Merge pull request #852 from embassy-rs/rp-flex

rp: add Flex gpio

7 files changed, 804 insertions, 104 deletions

diff --git a/ci.sh b/ci.sh
index 6d7c9b046..315b60ef7 100755
--- a/ci.sh
+++ b/ci.sh
@@ -104,6 +104,7 @@ cargo batch  \
     --- build --release --manifest-path tests/stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32h755zi --out-dir out/tests/nucleo-stm32h755zi \
     --- build --release --manifest-path tests/stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32wb55rg --out-dir out/tests/nucleo-stm32wb55rg \
     --- build --release --manifest-path tests/stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32u585ai --out-dir out/tests/iot-stm32u585ai \
+    --- build --release --manifest-path tests/rp/Cargo.toml --target thumbv6m-none-eabi --out-dir out/tests/rpi-pico \
 
 
 function run_elf {
diff --git a/embassy-rp/src/gpio.rs b/embassy-rp/src/gpio.rs
index ae771e849..131330e79 100644
--- a/embassy-rp/src/gpio.rs
+++ b/embassy-rp/src/gpio.rs
@@ -30,156 +30,147 @@ pub enum Bank {
 }
 
 pub struct Input<'d, T: Pin> {
-    pin: T,
-    phantom: PhantomData<&'d mut T>,
+    pin: Flex<'d, T>,
 }
 
 impl<'d, T: Pin> Input<'d, T> {
     pub fn new(pin: impl Unborrow<Target = T> + 'd, pull: Pull) -> Self {
-        unborrow!(pin);
-
-        unsafe {
-            pin.pad_ctrl().write(|w| {
-                w.set_ie(true);
-                match pull {
-                    Pull::Up => w.set_pue(true),
-                    Pull::Down => w.set_pde(true),
-                    Pull::None => {}
-                }
-            });
-
-            // disable output in SIO, to use it as input
-            pin.sio_oe().value_clr().write_value(1 << pin.pin());
-
-            pin.io().ctrl().write(|w| {
-                w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::SIO_0.0);
-            });
-        }
-
-        Self {
-            pin,
-            phantom: PhantomData,
-        }
+        let mut pin = Flex::new(pin);
+        pin.set_as_input();
+        pin.set_pull(pull);
+        Self { pin }
     }
 
     pub fn is_high(&self) -> bool {
-        !self.is_low()
+        self.pin.is_high()
     }
 
     pub fn is_low(&self) -> bool {
-        let val = 1 << self.pin.pin();
-        unsafe { self.pin.sio_in().read() & val == 0 }
-    }
-}
-
-impl<'d, T: Pin> Drop for Input<'d, T> {
-    fn drop(&mut self) {
-        // todo
+        self.pin.is_low()
     }
 }
 
 pub struct Output<'d, T: Pin> {
-    pin: T,
-    phantom: PhantomData<&'d mut T>,
+    pin: Flex<'d, T>,
 }
 
 impl<'d, T: Pin> Output<'d, T> {
+    #[inline]
     pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
-        unborrow!(pin);
-
-        unsafe {
-            match initial_output {
-                Level::High => pin.sio_out().value_set().write_value(1 << pin.pin()),
-                Level::Low => pin.sio_out().value_clr().write_value(1 << pin.pin()),
-            }
-            pin.sio_oe().value_set().write_value(1 << pin.pin());
-
-            pin.io().ctrl().write(|w| {
-                w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::SIO_0.0);
-            });
+        let mut pin = Flex::new(pin);
+        match initial_output {
+            Level::High => pin.set_high(),
+            Level::Low => pin.set_low(),
         }
 
-        Self {
-            pin,
-            phantom: PhantomData,
-        }
+        pin.set_as_output();
+        Self { pin }
     }
 
     /// Set the output as high.
+    #[inline]
     pub fn set_high(&mut self) {
-        let val = 1 << self.pin.pin();
-        unsafe { self.pin.sio_out().value_set().write_value(val) };
+        self.pin.set_high()
     }
 
     /// Set the output as low.
+    #[inline]
     pub fn set_low(&mut self) {
-        let val = 1 << self.pin.pin();
-        unsafe { self.pin.sio_out().value_clr().write_value(val) };
+        self.pin.set_low()
     }
 
     /// Is the output pin set as high?
+    #[inline]
     pub fn is_set_high(&self) -> bool {
-        !self.is_set_low()
+        self.pin.is_set_high()
     }
 
     /// Is the output pin set as low?
+    #[inline]
     pub fn is_set_low(&self) -> bool {
-        // Reading from SIO: GPIO_OUT gives the last value written.
-        let val = 1 << self.pin.pin();
-        unsafe { (self.pin.sio_out().value().read() & val) == 0 }
+        self.pin.is_set_low()
     }
 
     /// Toggle pin output
     #[inline]
     pub fn toggle(&mut self) {
-        let val = 1 << self.pin.pin();
-        unsafe {
-            self.pin.sio_out().value_xor().write_value(val);
-        }
+        self.pin.toggle()
     }
 }
 
-impl<'d, T: Pin> Drop for Output<'d, T> {
-    fn drop(&mut self) {
-        let val = 1 << self.pin.pin();
-        unsafe {
-            self.pin.sio_out().value_clr().write_value(val);
-            self.pin.sio_oe().value_clr().write_value(val);
-            self.pin.io().ctrl().write(|w| {
-                w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::NULL.0);
-            });
-        };
+/// GPIO output open-drain.
+pub struct OutputOpenDrain<'d, T: Pin> {
+    pin: Flex<'d, T>,
+}
+
+impl<'d, T: Pin> OutputOpenDrain<'d, T> {
+    #[inline]
+    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
+        let mut pin = Flex::new(pin);
+        pin.set_low();
+        match initial_output {
+            Level::High => pin.set_as_input(),
+            Level::Low => pin.set_as_output(),
+        }
+        Self { pin }
+    }
+
+    /// Set the output as high.
+    #[inline]
+    pub fn set_high(&mut self) {
+        // For Open Drain High, disable the output pin.
+        self.pin.set_as_input()
+    }
+
+    /// Set the output as low.
+    #[inline]
+    pub fn set_low(&mut self) {
+        // For Open Drain Low, enable the output pin.
+        self.pin.set_as_output()
+    }
+
+    /// Is the output level high?
+    #[inline]
+    pub fn is_set_high(&self) -> bool {
+        !self.is_set_low()
+    }
+
+    /// Is the output level low?
+    #[inline]
+    pub fn is_set_low(&self) -> bool {
+        self.pin.is_set_as_output()
+    }
+
+    /// Toggle pin output
+    #[inline]
+    pub fn toggle(&mut self) {
+        self.pin.toggle_set_as_output()
     }
 }
 
-/// GPIO output open-drain.
-pub struct OutputOpenDrain<'d, T: Pin> {
+/// GPIO flexible pin.
+///
+/// This pin can be either an input or output pin. The output level register bit will remain
+/// set while not in output mode, so the pin's level will be 'remembered' when it is not in output
+/// mode.
+pub struct Flex<'d, T: Pin> {
     pin: T,
     phantom: PhantomData<&'d mut T>,
 }
 
-impl<'d, T: Pin> OutputOpenDrain<'d, T> {
+impl<'d, T: Pin> Flex<'d, T> {
     #[inline]
-    pub fn new(pin: impl Unborrow<Target = T> + 'd, initial_output: Level) -> Self {
+    pub fn new(pin: impl Unborrow<Target = T> + 'd) -> Self {
         unborrow!(pin);
 
         unsafe {
-            let val = 1 << pin.pin();
+            pin.pad_ctrl().write(|w| {
+                w.set_ie(true);
+            });
+
             pin.io().ctrl().write(|w| {
                 w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::SIO_0.0);
             });
-            pin.sio_out().value_clr().write_value(val);
-
-            match initial_output {
-                Level::High => {
-                    // For Open Drain High, disable the output pin.
-                    pin.sio_oe().value_clr().write_value(val);
-                }
-                Level::Low => {
-                    // For Open Drain Low, enable the output pin.
-                    pin.sio_oe().value_set().write_value(val);
-                }
-            }
         }
 
         Self {
@@ -188,29 +179,79 @@ impl<'d, T: Pin> OutputOpenDrain<'d, T> {
         }
     }
 
-    /// Set the output as high.
     #[inline]
-    pub fn set_high(&mut self) {
-        // For Open Drain High, disable the output pin.
+    fn bit(&self) -> u32 {
+        1 << self.pin.pin()
+    }
+
+    /// Set the pin's pull.
+    #[inline]
+    pub fn set_pull(&mut self, pull: Pull) {
         unsafe {
-            self.pin.sio_oe().value_clr().write_value(1 << self.pin.pin());
+            self.pin.pad_ctrl().write(|w| {
+                w.set_ie(true);
+                match pull {
+                    Pull::Up => w.set_pue(true),
+                    Pull::Down => w.set_pde(true),
+                    Pull::None => {}
+                }
+            });
         }
     }
 
+    /// Put the pin into input mode.
+    ///
+    /// The pull setting is left unchanged.
+    #[inline]
+    pub fn set_as_input(&mut self) {
+        unsafe { self.pin.sio_oe().value_clr().write_value(self.bit()) }
+    }
+
+    /// Put the pin into output mode.
+    ///
+    /// The pin level will be whatever was set before (or low by default). If you want it to begin
+    /// at a specific level, call `set_high`/`set_low` on the pin first.
+    #[inline]
+    pub fn set_as_output(&mut self) {
+        unsafe { self.pin.sio_oe().value_set().write_value(self.bit()) }
+    }
+
+    #[inline]
+    fn is_set_as_output(&self) -> bool {
+        unsafe { (self.pin.sio_oe().value().read() & self.bit()) != 0 }
+    }
+
+    #[inline]
+    pub fn toggle_set_as_output(&mut self) {
+        unsafe { self.pin.sio_oe().value_xor().write_value(self.bit()) }
+    }
+
+    #[inline]
+    pub fn is_high(&self) -> bool {
+        !self.is_low()
+    }
+
+    #[inline]
+    pub fn is_low(&self) -> bool {
+        unsafe { self.pin.sio_in().read() & self.bit() == 0 }
+    }
+
+    /// Set the output as high.
+    #[inline]
+    pub fn set_high(&mut self) {
+        unsafe { self.pin.sio_out().value_set().write_value(self.bit()) }
+    }
+
     /// Set the output as low.
     #[inline]
     pub fn set_low(&mut self) {
-        // For Open Drain Low, enable the output pin.
-        unsafe {
-            self.pin.sio_oe().value_set().write_value(1 << self.pin.pin());
-        }
+        unsafe { self.pin.sio_out().value_clr().write_value(self.bit()) }
     }
 
     /// Is the output level high?
     #[inline]
     pub fn is_set_high(&self) -> bool {
-        let val = 1 << self.pin.pin();
-        unsafe { (self.pin.sio_oe().value().read() & val) == 0 }
+        unsafe { (self.pin.sio_out().value().read() & self.bit()) == 0 }
     }
 
     /// Is the output level low?
@@ -222,9 +263,18 @@ impl<'d, T: Pin> OutputOpenDrain<'d, T> {
     /// Toggle pin output
     #[inline]
     pub fn toggle(&mut self) {
-        let val = 1 << self.pin.pin();
+        unsafe { self.pin.sio_out().value_xor().write_value(self.bit()) }
+    }
+}
+
+impl<'d, T: Pin> Drop for Flex<'d, T> {
+    #[inline]
+    fn drop(&mut self) {
         unsafe {
-            self.pin.sio_out().value_xor().write_value(val);
+            self.pin.pad_ctrl().write(|_| {});
+            self.pin.io().ctrl().write(|w| {
+                w.set_funcsel(pac::io::vals::Gpio0CtrlFuncsel::NULL.0);
+            });
         }
     }
 }
@@ -428,6 +478,48 @@ mod eh02 {
             Ok(self.toggle())
         }
     }
+
+    impl<'d, T: Pin> embedded_hal_02::digital::v2::InputPin for Flex<'d, T> {
+        type Error = Infallible;
+
+        fn is_high(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_high())
+        }
+
+        fn is_low(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_02::digital::v2::OutputPin for Flex<'d, T> {
+        type Error = Infallible;
+
+        fn set_high(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_high())
+        }
+
+        fn set_low(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_02::digital::v2::StatefulOutputPin for Flex<'d, T> {
+        fn is_set_high(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_high())
+        }
+
+        fn is_set_low(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_02::digital::v2::ToggleableOutputPin for Flex<'d, T> {
+        type Error = Infallible;
+        #[inline]
+        fn toggle(&mut self) -> Result<(), Self::Error> {
+            Ok(self.toggle())
+        }
+    }
 }
 
 #[cfg(feature = "unstable-traits")]
@@ -471,4 +563,80 @@ mod eh1 {
             Ok(self.is_set_low())
         }
     }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::ToggleableOutputPin for Output<'d, T> {
+        fn toggle(&mut self) -> Result<(), Self::Error> {
+            Ok(self.toggle())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::ErrorType for OutputOpenDrain<'d, T> {
+        type Error = Infallible;
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::OutputPin for OutputOpenDrain<'d, T> {
+        fn set_high(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_high())
+        }
+
+        fn set_low(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::StatefulOutputPin for OutputOpenDrain<'d, T> {
+        fn is_set_high(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_high())
+        }
+
+        fn is_set_low(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::ToggleableOutputPin for OutputOpenDrain<'d, T> {
+        fn toggle(&mut self) -> Result<(), Self::Error> {
+            Ok(self.toggle())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::ErrorType for Flex<'d, T> {
+        type Error = Infallible;
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::InputPin for Flex<'d, T> {
+        fn is_high(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_high())
+        }
+
+        fn is_low(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::OutputPin for Flex<'d, T> {
+        fn set_high(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_high())
+        }
+
+        fn set_low(&mut self) -> Result<(), Self::Error> {
+            Ok(self.set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::StatefulOutputPin for Flex<'d, T> {
+        fn is_set_high(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_high())
+        }
+
+        fn is_set_low(&self) -> Result<bool, Self::Error> {
+            Ok(self.is_set_low())
+        }
+    }
+
+    impl<'d, T: Pin> embedded_hal_1::digital::blocking::ToggleableOutputPin for Flex<'d, T> {
+        fn toggle(&mut self) -> Result<(), Self::Error> {
+            Ok(self.toggle())
+        }
+    }
 }
diff --git a/tests/rp/.cargo/config.toml b/tests/rp/.cargo/config.toml
new file mode 100644
index 000000000..0330025e4
--- /dev/null
+++ b/tests/rp/.cargo/config.toml
@@ -0,0 +1,20 @@
+[unstable]
+build-std = ["core"]
+build-std-features = ["panic_immediate_abort"]
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+#runner = "teleprobe client run --target bluepill-stm32f103c8 --elf"
+runner = "teleprobe local run --chip RP2040 --elf"
+
+rustflags = [
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+  "-C", "inline-threshold=5",
+  "-C", "no-vectorize-loops",
+]
+
+[build]
+target = "thumbv6m-none-eabi"
+
+[env]
+DEFMT_LOG = "trace"
diff --git a/tests/rp/Cargo.toml b/tests/rp/Cargo.toml
new file mode 100644
index 000000000..b3067fffd
--- /dev/null
+++ b/tests/rp/Cargo.toml
@@ -0,0 +1,48 @@
+[package]
+edition = "2021"
+name = "embassy-rp-tests"
+version = "0.1.0"
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt"] }
+embassy-rp = { version = "0.1.0", path = "../../embassy-rp", features = ["nightly", "defmt", "unstable-pac", "unstable-traits"]  }
+
+defmt = "0.3.0"
+defmt-rtt = "0.3.0"
+
+cortex-m = "0.7.3"
+cortex-m-rt = "0.7.0"
+embedded-hal = "0.2.6"
+embedded-hal-1 = { package = "embedded-hal", version = "1.0.0-alpha.8" }
+embedded-hal-async = { version = "0.1.0-alpha.1" }
+panic-probe = { version = "0.3.0", features = ["print-defmt"] }
+
+[profile.dev]
+debug = 2
+debug-assertions = true
+opt-level = 's'
+overflow-checks = true
+
+[profile.release]
+codegen-units = 1
+debug = 2
+debug-assertions = false
+incremental = false
+lto = "fat"
+opt-level = 's'
+overflow-checks = false
+
+# do not optimize proc-macro crates = faster builds from scratch
+[profile.dev.build-override]
+codegen-units = 8
+debug = false
+debug-assertions = false
+opt-level = 0
+overflow-checks = false
+
+[profile.release.build-override]
+codegen-units = 8
+debug = false
+debug-assertions = false
+opt-level = 0
+overflow-checks = false
diff --git a/tests/rp/build.rs b/tests/rp/build.rs
new file mode 100644
index 000000000..6f4872249
--- /dev/null
+++ b/tests/rp/build.rs
@@ -0,0 +1,16 @@
+use std::error::Error;
+use std::path::PathBuf;
+use std::{env, fs};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let out = PathBuf::from(env::var("OUT_DIR").unwrap());
+    fs::write(out.join("link_ram.x"), include_bytes!("link_ram.x")).unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+    println!("cargo:rerun-if-changed=link_ram.x");
+
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink_ram.x");
+    println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+
+    Ok(())
+}
diff --git a/tests/rp/link_ram.x b/tests/rp/link_ram.x
new file mode 100644
index 000000000..86a11e875
--- /dev/null
+++ b/tests/rp/link_ram.x
@@ -0,0 +1,255 @@
+/* ##### EMBASSY NOTE
+    Originally from https://github.com/rust-embedded/cortex-m-rt/blob/master/link.x.in
+    Adjusted to put everything in RAM
+*/
+
+/* # Developer notes
+
+- Symbols that start with a double underscore (__) are considered "private"
+
+- Symbols that start with a single underscore (_) are considered "semi-public"; they can be
+  overridden in a user linker script, but should not be referred from user code (e.g. `extern "C" {
+  static mut __sbss }`).
+
+- `EXTERN` forces the linker to keep a symbol in the final binary. We use this to make sure a
+  symbol if not dropped if it appears in or near the front of the linker arguments and "it's not
+  needed" by any of the preceding objects (linker arguments)
+
+- `PROVIDE` is used to provide default values that can be overridden by a user linker script
+
+- On alignment: it's important for correctness that the VMA boundaries of both .bss and .data *and*
+  the LMA of .data are all 4-byte aligned. These alignments are assumed by the RAM initialization
+  routine. There's also a second benefit: 4-byte aligned boundaries means that you won't see
+  "Address (..) is out of bounds" in the disassembly produced by `objdump`.
+*/
+
+/* Provides information about the memory layout of the device */
+MEMORY {
+    RAM   : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+/* # Entry point = reset vector */
+EXTERN(__RESET_VECTOR);
+EXTERN(Reset);
+ENTRY(Reset);
+
+/* # Exception vectors */
+/* This is effectively weak aliasing at the linker level */
+/* The user can override any of these aliases by defining the corresponding symbol themselves (cf.
+   the `exception!` macro) */
+EXTERN(__EXCEPTIONS); /* depends on all the these PROVIDED symbols */
+
+EXTERN(DefaultHandler);
+
+PROVIDE(NonMaskableInt = DefaultHandler);
+EXTERN(HardFaultTrampoline);
+PROVIDE(MemoryManagement = DefaultHandler);
+PROVIDE(BusFault = DefaultHandler);
+PROVIDE(UsageFault = DefaultHandler);
+PROVIDE(SecureFault = DefaultHandler);
+PROVIDE(SVCall = DefaultHandler);
+PROVIDE(DebugMonitor = DefaultHandler);
+PROVIDE(PendSV = DefaultHandler);
+PROVIDE(SysTick = DefaultHandler);
+
+PROVIDE(DefaultHandler = DefaultHandler_);
+PROVIDE(HardFault = HardFault_);
+
+/* # Interrupt vectors */
+EXTERN(__INTERRUPTS); /* `static` variable similar to `__EXCEPTIONS` */
+
+/* # Pre-initialization function */
+/* If the user overrides this using the `pre_init!` macro or by creating a `__pre_init` function,
+   then the function this points to will be called before the RAM is initialized. */
+PROVIDE(__pre_init = DefaultPreInit);
+
+/* # Sections */
+SECTIONS
+{
+  PROVIDE(_stack_start = ORIGIN(RAM) + LENGTH(RAM));
+
+  /* ## Sections in RAM */
+  /* ### Vector table */
+  .vector_table ORIGIN(RAM) :
+  {
+    /* Initial Stack Pointer (SP) value */
+    LONG(_stack_start);
+
+    /* Reset vector */
+    KEEP(*(.vector_table.reset_vector)); /* this is the `__RESET_VECTOR` symbol */
+    __reset_vector = .;
+
+    /* Exceptions */
+    KEEP(*(.vector_table.exceptions)); /* this is the `__EXCEPTIONS` symbol */
+    __eexceptions = .;
+
+    /* Device specific interrupts */
+    KEEP(*(.vector_table.interrupts)); /* this is the `__INTERRUPTS` symbol */
+  } > RAM
+
+  PROVIDE(_stext = ADDR(.vector_table) + SIZEOF(.vector_table));
+
+  /* ### .text */
+  .text _stext :
+  {
+    __stext = .;
+    *(.Reset);
+
+    *(.text .text.*);
+
+    /* The HardFaultTrampoline uses the `b` instruction to enter `HardFault`,
+       so must be placed close to it. */
+    *(.HardFaultTrampoline);
+    *(.HardFault.*);
+
+    . = ALIGN(4); /* Pad .text to the alignment to workaround overlapping load section bug in old lld */
+    __etext = .;
+  } > RAM
+
+  /* ### .rodata */
+  .rodata : ALIGN(4)
+  {
+    . = ALIGN(4);
+    __srodata = .;
+    *(.rodata .rodata.*);
+
+    /* 4-byte align the end (VMA) of this section.
+       This is required by LLD to ensure the LMA of the following .data
+       section will have the correct alignment. */
+    . = ALIGN(4);
+    __erodata = .;
+  } > RAM
+
+  /* ## Sections in RAM */
+  /* ### .data */
+  .data : ALIGN(4)
+  {
+    . = ALIGN(4);
+    __sdata = .;
+    __edata = .;
+    *(.data .data.*);
+    . = ALIGN(4); /* 4-byte align the end (VMA) of this section */
+  } > RAM
+  /* Allow sections from user `memory.x` injected using `INSERT AFTER .data` to
+   * use the .data loading mechanism by pushing __edata. Note: do not change
+   * output region or load region in those user sections! */
+  . = ALIGN(4);
+
+  /* LMA of .data */
+  __sidata = LOADADDR(.data);
+
+  /* ### .gnu.sgstubs
+     This section contains the TrustZone-M veneers put there by the Arm GNU linker. */
+  /* Security Attribution Unit blocks must be 32 bytes aligned. */
+  /* Note that this pads the RAM usage to 32 byte alignment. */
+  .gnu.sgstubs : ALIGN(32)
+  {
+    . = ALIGN(32);
+    __veneer_base = .;
+    *(.gnu.sgstubs*)
+    . = ALIGN(32);
+    __veneer_limit = .;
+  } > RAM
+
+  /* ### .bss */
+  .bss (NOLOAD) : ALIGN(4)
+  {
+    . = ALIGN(4);
+    __sbss = .;
+    *(.bss .bss.*);
+    *(COMMON); /* Uninitialized C statics */
+    . = ALIGN(4); /* 4-byte align the end (VMA) of this section */
+  } > RAM
+  /* Allow sections from user `memory.x` injected using `INSERT AFTER .bss` to
+   * use the .bss zeroing mechanism by pushing __ebss. Note: do not change
+   * output region or load region in those user sections! */
+  . = ALIGN(4);
+  __ebss = .;
+
+  /* ### .uninit */
+  .uninit (NOLOAD) : ALIGN(4)
+  {
+    . = ALIGN(4);
+    __suninit = .;
+    *(.uninit .uninit.*);
+    . = ALIGN(4);
+    __euninit = .;
+  } > RAM
+
+  /* Place the heap right after `.uninit` in RAM */
+  PROVIDE(__sheap = __euninit);
+
+  /* ## .got */
+  /* Dynamic relocations are unsupported. This section is only used to detect relocatable code in
+     the input files and raise an error if relocatable code is found */
+  .got (NOLOAD) :
+  {
+    KEEP(*(.got .got.*));
+  }
+
+  /* ## Discarded sections */
+  /DISCARD/ :
+  {
+    /* Unused exception related info that only wastes space */
+    *(.ARM.exidx);
+    *(.ARM.exidx.*);
+    *(.ARM.extab.*);
+  }
+}
+
+/* Do not exceed this mark in the error messages below                                    | */
+/* # Alignment checks */
+ASSERT(ORIGIN(RAM) % 4 == 0, "
+ERROR(cortex-m-rt): the start of the RAM region must be 4-byte aligned");
+
+ASSERT(__sdata % 4 == 0 && __edata % 4 == 0, "
+BUG(cortex-m-rt): .data is not 4-byte aligned");
+
+ASSERT(__sidata % 4 == 0, "
+BUG(cortex-m-rt): the LMA of .data is not 4-byte aligned");
+
+ASSERT(__sbss % 4 == 0 && __ebss % 4 == 0, "
+BUG(cortex-m-rt): .bss is not 4-byte aligned");
+
+ASSERT(__sheap % 4 == 0, "
+BUG(cortex-m-rt): start of .heap is not 4-byte aligned");
+
+/* # Position checks */
+
+/* ## .vector_table */
+ASSERT(__reset_vector == ADDR(.vector_table) + 0x8, "
+BUG(cortex-m-rt): the reset vector is missing");
+
+ASSERT(__eexceptions == ADDR(.vector_table) + 0x40, "
+BUG(cortex-m-rt): the exception vectors are missing");
+
+ASSERT(SIZEOF(.vector_table) > 0x40, "
+ERROR(cortex-m-rt): The interrupt vectors are missing.
+Possible solutions, from most likely to less likely:
+- Link to a svd2rust generated device crate
+- Check that you actually use the device/hal/bsp crate in your code
+- Disable the 'device' feature of cortex-m-rt to build a generic application (a dependency
+may be enabling it)
+- Supply the interrupt handlers yourself. Check the documentation for details.");
+
+/* ## .text */
+ASSERT(ADDR(.vector_table) + SIZEOF(.vector_table) <= _stext, "
+ERROR(cortex-m-rt): The .text section can't be placed inside the .vector_table section
+Set _stext to an address greater than the end of .vector_table (See output of `nm`)");
+
+ASSERT(_stext + SIZEOF(.text) < ORIGIN(RAM) + LENGTH(RAM), "
+ERROR(cortex-m-rt): The .text section must be placed inside the RAM memory.
+Set _stext to an address smaller than 'ORIGIN(RAM) + LENGTH(RAM)'");
+
+/* # Other checks */
+ASSERT(SIZEOF(.got) == 0, "
+ERROR(cortex-m-rt): .got section detected in the input object files
+Dynamic relocations are not supported. If you are linking to C code compiled using
+the 'cc' crate then modify your build script to compile the C code _without_
+the -fPIC flag. See the documentation of the `cc::Build.pic` method for details.");
+/* Do not exceed this mark in the error messages above                                    | */
+
+
+/* Provides weak aliases (cf. PROVIDED) for device specific interrupt handlers */
+/* This will usually be provided by a device crate generated using svd2rust (see `device.x`) */
+INCLUDE device.x
\ No newline at end of file
diff --git a/tests/rp/src/bin/gpio.rs b/tests/rp/src/bin/gpio.rs
new file mode 100644
index 000000000..0be9d9f24
--- /dev/null
+++ b/tests/rp/src/bin/gpio.rs
@@ -0,0 +1,192 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::{assert, *};
+use embassy::executor::Spawner;
+use embassy_rp::gpio::{Flex, Input, Level, Output, OutputOpenDrain, Pull};
+use embassy_rp::Peripherals;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let (mut a, mut b) = (p.PIN_0, p.PIN_1);
+
+    // Test initial output
+    {
+        let b = Input::new(&mut b, Pull::None);
+
+        {
+            let _a = Output::new(&mut a, Level::Low);
+            delay();
+            assert!(b.is_low());
+        }
+        {
+            let _a = Output::new(&mut a, Level::High);
+            delay();
+            assert!(b.is_high());
+        }
+    }
+
+    // Test input no pull
+    {
+        let b = Input::new(&mut b, Pull::None);
+        // no pull, the status is undefined
+
+        let mut a = Output::new(&mut a, Level::Low);
+        delay();
+        assert!(b.is_low());
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
+    // Test input pulldown
+    {
+        let b = Input::new(&mut b, Pull::Down);
+        delay();
+        assert!(b.is_low());
+
+        let mut a = Output::new(&mut a, Level::Low);
+        delay();
+        assert!(b.is_low());
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
+    // Test input pullup
+    {
+        let b = Input::new(&mut b, Pull::Up);
+        delay();
+        assert!(b.is_high());
+
+        let mut a = Output::new(&mut a, Level::Low);
+        delay();
+        assert!(b.is_low());
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
+    // OUTPUT OPEN DRAIN
+    {
+        let mut b = OutputOpenDrain::new(&mut b, Level::High);
+        let mut a = Flex::new(&mut a);
+        a.set_as_input();
+
+        // When an OutputOpenDrain is high, it doesn't drive the pin.
+        a.set_pull(Pull::Up);
+        delay();
+        assert!(a.is_high());
+        a.set_pull(Pull::Down);
+        delay();
+        assert!(a.is_low());
+
+        b.set_low();
+
+        // When an OutputOpenDrain is low, it drives the pin low.
+        a.set_pull(Pull::Up);
+        delay();
+        assert!(a.is_low());
+        a.set_pull(Pull::Down);
+        delay();
+        assert!(a.is_low());
+
+        b.set_high();
+
+        a.set_pull(Pull::Up);
+        delay();
+        assert!(a.is_high());
+        a.set_pull(Pull::Down);
+        delay();
+        assert!(a.is_low());
+    }
+
+    // FLEX
+    // Test initial output
+    {
+        //Flex pin configured as input
+        let mut b = Flex::new(&mut b);
+        b.set_as_input();
+
+        {
+            //Flex pin configured as output
+            let mut a = Flex::new(&mut a); //Flex pin configured as output
+            a.set_low(); // Pin state must be set before configuring the pin, thus we avoid unknown state
+            a.set_as_output();
+            delay();
+            assert!(b.is_low());
+        }
+        {
+            //Flex pin configured as output
+            let mut a = Flex::new(&mut a);
+            a.set_high();
+            a.set_as_output();
+
+            delay();
+            assert!(b.is_high());
+        }
+    }
+
+    // Test input no pull
+    {
+        let mut b = Flex::new(&mut b);
+        b.set_as_input(); // no pull by default.
+
+        let mut a = Flex::new(&mut a);
+        a.set_low();
+        a.set_as_output();
+
+        delay();
+        assert!(b.is_low());
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
+    // Test input pulldown
+    {
+        let mut b = Flex::new(&mut b);
+        b.set_as_input();
+        b.set_pull(Pull::Down);
+        delay();
+        assert!(b.is_low());
+
+        let mut a = Flex::new(&mut a);
+        a.set_low();
+        a.set_as_output();
+        delay();
+        assert!(b.is_low());
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
+    // Test input pullup
+    {
+        let mut b = Flex::new(&mut b);
+        b.set_as_input();
+        b.set_pull(Pull::Up);
+        delay();
+        assert!(b.is_high());
+
+        let mut a = Flex::new(&mut a);
+        a.set_high();
+        a.set_as_output();
+        delay();
+        assert!(b.is_high());
+        a.set_low();
+        delay();
+        assert!(b.is_low());
+    }
+
+    info!("Test OK");
+    cortex_m::asm::bkpt();
+}
+
+fn delay() {
+    cortex_m::asm::delay(10000);
+}