1 files changed, 28 insertions, 0 deletions

diff --git a/embassy-stm32/src/backup_sram.rs b/embassy-stm32/src/backup_sram.rs
new file mode 100644
index 000000000..31b373c6c
--- /dev/null
+++ b/embassy-stm32/src/backup_sram.rs
@@ -0,0 +1,28 @@
+//! Battary backed SRAM
+
+use core::slice;
+
+use embassy_hal_internal::Peri;
+
+use crate::_generated::{BKPSRAM_BASE, BKPSRAM_SIZE};
+use crate::peripherals::BKPSRAM;
+
+/// Struct used to initilize backup sram
+pub struct BackupMemory {}
+
+impl BackupMemory {
+    /// Setup battery backed sram
+    ///
+    /// Returns slice to sram and whether the sram was retained
+    pub fn new(_backup_sram: Peri<'static, BKPSRAM>) -> (&'static mut [u8], bool) {
+        // Assert bksram has been enabled in rcc
+        assert!(crate::pac::PWR.bdcr().read().bren() == crate::pac::pwr::vals::Retention::PRESERVED);
+
+        unsafe {
+            (
+                slice::from_raw_parts_mut(BKPSRAM_BASE as *mut u8, BKPSRAM_SIZE),
+                critical_section::with(|_| crate::rcc::BKSRAM_RETAINED),
+            )
+        }
+    }
+}