fix some lints

src/main.rs

@@ -11,7 +11,7 @@
 mod serial;
 
 use core::{
-    mem::{MaybeUninit, transmute},
+    mem::MaybeUninit,
     sync::atomic::{AtomicU8, Ordering},
     task::Poll,
 };
@@ -342,12 +342,22 @@ async fn pio_task(
 fn store_rom(
     flash: &mut Flash<'_, FLASH, impl flash::Mode, FLASH_SIZE>,
 ) -> Result<(), flash::Error> {
-    let offset =
-        unsafe { (INIT_ROM_DATA.as_ptr() as *const u32).offset_from_unsigned(FLASH_BASE) as u32 };
+    let offset = unsafe {
+        u32::try_from(
+            INIT_ROM_DATA
+                .as_ptr()
+                .cast::<u8>()
+                .offset_from_unsigned(FLASH_BASE.cast::<u8>()),
+        )
+        .map_err(|_| flash::Error::OutOfBounds)?
+    };
     let len = size_of_val(&INIT_ROM_DATA).min(ROM_DATA.len());
     defmt::info!("Erasing flash at offset {:#x} with size {:#x}", offset, len);
-    flash.blocking_erase(offset, offset + len as u32)?;
-    let rom_buffer = unsafe { transmute::<&[AtomicU8], &[u8]>(&ROM_DATA[..len]) };
+    flash.blocking_erase(
+        offset,
+        offset + u32::try_from(len).map_err(|_| flash::Error::OutOfBounds)?,
+    )?;
+    let rom_buffer = unsafe { &*(&raw const ROM_DATA[..len] as *const [u8]) };
     defmt::info!("Programming flash with buffer at {}", rom_buffer.as_ptr());
     flash.blocking_write(offset, rom_buffer)?;
     defmt::info!("Successfully commited rom to flash");
@@ -357,12 +367,22 @@ fn store_rom(
 fn load_rom(
     flash: &mut Flash<'_, FLASH, impl flash::Mode, FLASH_SIZE>,
 ) -> Result<(), flash::Error> {
-    let offset =
-        unsafe { (INIT_ROM_DATA.as_ptr() as *const u32).offset_from_unsigned(FLASH_BASE) as u32 };
+    let offset = unsafe {
+        u32::try_from(
+            INIT_ROM_DATA
+                .as_ptr()
+                .cast::<u8>()
+                .offset_from_unsigned(FLASH_BASE.cast::<u8>()),
+        )
+        .map_err(|_| flash::Error::OutOfBounds)?
+    };
     let len = size_of_val(&INIT_ROM_DATA).min(ROM_DATA.len());
     for (i, rom) in ROM_DATA.iter().enumerate().take(len) {
         let mut init = [0u8];
-        flash.blocking_read(offset + i as u32, &mut init)?;
+        flash.blocking_read(
+            offset + u32::try_from(i).map_err(|_| flash::Error::OutOfBounds)?,
+            &mut init,
+        )?;
         let init = init[0];
         rom.store(init, Ordering::SeqCst);
     }