From 0291bf41d28533c4731991dad25a05c712cede78 Mon Sep 17 00:00:00 2001
From: Levi Pearson <levipearson@gmail.com>
Date: Tue, 7 Jul 2020 23:46:22 -0600
Subject: [PATCH] Add cargo embed support, including rtt printing & panic logs

---
 Cargo.toml  |  1 +
 Embed.toml  | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/main.rs | 20 +++++++++++++++++++-
 3 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 Embed.toml

diff --git a/Cargo.toml b/Cargo.toml
index a551fd4..a6d3511 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,6 +19,7 @@ panic-halt = "0.2.0"
 #panic-persist = "0.2.1"
 embedded-hal = "0.2.3"
 nb = "0.1.2"
+rtt-target = { version = "0.2.0", features = ["cortex-m"] }
 
 [dependencies.stm32f1]
 version = "0.10.0"
diff --git a/Embed.toml b/Embed.toml
new file mode 100644
index 0000000..8a45ee4
--- /dev/null
+++ b/Embed.toml
@@ -0,0 +1,50 @@
+[default.probe]
+# USB vendor ID
+# usb_vid = "1337"
+# USB product ID
+# usb_pid = "1337"
+# Serial number
+# serial = "12345678"
+# The protocol to be used for communicating with the target.
+protocol = "Swd"
+# The speed in kHz of the data link to the target.
+# speed = 1337
+
+[default.flashing]
+# Whether or not the target should be flashed.
+enabled = true
+# Whether or not the target should be halted after flashing.
+halt_afterwards = false
+# Whether or not bytes erased but not rewritten with data from the ELF
+# should be restored with their contents before erasing.
+restore_unwritten_bytes = false
+# The path where an SVG of the assembled flash layout should be written to.
+# flash_layout_output_path = "out.svg"
+
+[default.general]
+# The chip name of the chip to be debugged.
+chip = "stm32f103C8"
+# A list of chip descriptions to be loaded during runtime.
+chip_descriptions = []
+# The default log level to be used.
+log_level = "Warn"
+
+[default.rtt]
+# Whether or not an RTTUI should be opened after flashing.
+# This is exclusive and cannot be used with GDB at the moment.
+enabled = true
+# A list of channel associations to be displayed. If left empty, all channels are displayed.
+channels = [
+    # { up = 0, down = 0, name = "name" }
+]
+# The duration in ms for which the logger should retry to attach to RTT.
+timeout = 3000
+# Whether timestamps in the RTTUI are enabled
+show_timestamps = true
+
+[default.gdb]
+# Whether or not a GDB server should be opened after flashing.
+# This is exclusive and cannot be used with RTT at the moment.
+enabled = false
+# The connection string in host:port format wher the GDB server will open a socket.
+# gdb_connection_string
diff --git a/src/main.rs b/src/main.rs
index 7b224e7..504351c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,7 +9,9 @@
 #![no_std]
 #![no_main]
 
-use panic_halt as _;
+//use panic_halt as _;
+use core::panic::PanicInfo;
+use rtt_target::{rprintln, rtt_init_print};
 
 use nb::block;
 
@@ -23,6 +25,8 @@ use embedded_hal::digital::v2::OutputPin;
 
 #[entry]
 fn main() -> ! {
+    // Init buffers for debug printing
+    rtt_init_print!();
     // Get access to the core peripherals from the cortex-m crate
     let cp = cortex_m::Peripherals::take().unwrap();
     // Get access to the device specific peripherals from the peripheral access crate
@@ -46,11 +50,25 @@ fn main() -> ! {
     // Configure the syst timer to trigger an update every second
     let mut timer = Timer::syst(cp.SYST, &clocks).start_count_down(1.hz());
 
+    rprintln!("Hello, Rust!");
     // Wait for the timer to trigger an update and change the state of the LED
+    let mut i = 0;
     loop {
         block!(timer.wait()).unwrap();
         led.set_high().unwrap();
         block!(timer.wait()).unwrap();
         led.set_low().unwrap();
+        i += 1;
+        rprintln!("Hello again; I have blinked {} times.", i);
+        if i == 10 {
+            panic!("Yow, 10 times is enough!");
+        }
     }
 }
+
+#[inline(never)]
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    rprintln!("{}", info);
+    loop {} // You might need a compiler fence in here.
+}