nrf54l: Allow debug access from firmware sid3

This adds support for the
embassy-rs · Dec 25, 2024 · c306d45 · c306d45
1 parent fd2b6c8
commit c306d45
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Showing 2 changed files with 81 additions and 10 deletions.
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
@@ -507,7 +507,6 @@ pub fn init(config: config::Config) -> Peripherals {
     let mut needs_reset = false;
 
     // Setup debug protection.
-    #[cfg(not(feature = "_nrf54l"))] // TODO
     #[cfg(not(feature = "_nrf51"))]
     match config.debug {
         config::Debug::Allowed => {
@@ -549,18 +548,90 @@ pub fn init(config: config::Config) -> Peripherals {
                 }
             }
 
+            #[cfg(feature = "_nrf54l")]
+            {
+                use crate::pac::tampc::regs::DomainDbgenCtrl;
+                use crate::pac::tampc::regs::NidenCtrl;
+                use crate::pac::tampc::regs::SpidenCtrl;
+                use crate::pac::tampc::regs::SpnidenCtrl;
+                use crate::pac::tampc::vals::DomainDbgenCtrlValue;
+
+                // UICR cannot be written here, because it can only be written once after an erase all.
+                // The erase all value means that debug access is allowed if permitted by the firmware.
+
+                // Write to TAMPC to permit debug access
+                //
+                // See https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/debug.html#ariaid-title6
+
+                let p = pac::TAMPC;
+
+                // Unlock dbgen
+                let mut writeprotect_clear = DomainDbgenCtrl::default();
+                writeprotect_clear.set_key(crate::pac::tampc::vals::DomainDbgenCtrlKey::KEY);
+                writeprotect_clear.set_writeprotection(crate::pac::tampc::vals::DomainDbgenCtrlWriteprotection::CLEAR);
+
+                let mut debug_enable = DomainDbgenCtrl::default();
+                debug_enable.set_key(crate::pac::tampc::vals::DomainDbgenCtrlKey::KEY);
+                debug_enable.set_value(DomainDbgenCtrlValue::HIGH);
+
+                p.protect().domain(0).dbgen().ctrl().write_value(writeprotect_clear);
+                p.protect().domain(0).dbgen().ctrl().write_value(debug_enable);
+
+                // Unlock niden
+                //
+                // Reuse values from dbgen disable
+                p.protect()
+                    .domain(0)
+                    .niden()
+                    .ctrl()
+                    .write_value(NidenCtrl(writeprotect_clear.0));
+                p.protect()
+                    .domain(0)
+                    .niden()
+                    .ctrl()
+                    .write_value(NidenCtrl(debug_enable.0));
+
+                p.protect()
+                    .domain(0)
+                    .spiden()
+                    .ctrl()
+                    .write_value(SpidenCtrl(writeprotect_clear.0));
+                p.protect()
+                    .domain(0)
+                    .spiden()
+                    .ctrl()
+                    .write_value(SpidenCtrl(debug_enable.0));
+
+                p.protect()
+                    .domain(0)
+                    .spniden()
+                    .ctrl()
+                    .write_value(SpnidenCtrl(writeprotect_clear.0));
+                p.protect()
+                    .domain(0)
+                    .spniden()
+                    .ctrl()
+                    .write_value(SpnidenCtrl(debug_enable.0));
+            }
+
             // nothing to do on the nrf9160, debug is allowed by default.
         }
-        config::Debug::Disallowed => unsafe {
-            // UICR.APPROTECT = Enabled
-            let res = uicr_write(consts::UICR_APPROTECT, consts::APPROTECT_ENABLED);
-            needs_reset |= res == WriteResult::Written;
-            #[cfg(any(feature = "_nrf5340-app", feature = "_nrf91"))]
-            {
-                let res = uicr_write(consts::UICR_SECUREAPPROTECT, consts::APPROTECT_ENABLED);
+        config::Debug::Disallowed => {
+            // TODO: Handle nRF54L
+            //       By default, debug access is not allowed if the firmware doesn't allow it.
+            //       Code could be added here to disable debug access in UICR as well.
+            #[cfg(not(feature = "_nrf54l"))]
+            unsafe {
+                // UICR.APPROTECT = Enabled
+                let res = uicr_write(consts::UICR_APPROTECT, consts::APPROTECT_ENABLED);
                 needs_reset |= res == WriteResult::Written;
+                #[cfg(any(feature = "_nrf5340-app", feature = "_nrf91"))]
+                {
+                    let res = uicr_write(consts::UICR_SECUREAPPROTECT, consts::APPROTECT_ENABLED);
+                    needs_reset |= res == WriteResult::Written;
+                }
             }
-        },
+        }
         config::Debug::NotConfigured => {}
     }
 

diff --git a/examples/nrf54l15/.cargo/config.toml b/examples/nrf54l15/.cargo/config.toml
@@ -1,6 +1,6 @@
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 # replace nRF82840_xxAA with your chip as listed in `probe-rs chip list`
-runner = "../../sshprobe.sh"
+runner = "probe-rs run --chip nrf54l15"
 
 [build]
 target = "thumbv8m.main-none-eabihf"