eLua platform interface - flash access functions

Overview

The flash access section of the platform interface contains functions for writing/erasing the internal flash of the MCU and obtaining information about its internal structure. These functions are used for imlementing WOFS, check here for more information about WOFS.

Functions

platform_flash_get_first_free_block_address platform_flash_get_sector_of_address platform_flash_write platform_s_flash_write platform_flash_get_num_sectors platform_flash_erase_sector

u32 platform_flash_get_first_free_block_address( u32 *psect );

Returns the first free address in the internal flash, aligned to a sector boundary. This function relies on a symbol exported by the linker command file, check here for details. This function. This function is implemented in src/common.c.

Arguments: psect - the sector number of the first free sector in flash will be written in *psect* if psect is not NULL.

Returns: The first free address in the internal flash.

u32 platform_flash_get_sector_of_address( u32 addr );

Returns the flash sector that contains the given address. This function is implemented in src/common.c.

Arguments: none.

Returns: The sector number of the sector that contains addr.

u32 platform_flash_write( const void *from, u32 toaddr, u32 size );

Writes data in the internal flash. This function can automatically take care of flash alignment or size restrictions if INTERNAL_FLASH_WRITE_UNIT_SIZE is properly defined. Check here for more details. This function is implemented in src/common.c. In order to actually write data to the internal flash, this function will call its platform specific (platform_s_flash_write).

Arguments:

  • from - the data to be written in flash.
  • toaddr - flash address to write to.
  • size - length of data in bytes

Returns: The actual number of bytes written in flash.

u32 platform_s_flash_write( const void *from, u32 toaddr, u32 size );

Writes data in the internal flash. This is the platform dependent counterpart of platform_flash_write and it must be implemented by the platform's porting layer. If INTERNAL_FLASH_WRITE_UNIT_SIZE is properly defined, this function doesn't need to care about data alignment or size restriction issues.

Arguments:

  • from - the data to be written in flash.
  • toaddr - flash address to write to.
  • size - length of data in bytes

Returns: The actual number of bytes written in flash.

u32 platform_flash_get_num_sectors();

Returns the number of sectors in the internal flash. This function is implemented in src/common.c.

Arguments: none.

Returns: The number of sectors in the internal flash.

int platform_flash_erase_sector( u32 sector_id );

Erases a sector from the internal flash. The function does not return until the erase operation is completed. This function is implemented in src/common.c. IMPORTANT: be careful when using this function, as it can erase any sector of the flash. You might damage your eLua image if this function is called with a wrong parameter.

Arguments: sector_id - the number of the sector that will be deleted.

Returns: PLATFORM_OK if the erase operation succeeded, PLATFORM_ERR otherwise.