use embedded_storage::nor_flash::{ErrorType, NorFlash, NorFlashError, ReadNorFlash};
use embedded_storage_async::nor_flash::{NorFlash as AsyncNorFlash, ReadNorFlash as AsyncReadNorFlash};
pub struct ConcatFlash<First, Second>(First, Second);
impl<First, Second> ConcatFlash<First, Second> {
pub fn new(first: First, second: Second) -> Self {
Self(first, second)
}
}
const fn get_read_size(first_read_size: usize, second_read_size: usize) -> usize {
if first_read_size != second_read_size {
panic!("The read size for the concatenated flashes must be the same");
}
first_read_size
}
const fn get_write_size(first_write_size: usize, second_write_size: usize) -> usize {
if first_write_size != second_write_size {
panic!("The write size for the concatenated flashes must be the same");
}
first_write_size
}
const fn get_max_erase_size(first_erase_size: usize, second_erase_size: usize) -> usize {
let max_erase_size = if first_erase_size > second_erase_size {
first_erase_size
} else {
second_erase_size
};
if max_erase_size % first_erase_size != 0 || max_erase_size % second_erase_size != 0 {
panic!("The erase sizes for the concatenated flashes must have have a gcd equal to the max erase size");
}
max_erase_size
}
impl<First, Second, E> ErrorType for ConcatFlash<First, Second>
where
First: ErrorType<Error = E>,
Second: ErrorType<Error = E>,
E: NorFlashError,
{
type Error = E;
}
impl<First, Second, E> ReadNorFlash for ConcatFlash<First, Second>
where
First: ReadNorFlash<Error = E>,
Second: ReadNorFlash<Error = E>,
E: NorFlashError,
{
const READ_SIZE: usize = get_read_size(First::READ_SIZE, Second::READ_SIZE);
fn read(&mut self, mut offset: u32, mut bytes: &mut [u8]) -> Result<(), E> {
if offset < self.0.capacity() as u32 {
let len = core::cmp::min(self.0.capacity() - offset as usize, bytes.len());
self.0.read(offset, &mut bytes[..len])?;
offset += len as u32;
bytes = &mut bytes[len..];
}
if !bytes.is_empty() {
self.1.read(offset - self.0.capacity() as u32, bytes)?;
}
Ok(())
}
fn capacity(&self) -> usize {
self.0.capacity() + self.1.capacity()
}
}
impl<First, Second, E> NorFlash for ConcatFlash<First, Second>
where
First: NorFlash<Error = E>,
Second: NorFlash<Error = E>,
E: NorFlashError,
{
const WRITE_SIZE: usize = get_write_size(First::WRITE_SIZE, Second::WRITE_SIZE);
const ERASE_SIZE: usize = get_max_erase_size(First::ERASE_SIZE, Second::ERASE_SIZE);
fn write(&mut self, mut offset: u32, mut bytes: &[u8]) -> Result<(), E> {
if offset < self.0.capacity() as u32 {
let len = core::cmp::min(self.0.capacity() - offset as usize, bytes.len());
self.0.write(offset, &bytes[..len])?;
offset += len as u32;
bytes = &bytes[len..];
}
if !bytes.is_empty() {
self.1.write(offset - self.0.capacity() as u32, bytes)?;
}
Ok(())
}
fn erase(&mut self, mut from: u32, to: u32) -> Result<(), E> {
if from < self.0.capacity() as u32 {
let to = core::cmp::min(self.0.capacity() as u32, to);
self.0.erase(from, to)?;
from = self.0.capacity() as u32;
}
if from < to {
self.1
.erase(from - self.0.capacity() as u32, to - self.0.capacity() as u32)?;
}
Ok(())
}
}
impl<First, Second, E> AsyncReadNorFlash for ConcatFlash<First, Second>
where
First: AsyncReadNorFlash<Error = E>,
Second: AsyncReadNorFlash<Error = E>,
E: NorFlashError,
{
const READ_SIZE: usize = get_read_size(First::READ_SIZE, Second::READ_SIZE);
async fn read(&mut self, mut offset: u32, mut bytes: &mut [u8]) -> Result<(), E> {
if offset < self.0.capacity() as u32 {
let len = core::cmp::min(self.0.capacity() - offset as usize, bytes.len());
self.0.read(offset, &mut bytes[..len]).await?;
offset += len as u32;
bytes = &mut bytes[len..];
}
if !bytes.is_empty() {
self.1.read(offset - self.0.capacity() as u32, bytes).await?;
}
Ok(())
}
fn capacity(&self) -> usize {
self.0.capacity() + self.1.capacity()
}
}
impl<First, Second, E> AsyncNorFlash for ConcatFlash<First, Second>
where
First: AsyncNorFlash<Error = E>,
Second: AsyncNorFlash<Error = E>,
E: NorFlashError,
{
const WRITE_SIZE: usize = get_write_size(First::WRITE_SIZE, Second::WRITE_SIZE);
const ERASE_SIZE: usize = get_max_erase_size(First::ERASE_SIZE, Second::ERASE_SIZE);
async fn write(&mut self, mut offset: u32, mut bytes: &[u8]) -> Result<(), E> {
if offset < self.0.capacity() as u32 {
let len = core::cmp::min(self.0.capacity() - offset as usize, bytes.len());
self.0.write(offset, &bytes[..len]).await?;
offset += len as u32;
bytes = &bytes[len..];
}
if !bytes.is_empty() {
self.1.write(offset - self.0.capacity() as u32, bytes).await?;
}
Ok(())
}
async fn erase(&mut self, mut from: u32, to: u32) -> Result<(), E> {
if from < self.0.capacity() as u32 {
let to = core::cmp::min(self.0.capacity() as u32, to);
self.0.erase(from, to).await?;
from = self.0.capacity() as u32;
}
if from < to {
self.1
.erase(from - self.0.capacity() as u32, to - self.0.capacity() as u32)
.await?;
}
Ok(())
}
}
#[cfg(test)]
mod tests {
use embedded_storage::nor_flash::{NorFlash, ReadNorFlash};
use super::ConcatFlash;
use crate::flash::mem_flash::MemFlash;
#[test]
fn can_write_and_read_across_flashes() {
let first = MemFlash::<64, 16, 4>::default();
let second = MemFlash::<64, 64, 4>::default();
let mut f = ConcatFlash::new(first, second);
f.write(60, &[0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88]).unwrap();
assert_eq!(&[0x11, 0x22, 0x33, 0x44], &f.0.mem[60..]);
assert_eq!(&[0x55, 0x66, 0x77, 0x88], &f.1.mem[0..4]);
let mut read_buf = [0; 8];
f.read(60, &mut read_buf).unwrap();
assert_eq!(&[0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88], &read_buf);
}
#[test]
fn can_erase_across_flashes() {
let first = MemFlash::<128, 16, 4>::new(0x00);
let second = MemFlash::<128, 64, 4>::new(0x00);
let mut f = ConcatFlash::new(first, second);
f.erase(64, 192).unwrap();
assert_eq!(&[0x00; 64], &f.0.mem[0..64]);
assert_eq!(&[0xff; 64], &f.0.mem[64..128]);
assert_eq!(&[0xff; 64], &f.1.mem[0..64]);
assert_eq!(&[0x00; 64], &f.1.mem[64..128]);
}
}