aarch64: add crate bcm2837, implement GPIO

crate/bcm2837/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "bcm2837"
+version = "0.1.0"
+authors = ["equation314 <equation618@gmail.com>"]
+
+[dependencies]
+volatile = "0.2.4"

crate/bcm2837/src/asm.rs

@@ -0,0 +1,10 @@
+//! utility assembly instructions
+
+/// delay for some clocks
+#[inline]
+pub unsafe fn delay(clock: u32) {
+    #[cfg(target_arch = "aarch64")]
+    asm!("1: subs x0, x0, #1; bne 1b;"
+        :: "{x0}"(clock)
+        :: "volatile");
+}

crate/bcm2837/src/gpio.rs

@@ -0,0 +1,159 @@
+use super::IO_BASE;
+use super::asm::delay;
+use core::marker::PhantomData;
+use volatile::{ReadOnly, Volatile, WriteOnly};
+
+/// The base address of the `GPIO` registers.
+const GPIO_BASE: usize = IO_BASE + 0x200000;
+
+/// An alternative GPIO function.
+#[repr(u8)]
+pub enum Function {
+    Input = 0b000,
+    Output = 0b001,
+    Alt0 = 0b100,
+    Alt1 = 0b101,
+    Alt2 = 0b110,
+    Alt3 = 0b111,
+    Alt4 = 0b011,
+    Alt5 = 0b010,
+}
+
+#[repr(C)]
+#[allow(non_snake_case)]
+struct Registers {
+    FSEL: [Volatile<u32>; 6],
+    __reserved0: u32,
+    SET: [WriteOnly<u32>; 2],
+    __reserved1: u32,
+    CLR: [WriteOnly<u32>; 2],
+    __reserved2: u32,
+    LEV: [ReadOnly<u32>; 2],
+    __reserved3: u32,
+    EDS: [Volatile<u32>; 2],
+    __reserved4: u32,
+    REN: [Volatile<u32>; 2],
+    __reserved5: u32,
+    FEN: [Volatile<u32>; 2],
+    __reserved6: u32,
+    HEN: [Volatile<u32>; 2],
+    __reserved7: u32,
+    LEN: [Volatile<u32>; 2],
+    __reserved8: u32,
+    AREN: [Volatile<u32>; 2],
+    __reserved9: u32,
+    AFEN: [Volatile<u32>; 2],
+    __reserved10: u32,
+    PUD: Volatile<u32>,
+    PUDCLK: [Volatile<u32>; 2],
+}
+
+/// Possible states for a GPIO pin.
+pub enum Uninitialized {}
+pub enum Input {}
+pub enum Output {}
+pub enum Alt {}
+
+/// A GPIO pin in state `State`.
+///
+/// The `State` generic always corresponds to an uninstantiatable type that is
+/// use solely to mark and track the state of a given GPIO pin. A `Gpio`
+/// structure starts in the `Uninitialized` state and must be transitions into
+/// one of `Input`, `Output`, or `Alt` via the `into_input`, `into_output`, and
+/// `into_alt` methods before it can be used.
+pub struct Gpio<State> {
+    pin: u8,
+    registers: &'static mut Registers,
+    _state: PhantomData<State>,
+}
+
+impl<T> Gpio<T> {
+    /// Transitions `self` to state `S`, consuming `self` and returning a new
+    /// `Gpio` instance in state `S`. This method should _never_ be exposed to
+    /// the public!
+    #[inline(always)]
+    fn transition<S>(self) -> Gpio<S> {
+        Gpio {
+            pin: self.pin,
+            registers: self.registers,
+            _state: PhantomData,
+        }
+    }
+
+    /// Set the Gpio pull-up/pull-down state for values in `pin_value`
+    pub fn set_gpio_pd(&mut self, pud_value: u8) {
+        unsafe {
+            let index = if self.pin >= 32 { 1 } else { 0 };
+
+            self.registers.PUD.write(pud_value as u32);
+            delay(150);
+            self.registers.PUDCLK[index as usize].write((1 << self.pin) as u32);
+            delay(150);
+            self.registers.PUD.write(0);
+            self.registers.PUDCLK[index as usize].write(0);
+        }
+    }
+}
+
+impl Gpio<Uninitialized> {
+    /// Returns a new `GPIO` structure for pin number `pin`.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `pin` > `53`.
+    pub fn new(pin: u8) -> Gpio<Uninitialized> {
+        if pin > 53 {
+            panic!("Gpio::new(): pin {} exceeds maximum of 53", pin);
+        }
+
+        Gpio {
+            registers: unsafe { &mut *(GPIO_BASE as *mut Registers) },
+            pin: pin,
+            _state: PhantomData,
+        }
+    }
+
+    /// Enables the alternative function `function` for `self`. Consumes self
+    /// and returns a `Gpio` structure in the `Alt` state.
+    pub fn into_alt(self, function: Function) -> Gpio<Alt> {
+        self.registers.FSEL[(self.pin / 10) as usize]
+            .write((function as u32) << (3 * (self.pin % 10)));
+        self.transition()
+    }
+
+    /// Sets this pin to be an _output_ pin. Consumes self and returns a `Gpio`
+    /// structure in the `Output` state.
+    pub fn into_output(self) -> Gpio<Output> {
+        self.into_alt(Function::Output).transition()
+    }
+
+    /// Sets this pin to be an _input_ pin. Consumes self and returns a `Gpio`
+    /// structure in the `Input` state.
+    pub fn into_input(self) -> Gpio<Input> {
+        self.into_alt(Function::Input).transition()
+    }
+}
+
+impl Gpio<Output> {
+    /// Sets (turns on) the pin.
+    pub fn set(&mut self) {
+        let index = if self.pin >= 32 { 1 } else { 0 };
+        self.registers.SET[index as usize].write(1 << (self.pin - index * 32));
+    }
+
+    /// Clears (turns off) the pin.
+    pub fn clear(&mut self) {
+        let index = if self.pin >= 32 { 1 } else { 0 };
+        self.registers.CLR[index as usize].write(1 << (self.pin - index * 32));
+    }
+}
+
+impl Gpio<Input> {
+    /// Reads the pin's value. Returns `true` if the level is high and `false`
+    /// if the level is low.
+    pub fn level(&mut self) -> bool {
+        let index = if self.pin >= 32 { 1 } else { 0 };
+        let high = 1 << (self.pin - index * 32);
+        (self.registers.LEV[index as usize].read() & high) == high
+    }
+}

crate/bcm2837/src/lib.rs

@@ -0,0 +1,11 @@
+#![no_std]
+#![feature(asm)]
+
+extern crate volatile;
+
+mod asm;
+
+pub mod gpio;
+pub mod mini_uart;
+
+pub const IO_BASE: usize = 0x3F000000;

crate/bcm2837/src/mini_uart.rs

@@ -0,0 +1 @@
+use super::IO_BASE;

kernel/Cargo.lock

@@ -7,6 +7,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "bbl"
 version = "0.1.0"
 
+[[package]]
+name = "bcm2837"
+version = "0.1.0"
+dependencies = [
+ "volatile 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "bit-allocator"
 version = "0.1.0"
@@ -211,6 +218,7 @@ name = "ucore"
 version = "0.1.0"
 dependencies = [
  "bbl 0.1.0",
+ "bcm2837 0.1.0",
  "bit-allocator 0.1.0",
  "bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -227,7 +235,7 @@ dependencies = [
  "uart_16550 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ucore-memory 0.1.0",
  "ucore-process 0.1.0",
- "volatile 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "volatile 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "x86_64 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "xmas-elf 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -265,7 +273,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "volatile"
-version = "0.1.0"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -344,7 +352,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum usize_conversions 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f70329e2cbe45d6c97a5112daad40c34cd9a4e18edb5a2a18fefeb584d8d25e5"
 "checksum ux 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "53d8df5dd8d07fedccd202de1887d94481fadaea3db70479f459e8163a1fab41"
 "checksum version_check 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7716c242968ee87e5542f8021178248f267f295a5c4803beae8b8b7fd9bc6051"
-"checksum volatile 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "37c5d76c0f40ba4f8ac10ec4717d4e98ce3e58c5607eea36e9464226fc5e0a95"
+"checksum volatile 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "54d4343a2df2d65144a874f95950754ee7b7e8594f6027aae8c7d0f4858a3fe8"
 "checksum winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "773ef9dcc5f24b7d850d0ff101e542ff24c3b090a9768e03ff889fdef41f00fd"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

kernel/Cargo.toml

@@ -25,7 +25,7 @@ once = "0.3.3"
 xmas-elf = "0.6"
 bitflags = "1.0"
 bit_field = "0.9.0"
-volatile = "0.1.0"
+volatile = "0.2.4"
 linked_list_allocator = "0.6"
 lazy_static = { version = "1.0.0", features = ["spin_no_std"] }
 bit-allocator = { path = "../crate/bit-allocator" }
@@ -43,6 +43,9 @@ uart_16550 = "0.1"
 riscv = { path = "../crate/riscv" }
 bbl = { path = "../crate/bbl" }
 
+[target.'cfg(target_arch = "aarch64")'.dependencies]
+bcm2837 = { path = "../crate/bcm2837" }
+
 [package.metadata.bootimage]
 default-target = "x86_64-blog_os.json"
 output = "target/x86_64-blog_os/bootimage.bin"

kernel/src/arch/aarch64/board/raspi3/mod.rs

@@ -1,5 +1,9 @@
 //! Raspberry PI 3 Model B/B+
 
+extern crate bcm2837;
+
 pub fn init() {
     // TODO
+    bcm2837::gpio::Gpio::new(14).set_gpio_pd(0);
+    bcm2837::gpio::Gpio::new(15).set_gpio_pd(0);
 }

kernel/src/arch/aarch64/mod.rs

@@ -11,8 +11,11 @@ pub mod board;
 
 /// TODO
 /// The entry point of kernel
-#[no_mangle]    // don't mangle the name of this function
-pub extern fn rust_main() -> ! {
+#[no_mangle] // don't mangle the name of this function
+pub extern "C" fn rust_main() -> ! {
+    // Init board.
+    board::init();
+
     println!("Hello ARM64!");
 
     // First init log mod, so that we can print log info.
@@ -24,8 +27,6 @@ pub extern fn rust_main() -> ! {
     // Now heap is available
     // timer::init();
 
-    // Init board.
-    board::init();
     ::kmain();
 }