diff --git a/embassy-stm32/src/eth/generic_smi.rs b/embassy-stm32/src/eth/generic_smi.rs
index 3b43051f4..239c52634 100644
--- a/embassy-stm32/src/eth/generic_smi.rs
+++ b/embassy-stm32/src/eth/generic_smi.rs
@@ -51,17 +51,63 @@ pub struct GenericSMI {
 
 impl GenericSMI {
     /// Construct the PHY. It assumes the address `phy_addr` in the SMI communication
+    ///
+    /// # Panics
+    /// `phy_addr` must be in range `0..32`
     pub fn new(phy_addr: u8) -> Self {
+        assert!(phy_addr < 32);
         Self {
             phy_addr,
             #[cfg(feature = "time")]
             poll_interval: Duration::from_millis(500),
         }
     }
+
+    /// Construct the PHY. Try to probe all addresses from 0 to 31 during initialization
+    ///
+    /// # Panics
+    /// Initialization panics if PHY didn't respond on any address
+    pub fn new_auto() -> Self {
+        Self {
+            phy_addr: 0xFF,
+            #[cfg(feature = "time")]
+            poll_interval: Duration::from_millis(500),
+        }
+    }
+}
+
+// TODO: Factor out to shared functionality
+fn blocking_delay_us(us: u32) {
+    #[cfg(feature = "time")]
+    embassy_time::block_for(Duration::from_micros(us as u64));
+    #[cfg(not(feature = "time"))]
+    {
+        let freq = unsafe { crate::rcc::get_freqs() }.sys.to_hertz().unwrap().0 as u64;
+        let us = us as u64;
+        let cycles = freq * us / 1_000_000;
+        cortex_m::asm::delay(cycles as u32);
+    }
 }
 
 unsafe impl PHY for GenericSMI {
     fn phy_reset<S: StationManagement>(&mut self, sm: &mut S) {
+        // Detect SMI address
+        if self.phy_addr == 0xFF {
+            for addr in 0..32 {
+                sm.smi_write(addr, PHY_REG_BCR, PHY_REG_BCR_RESET);
+                for _ in 0..10 {
+                    if sm.smi_read(addr, PHY_REG_BCR) & PHY_REG_BCR_RESET != PHY_REG_BCR_RESET {
+                        trace!("Found ETH PHY on address {}", addr);
+                        self.phy_addr = addr;
+                        return;
+                    }
+                    // Give PHY a total of 100ms to respond
+                    blocking_delay_us(10000);
+                }
+            }
+            panic!("PHY did not respond");
+        }
+
         sm.smi_write(self.phy_addr, PHY_REG_BCR, PHY_REG_BCR_RESET);
         while sm.smi_read(self.phy_addr, PHY_REG_BCR) & PHY_REG_BCR_RESET == PHY_REG_BCR_RESET {}
     }
diff --git a/examples/stm32f4/src/bin/eth.rs b/examples/stm32f4/src/bin/eth.rs
index baed96449..a3af8f75c 100644
--- a/examples/stm32f4/src/bin/eth.rs
+++ b/examples/stm32f4/src/bin/eth.rs
@@ -76,7 +76,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PG13,
         p.PB13,
         p.PG11,
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );
 
diff --git a/examples/stm32f7/src/bin/eth.rs b/examples/stm32f7/src/bin/eth.rs
index 1f1eadf37..f353af674 100644
--- a/examples/stm32f7/src/bin/eth.rs
+++ b/examples/stm32f7/src/bin/eth.rs
@@ -77,7 +77,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PG13,
         p.PB13,
         p.PG11,
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );
 
diff --git a/examples/stm32h5/src/bin/eth.rs b/examples/stm32h5/src/bin/eth.rs
index eee1632f5..ead346741 100644
--- a/examples/stm32h5/src/bin/eth.rs
+++ b/examples/stm32h5/src/bin/eth.rs
@@ -80,7 +80,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PG13,
         p.PB15,
         p.PG11,
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );
 
diff --git a/examples/stm32h7/src/bin/eth.rs b/examples/stm32h7/src/bin/eth.rs
index ec3f2c000..6665cd1d0 100644
--- a/examples/stm32h7/src/bin/eth.rs
+++ b/examples/stm32h7/src/bin/eth.rs
@@ -79,7 +79,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PG13, // TX_D0: Transmit Bit 0
         p.PB13, // TX_D1: Transmit Bit 1
         p.PG11, // TX_EN: Transmit Enable
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );
 
diff --git a/examples/stm32h7/src/bin/eth_client.rs b/examples/stm32h7/src/bin/eth_client.rs
index a1558b079..4fbe10f31 100644
--- a/examples/stm32h7/src/bin/eth_client.rs
+++ b/examples/stm32h7/src/bin/eth_client.rs
@@ -81,7 +81,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PG13,
         p.PB13,
         p.PG11,
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );
 
diff --git a/examples/stm32h7/src/bin/eth_client_mii.rs b/examples/stm32h7/src/bin/eth_client_mii.rs
index a352ef444..53f86ac80 100644
--- a/examples/stm32h7/src/bin/eth_client_mii.rs
+++ b/examples/stm32h7/src/bin/eth_client_mii.rs
@@ -86,7 +86,7 @@ async fn main(spawner: Spawner) -> ! {
         p.PC2,
         p.PE2,
         p.PG11,
-        GenericSMI::new(1),
+        GenericSMI::new_auto(),
         mac_addr,
     );
     info!("Device created");
diff --git a/tests/stm32/src/bin/eth.rs b/tests/stm32/src/bin/eth.rs
index bf1922dde..4ab6e234f 100644
--- a/tests/stm32/src/bin/eth.rs
+++ b/tests/stm32/src/bin/eth.rs
@@ -87,7 +87,7 @@ async fn main(spawner: Spawner) {
         #[cfg(feature = "stm32h563zi")]
         p.PB15,
         p.PG11,
-        GenericSMI::new(0),
+        GenericSMI::new_auto(),
         mac_addr,
     );