wpan/mac: use slice view to avoid copy

embassy-stm32-wpan/src/mac/commands.rs

@@ -1,15 +1,16 @@
+use core::{mem, slice};
+
 use super::opcodes::OpcodeM4ToM0;
 use super::typedefs::{
     AddressMode, Capabilities, DisassociationReason, GtsCharacteristics, KeyIdMode, MacAddress, MacChannel, MacStatus,
     PanId, PibId, ScanType, SecurityLevel,
 };
 
-pub trait MacCommand {
+pub trait MacCommand: Sized {
     const OPCODE: OpcodeM4ToM0;
-    const SIZE: usize;
 
-    fn copy_into_slice(&self, buf: &mut [u8]) {
+    fn payload<'a>(&'a self) -> &'a [u8] {
-        unsafe { core::ptr::copy(self as *const _ as *const u8, buf as *mut _ as *mut u8, Self::SIZE) };
+        unsafe { slice::from_raw_parts(self as *const _ as *const u8, mem::size_of::<Self>()) }
     }
 }
 
@@ -41,7 +42,6 @@ pub struct AssociateRequest {
 
 impl MacCommand for AssociateRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeAssociateReq;
-    const SIZE: usize = 25;
 }
 
 /// MLME DISASSOCIATE Request sed to request a disassociation
@@ -70,20 +70,22 @@ pub struct DisassociateRequest {
 
 impl MacCommand for DisassociateRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeDisassociateReq;
-    const SIZE: usize = 24;
 }
 
 /// MLME GET Request used to request a PIB value
 #[repr(C)]
+#[derive(Default)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct GetRequest {
     /// the name of the PIB attribute to read
     pub pib_attribute: PibId,
+
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 3],
 }
 
 impl MacCommand for GetRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeGetReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME GTS Request used to request and maintain GTSs
@@ -104,19 +106,20 @@ pub struct GtsRequest {
 
 impl MacCommand for GtsRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeGetReq;
-    const SIZE: usize = 12;
 }
 
 #[repr(C)]
+#[derive(Default)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct ResetRequest {
     /// MAC PIB attributes are set to their default values or not during reset
     pub set_default_pib: bool,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 3],
 }
 
 impl MacCommand for ResetRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeResetReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME RX ENABLE Request used to request that the receiver is either enabled
@@ -129,6 +132,8 @@ pub struct RxEnableRequest {
     /// configure the transceiver to RX with ranging for a value of
     /// RANGING_ON or to not enable ranging for RANGING_OFF
     pub ranging_rx_control: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 2],
     /// number of symbols measured before the receiver is to be enabled or disabled
     pub rx_on_time: [u8; 4],
     /// number of symbols for which the receiver is to be enabled
@@ -137,19 +142,6 @@ pub struct RxEnableRequest {
 
 impl MacCommand for RxEnableRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeRxEnableReq;
-    const SIZE: usize = 12;
-
-    fn copy_into_slice(&self, buf: &mut [u8]) {
-        buf[0] = self.defer_permit as u8;
-        buf[1] = self.ranging_rx_control as u8;
-
-        // stuffing to keep 32bit alignment
-        buf[2] = 0;
-        buf[3] = 0;
-
-        buf[4..8].copy_from_slice(&self.rx_on_time);
-        buf[8..12].copy_from_slice(&self.rx_on_duration);
-    }
 }
 
 /// MLME SCAN Request used to initiate a channel scan over a given list of channels
@@ -172,11 +164,12 @@ pub struct ScanRequest {
     pub key_id_mode: KeyIdMode,
     /// index of the key to be used
     pub key_index: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 2],
 }
 
 impl MacCommand for ScanRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeScanReq;
-    const SIZE: usize = 20;
 }
 
 /// MLME SET Request used to attempt to write the given value to the indicated PIB attribute
@@ -191,13 +184,12 @@ pub struct SetRequest {
 
 impl MacCommand for SetRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeSetReq;
-    const SIZE: usize = 8;
 }
 
 /// MLME START Request used by the FFDs to intiate a new PAN or to begin using a new superframe
 /// configuration
-#[derive(Default)]
 #[repr(C)]
+#[derive(Default)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct StartRequest {
     /// PAN indentifier to used by the device
@@ -236,7 +228,6 @@ pub struct StartRequest {
 
 impl MacCommand for StartRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeStartReq;
-    const SIZE: usize = 35;
 }
 
 /// MLME SYNC Request used to synchronize with the coordinator by acquiring and, if
@@ -253,11 +244,12 @@ pub struct SyncRequest {
     ///
     /// `false` if the MLME is to synchronize with only the next beacon
     pub track_beacon: bool,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 1],
 }
 
 impl MacCommand for SyncRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeSyncReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME POLL Request propmts the device to request data from the coordinator
@@ -278,11 +270,12 @@ pub struct PollRequest {
     pub key_source: [u8; 8],
     /// PAN identifier of the coordinator
     pub coord_pan_id: PanId,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 2],
 }
 
 impl MacCommand for PollRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmePollReq;
-    const SIZE: usize = 24;
 }
 
 /// MLME DPS Request allows the next higher layer to request that the PHY utilize a
@@ -297,33 +290,38 @@ pub struct DpsRequest {
     /// the number of symbols for which the transmitter and receiver will utilize the
     /// respective DPS indices
     dps_index_duration: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 1],
 }
 
 impl MacCommand for DpsRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeDpsReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME SOUNDING request primitive which is used by the next higher layer to request that
 /// the PHY respond with channel sounding information
 #[repr(C)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct SoundingRequest;
+pub struct SoundingRequest {
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 4],
+}
 
 impl MacCommand for SoundingRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeSoundingReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME CALIBRATE request primitive which used  to obtain the results of a ranging
 /// calibration request from an RDEV
 #[repr(C)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct CalibrateRequest;
+pub struct CalibrateRequest {
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 4],
+}
 
 impl MacCommand for CalibrateRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeCalibrateReq;
-    const SIZE: usize = 4;
 }
 
 /// MCPS DATA Request used for MAC data related requests from the application
@@ -370,6 +368,15 @@ pub struct DataRequest {
     pub datrate: u8,
 }
 
+impl DataRequest {
+    pub fn set_buffer<'a>(&'a mut self, buf: &'a [u8]) -> &mut Self {
+        self.msdu_ptr = &buf as *const _ as *const u8;
+        self.msdu_length = buf.len() as u8;
+
+        self
+    }
+}
+
 impl Default for DataRequest {
     fn default() -> Self {
         Self {
@@ -397,7 +404,6 @@ impl Default for DataRequest {
 
 impl MacCommand for DataRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::McpsDataReq;
-    const SIZE: usize = 40;
 }
 
 /// for MCPS PURGE Request used to purge an MSDU from the transaction queue
@@ -407,11 +413,12 @@ pub struct PurgeRequest {
     /// the handle associated with the MSDU to be purged from the transaction
     /// queue
     pub msdu_handle: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 3],
 }
 
 impl MacCommand for PurgeRequest {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::McpsPurgeReq;
-    const SIZE: usize = 4;
 }
 
 /// MLME ASSOCIATE Response used to initiate a response to an MLME-ASSOCIATE.indication
@@ -434,11 +441,12 @@ pub struct AssociateResponse {
     pub key_id_mode: KeyIdMode,
     /// the index of the key to be used
     pub key_index: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 2],
 }
 
 impl MacCommand for AssociateResponse {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeAssociateRes;
-    const SIZE: usize = 24;
 }
 
 /// MLME ORPHAN Response used to respond to the MLME ORPHAN Indication
@@ -459,9 +467,10 @@ pub struct OrphanResponse {
     pub key_id_mode: KeyIdMode,
     /// the index of the key to be used
     pub key_index: u8,
+    /// byte stuffing to keep 32 bit alignment
+    pub a_stuffing: [u8; 2],
 }
 
 impl MacCommand for OrphanResponse {
     const OPCODE: OpcodeM4ToM0 = OpcodeM4ToM0::MlmeOrphanRes;
-    const SIZE: usize = 24;
 }

embassy-stm32-wpan/src/mac/typedefs.rs

@@ -37,9 +37,11 @@ numeric_enum! {
 numeric_enum! {
     #[repr(u8)]
     /// this enum contains all the MAC PIB Ids
+    #[derive(Default)]
     #[cfg_attr(feature = "defmt", derive(defmt::Format))]
     pub enum PibId {
         // PHY
+        #[default]
         CurrentChannel = 0x00,
         ChannelsSupported = 0x01,
         TransmitPower = 0x02,

embassy-stm32-wpan/src/sub/mac.rs

@@ -85,12 +85,7 @@ impl Mac {
     where
         T: MacCommand,
     {
-        let mut payload = [0u8; MAX_PACKET_SIZE];
+        let response = self.tl_write_and_get_response(T::OPCODE as u16, cmd.payload()).await;
-        cmd.copy_into_slice(&mut payload);
-
-        let response = self
-            .tl_write_and_get_response(T::OPCODE as u16, &payload[..T::SIZE])
-            .await;
 
         if response == 0x00 {
             Ok(())
@@ -107,8 +102,6 @@ impl Mac {
     }
 }
 
-const MAX_PACKET_SIZE: usize = 255;
-
 impl evt::MemoryManager for Mac {
     /// SAFETY: passing a pointer to something other than a managed event packet is UB
     unsafe fn drop_event_packet(_: *mut EvtPacket) {

examples/stm32wb/src/bin/mac_ffd.rs

@@ -67,7 +67,10 @@ async fn main(spawner: Spawner) {
 
     info!("resetting");
     mbox.mac_subsystem
-        .send_command(&ResetRequest { set_default_pib: true })
+        .send_command(&ResetRequest {
+            set_default_pib: true,
+            ..Default::default()
+        })
         .await
         .unwrap();
     let evt = mbox.mac_subsystem.read().await;

examples/stm32wb/src/bin/mac_rfd.rs

@@ -69,7 +69,10 @@ async fn main(spawner: Spawner) {
 
     info!("resetting");
     mbox.mac_subsystem
-        .send_command(&ResetRequest { set_default_pib: true })
+        .send_command(&ResetRequest {
+            set_default_pib: true,
+            ..Default::default()
+        })
         .await
         .unwrap();
     let evt = mbox.mac_subsystem.read().await;
@@ -91,6 +94,7 @@ async fn main(spawner: Spawner) {
     mbox.mac_subsystem
         .send_command(&GetRequest {
             pib_attribute: PibId::ExtendedAddress,
+            ..Default::default()
         })
         .await
         .unwrap();
@@ -141,11 +145,10 @@ async fn main(spawner: Spawner) {
     info!("{:#x}", evt);
 
     info!("sending data");
-    let mut data_buffer = [0u8; 256];
     let data = b"Hello from embassy!";
-    data_buffer[..data.len()].copy_from_slice(data);
     mbox.mac_subsystem
-        .send_command(&DataRequest {
+        .send_command(
+            DataRequest {
                 src_addr_mode: AddressMode::Short,
                 dst_addr_mode: AddressMode::Short,
                 dst_pan_id: PanId([0x1A, 0xAA]),
@@ -153,11 +156,11 @@ async fn main(spawner: Spawner) {
                 msdu_handle: 0x02,
                 ack_tx: 0x00,
                 gts_tx: false,
-            msdu_ptr: &data_buffer as *const _ as *const u8,
-            msdu_length: data.len() as u8,
                 security_level: SecurityLevel::Unsecure,
                 ..Default::default()
-        })
+            }
+            .set_buffer(data),
+        )
         .await
         .unwrap();
     let evt = mbox.mac_subsystem.read().await;

tests/stm32/src/bin/wpan_mac.rs

@@ -49,7 +49,10 @@ async fn main(spawner: Spawner) {
 
     info!("resetting");
     mbox.mac_subsystem
-        .send_command(&ResetRequest { set_default_pib: true })
+        .send_command(&ResetRequest {
+            set_default_pib: true,
+            ..Default::default()
+        })
         .await
         .unwrap();
     let evt = mbox.mac_subsystem.read().await;
@@ -71,6 +74,7 @@ async fn main(spawner: Spawner) {
     mbox.mac_subsystem
         .send_command(&GetRequest {
             pib_attribute: PibId::ExtendedAddress,
+            ..Default::default()
         })
         .await
         .unwrap();