 files are open at once.
The flash is NOR: a bit written to 0 stays 0 until the file is rewritten, which PBL_FS_O_REPLACE does safely.
Erasing flash is slow and costs power: avoid deleting and creating files repeatedly.
Removing a file that is open is a fatal error.
Only one PFS can be mounted; the normal firmware mounts it at the root, "/".

Macro Definition Documentation

#define PBL_FS_O_PFS_SKIP_HDR_CRC_CHECK PBL_FS_O_FORMAT(0)

Skip checking the on-flash header CRCs, for files opened thousands of times.

#define PBL_FS_O_PFS_USE_PAGE_CACHE PBL_FS_O_FORMAT(1)

Cache the translation from file pages to flash pages.

Speeds up random access to large files. Best limited to reads, so that heap corruption cannot corrupt the file.

Get the optimal size of a file that can use space beyond a minimum.

Rounds min_size up to use all the space of the flash pages the file takes anyway.

Parameters

path	Absolute path of the file.
min_size	Minimum size in bytes.

Returns: Optimal size in bytes, or negative errno if path is not on a PFS mount.

const struct pbl_fs_ops pbl_fs_pfs_ops

extern

PFS format, for struct pbl_fs_mount::ops.