Struct FlashGeometry 

pub struct FlashGeometry {
    pub erase_block_size: u32,
    pub write_page_size: u32,
    pub total_blocks: u32,
    pub max_erase_cycles: u32,
}

Describes the physical geometry of a flash device.

Users must provide accurate geometry for their specific flash chip. Incorrect values (especially erase_block_size or write_page_size) will cause data corruption.

Fields

erase_block_size: u32

Size of one erase block in bytes. Typical: 4096 (NOR) or 131072 (NAND).

write_page_size: u32

Size of one write page in bytes. For NOR flash this typically equals erase_block_size. For NAND, typical values are 2048 or 4096.

total_blocks: u32

Total number of erase blocks on the device.

max_erase_cycles: u32

Maximum erase cycles per block before wear-out. Typical: 100,000 (NOR) or 3,000 to 10,000 (NAND).

Implementations

impl FlashGeometry

pub fn total_capacity(&self) -> u64

Total device capacity in bytes.

pub fn pages_per_block(&self) -> u32

Number of write pages per erase block.

pub fn reserved_blocks(&self) -> u32

Compute the number of physical blocks reserved for FTL metadata.

This covers two journal slots (double-buffered) plus 2 spare blocks for garbage collection during block replacement.

pub fn logical_block_count(&self) -> u32

Number of logical blocks available for data storage after reserving FTL overhead and COW headroom.

The COW headroom ensures that even when all logical blocks are allocated, allocate_block() can still find free physical blocks for copy-on-write operations.

Trait Implementations

impl Clone for FlashGeometry

fn clone(&self) -> FlashGeometry

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FlashGeometry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for FlashGeometry