Add F7 flash and bootloader support

embassy-stm32/src/flash/f7.rs

@@ -0,0 +1,138 @@
+use core::convert::TryInto;
+use core::ptr::write_volatile;
+
+use atomic_polyfill::{fence, Ordering};
+
+use crate::flash::Error;
+use crate::pac;
+
+pub(crate) unsafe fn lock() {
+    pac::FLASH.cr().modify(|w| w.set_lock(true));
+}
+
+pub(crate) unsafe fn unlock() {
+    pac::FLASH.keyr().write(|w| w.set_key(0x4567_0123));
+    pac::FLASH.keyr().write(|w| w.set_key(0xCDEF_89AB));
+}
+
+pub(crate) unsafe fn blocking_write(offset: u32, buf: &[u8]) -> Result<(), Error> {
+    pac::FLASH.cr().write(|w| {
+        w.set_pg(true);
+        w.set_psize(pac::flash::vals::Psize::PSIZE32);
+    });
+
+    let ret = {
+        let mut ret: Result<(), Error> = Ok(());
+        let mut offset = offset;
+        for chunk in buf.chunks(super::WRITE_SIZE) {
+            for val in chunk.chunks(4) {
+                write_volatile(
+                    offset as *mut u32,
+                    u32::from_le_bytes(val[0..4].try_into().unwrap()),
+                );
+                offset += val.len() as u32;
+
+                // prevents parallelism errors
+                fence(Ordering::SeqCst);
+            }
+
+            ret = blocking_wait_ready();
+            if ret.is_err() {
+                break;
+            }
+        }
+        ret
+    };
+
+    pac::FLASH.cr().write(|w| w.set_pg(false));
+
+    ret
+}
+
+pub(crate) unsafe fn blocking_erase(from: u32, to: u32) -> Result<(), Error> {
+    let start_sector = if from >= (super::FLASH_BASE + super::ERASE_SIZE / 2) as u32 {
+        4 + (from - super::FLASH_BASE as u32) / super::ERASE_SIZE as u32
+    } else {
+        (from - super::FLASH_BASE as u32) / (super::ERASE_SIZE as u32 / 8)
+    };
+
+    let end_sector = if to >= (super::FLASH_BASE + super::ERASE_SIZE / 2) as u32 {
+        4 + (to - super::FLASH_BASE as u32) / super::ERASE_SIZE as u32
+    } else {
+        (to - super::FLASH_BASE as u32) / (super::ERASE_SIZE as u32 / 8)
+    };
+
+    for sector in start_sector..end_sector {
+        let ret = erase_sector(sector as u8);
+        if ret.is_err() {
+            return ret;
+        }
+    }
+
+    Ok(())
+}
+
+unsafe fn erase_sector(sector: u8) -> Result<(), Error> {
+    pac::FLASH.cr().modify(|w| {
+        w.set_ser(true);
+        w.set_snb(sector)
+    });
+
+    pac::FLASH.cr().modify(|w| {
+        w.set_strt(true);
+    });
+
+    let ret: Result<(), Error> = blocking_wait_ready();
+
+    pac::FLASH.cr().modify(|w| w.set_ser(false));
+
+    clear_all_err();
+
+    ret
+}
+
+pub(crate) unsafe fn clear_all_err() {
+    pac::FLASH.sr().modify(|w| {
+        if w.erserr() {
+            w.set_erserr(true);
+        }
+        if w.pgperr() {
+            w.set_pgperr(true);
+        }
+        if w.pgaerr() {
+            w.set_pgaerr(true);
+        }
+        if w.wrperr() {
+            w.set_wrperr(true);
+        }
+        if w.eop() {
+            w.set_eop(true);
+        }
+    });
+}
+
+pub(crate) unsafe fn blocking_wait_ready() -> Result<(), Error> {
+    loop {
+        let sr = pac::FLASH.sr().read();
+
+        if !sr.bsy() {
+            if sr.erserr() {
+                return Err(Error::Seq);
+            }
+
+            if sr.pgperr() {
+                return Err(Error::Parallelism);
+            }
+
+            if sr.pgaerr() {
+                return Err(Error::Unaligned);
+            }
+
+            if sr.wrperr() {
+                return Err(Error::Protected);
+            }
+
+            return Ok(());
+        }
+    }
+}