Flash translation layer

Contiguous virtual address space for PFS over several flash regions. More...

Functions
void	ftl_add_region (uint32_t region_start, uint32_t region_end, bool erase_new_region)
	Append a flash region to the translation space.
uint32_t	ftl_get_size (void)
	Get the size of the translation space.
void	ftl_erase_sector (uint32_t size, uint32_t offset)
	Erase a sector of the translation space.
void	ftl_erase_subsector (uint32_t size, uint32_t offset)
	Erase a subsector of the translation space.
void	ftl_read (void *buffer, size_t size, uint32_t offset)
	Read from the translation space.
void	ftl_write (const void *buffer, size_t size, uint32_t offset)
	Write to the translation space.
void	ftl_format (void)
	Format all regions of the translation space.
void	ftl_populate_region_list (void)
	Build the translation space at boot.

Detailed Description

Contiguous virtual address space for PFS over several flash regions.

Lets PFS grow into multiple flash regions while keeping a contiguous virtual address space. Regions are added in the order of the board's filesystem region list. On boot, the regions where PFS is already active are added as they are; the remaining ones are erased and then added, growing the filesystem.

Function Documentation

ftl_add_region()

void ftl_add_region	(	uint32_t	region_start,
		uint32_t	region_end,
		bool	erase_new_region
	)

Append a flash region to the translation space.

The region must be the next one in the filesystem region list; otherwise the call is ignored. Grows the PFS size by region_end - region_start.

Parameters

region_start	Start address of the region.
region_end	End address of the region, exclusive.
erase_new_region	Erase the region before adding it.

ftl_erase_sector()

void ftl_erase_sector	(	uint32_t	size,
		uint32_t	offset
	)

Erase a sector of the translation space.

Parameters

size	Size of the area to erase, must equal SECTOR_SIZE_BYTES (asserted).
offset	Virtual offset of the sector.

ftl_erase_subsector()

void ftl_erase_subsector	(	uint32_t	size,
		uint32_t	offset
	)

Erase a subsector of the translation space.

Parameters

size	Size of the area to erase, must equal SUBSECTOR_SIZE_BYTES (asserted).
offset	Virtual offset of the subsector.

ftl_format()

void ftl_format

(

void

)

Format all regions of the translation space.

Currently does nothing; use pfs_format() to erase the filesystem.

ftl_get_size()

uint32_t ftl_get_size

(

void

)

Get the size of the translation space.

Returns

Size in bytes.

ftl_populate_region_list()

void ftl_populate_region_list

(

void

)

Build the translation space at boot.

Adds the regions where PFS already exists, runs pfs_reboot_cleanup(), then erases and adds the remaining regions. Called by pfs_init().

ftl_read()

void ftl_read	(	void *	buffer,
		size_t	size,
		uint32_t	offset
	)

Read from the translation space.

Parameters

[out]	buffer	Destination buffer.
	size	Number of bytes to read, at most the size of buffer.
	offset	Virtual offset to read from.

ftl_write()

void ftl_write	(	const void *	buffer,
		size_t	size,
		uint32_t	offset
	)

Write to the translation space.

Parameters

buffer	Data to write.
size	Number of bytes to write, at most the size of buffer.
offset	Virtual offset to write to.