A buffer that persists between boot. Inspired by panic-persist
A region in RAM is reseved for this buffer. Your linker script should make sure the start and end of the buffer are outside of other sections
You need to create a new reserved section for the buffer and make sure it's outside of other sections to avoid zero initializations.
memory.x file before modification:
MEMORY
{
/* NOTE 1 K = 1 KiBi = 1024 bytes */
FLASH : ORIGIN = 0x00000000, LENGTH = 1024K
RAM : ORIGIN = 0x20000000, LENGTH = 128K
}
memory.x file after modification to hold a 1K region:
MEMORY
{
/* NOTE 1 K = 1 KiBi = 1024 bytes */
FLASH : ORIGIN = 0x00000000, LENGTH = 1024K
RAM : ORIGIN = 0x20000000, LENGTH = 128K - 1K
PERSISTENT_BUFF: ORIGIN = ORIGIN(RAM) + LENGTH(RAM), LENGTH = 1K
}
_persistent_buff_start = ORIGIN(PERSISTENT_BUFF);
_persistent_buff_end = ORIGIN(PERSISTENT_BUFF) + LENGTH(PERSISTENT_BUFF);
#![no_std]
#[entry]
fn main() -> ! {
let mut pbuff = persistent_buff::PersistentBuff::take_managed().unwrap();
// Trivial way to initialize is to fill it with 0
let buff = pbuff.validate(|b| b.fill(0));
buff[0] = (buff[0] % 255) + 1;
info!("Value is now {}", buff[0]);
}Licensed under either of
-
Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
-
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.