usb: work on SCSI

embassy-usb/src/class/msc/subclass/scsi/block_device.rs

@@ -0,0 +1,19 @@
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BlockDeviceError {
+    // TODO
+}
+
+pub trait BlockDevice {
+    /// The number of bytes per block. This determines the size of the buffer passed
+    /// to read/write functions
+    fn block_size(&self) -> usize;
+
+    /// Number of blocks in device (max LBA index)
+    fn num_blocks(&self) -> u32;
+
+    /// Read the block indicated by `lba` into the provided buffer
+    fn read_block(&self, lba: u32, block: &mut [u8]) -> Result<(), BlockDeviceError>;
+
+    /// Write the `block` buffer to the block indicated by `lba`
+    fn write_block(&mut self, lba: u32, block: &[u8]) -> Result<(), BlockDeviceError>;
+}