libmctp: Initial commit

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Cargo.toml

diff --git a/Cargo.toml b/Cargo.toml
index caeae02..99543d9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,6 +29,7 @@
 p256 = { version = "0.5.0" , default-features = false, features = ["arithmetic", "ecdsa", "ecdsa-core"] }
 subtle = { version = "2.3.0", default-features = false, features = ["i128"] }
 generic-array = { version = "0.14.3" }
+libmctp = { version = "0.1.0" }
 
 # We need to override this to allow builds for targets that don't support atomics.
 # Once a version newer then 0.4.11 is released we can update to use that.

examples/libmctp.rs

diff --git a/examples/libmctp.rs b/examples/libmctp.rs
new file mode 100644
index 0000000..8623665
--- /dev/null
+++ b/examples/libmctp.rs
@@ -0,0 +1,105 @@
+#![no_std]
+/// This is a example of a MCTP master device
+use libmctp::smbus::{MCTPSMBusContext, VendorIDFormat};
+use libtock::i2c_master::I2cBuffer;
+use libtock::println;
+use libtock::result::TockResult;
+use libtock::syscalls;
+
+libtock_core::stack_size! {0x800}
+
+// The address of this device
+const MY_ID: u8 = 0x23;
+const DEST_ID: u8 = 0x10;
+// Support vendor defined protocol 0x7E
+const MSG_TYPES: [u8; 1] = [0x7E];
+// Specify a PCI vendor ID that we support
+const VENDOR_IDS: [libmctp::smbus::VendorIDFormat; 1] = [VendorIDFormat {
+    // PCI Vendor ID
+    format: 0x00,
+    // PCI VID
+    data: 0x1414,
+    // Extra data
+    numeric_value: 4,
+}];
+
+#[libtock::main]
+async fn main() -> TockResult<()> {
+    let mut drivers = libtock::retrieve_drivers()?;
+    drivers.console.create_console();
+    println!("Starting libmctp example");
+    let i2c_driver = drivers.i2c.init_driver()?;
+
+    // Check that I2C exists
+    if i2c_driver.check_present().is_err() {
+        println!("No I2C device, yielding");
+        loop {
+            unsafe { syscalls::raw::yieldk() };
+        }
+    }
+    println!("Found the I2C device");
+
+    println!("Setting callback");
+    let mut callback = |_, _| {
+        println!("I2C Callback");
+    };
+
+    let _subscription = i2c_driver.subscribe(&mut callback)?;
+    println!("Creating MCTP SMBus Context");
+    let ctx = MCTPSMBusContext::new(MY_ID, &MSG_TYPES, &VENDOR_IDS);
+
+    let mut buf: [u8; 32] = [0; 32];
+
+    println!("Creating the request");
+    let len = ctx
+        .get_request()
+        .get_vendor_defined_message_support(0xB, 0, &mut buf);
+
+    println!("Creating master write buffer");
+    let mut master_write_buffer = I2cBuffer::default();
+    // Skip the first byte, as that is the destination address
+    for (i, d) in buf[1..].iter().enumerate() {
+        master_write_buffer[i] = *d;
+    }
+    let dest_buffer = i2c_driver.init_buffer(&mut master_write_buffer)?;
+    println!("  done");
+
+    let _ = i2c_driver.write(DEST_ID as usize, len.unwrap());
+
+    unsafe { syscalls::raw::yieldk() };
+
+    // Read 4 bytes for the SMBus header
+    let _ = i2c_driver.read(DEST_ID as usize, 4);
+
+    unsafe { syscalls::raw::yieldk() };
+
+    // Copy into a temp buffer
+    let mut temp_buffer = [0; libtock::hmac::DEST_BUFFER_SIZE];
+    dest_buffer.read_bytes(&mut temp_buffer[1..4]);
+
+    // Determine the full length
+    let bytes = ctx.get_length(&temp_buffer).unwrap();
+
+    // Read the full packet. The slave will re-send the data, so do
+    // a full read
+    let _ = i2c_driver.read(DEST_ID as usize, bytes - 1);
+
+    unsafe { syscalls::raw::yieldk() };
+
+    // Copy in the full packet, with space for the destination address
+    dest_buffer.read_bytes(&mut temp_buffer[1..bytes - 1]);
+
+    // Set the destination address as this isn't filled in the buffer from
+    // the kernel
+    temp_buffer[0] = DEST_ID << 1;
+
+    // Decode the response
+    let ret = ctx.decode_packet(&temp_buffer[0..bytes]);
+
+    // Print the outcome of the decode
+    println!("ret: {:?}", ret);
+
+    loop {
+        unsafe { syscalls::raw::yieldk() };
+    }
+}