Merge #391c-m-rt-v0.7.1

391: Merge cortex-m-rt into this repository r=thejpster a=adamgreig

This PR merges the cortex-m-rt repository (with history) into this repo, inside the `cortex-m-rt` folder which is added to the workspace. The main advantage is easier combined testing of cortex-m with cortex-m-rt (including on-hardware tests e.g. #355), and in the future easier changes across the two projects.

The MSRV of cortex-m-rt is bumped 1.39 -> 1.40 to align it with cortex-m itself.

I've updated the CI to run the same tests and checks as before, and updated references to the old URL.

If/after this is merged, I propose adding a note to the old repo's README and then archiving it.

An alternative to this technique would be adding all the files in one new commit (not preserving history), if anyone thinks that would be neater.

NB: This PR also adds an inline to ITM to fix a clippy hard error.

For future reference, the git work was:

```
cd cortex-m-rt
git filter-repo --to-subdirectory-filter cortex-m-rt
cd ../cortex-m
git remote add rt ../cortex-m-rt
git fetch rt
git merge --allow-unrelated-histories rt/master
```

Co-authored-by: bors[bot] <bors[bot]@users.noreply.github.com>
Co-authored-by: Jonathan 'theJPster' Pallant <github@thejpster.org.uk>
Co-authored-by: Adam Greig <adam@adamgreig.com>
Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>
Co-authored-by: Jorge Aparicio <jorge@japaric.io>
Co-authored-by: Emil Fresk <emil.fresk@gmail.com>
Co-authored-by: Daniel Egger <daniel@eggers-club.de>
Co-authored-by: Niklas Claesson <nicke.claesson@gmail.com>
Co-authored-by: bors[bot] <26634292+bors[bot]@users.noreply.github.com>
Co-authored-by: Vadim Kaushan <admin@disasm.info>

19 files changed, 460 insertions, 0 deletions

diff --git a/cortex-m-rt/examples/alignment.rs b/cortex-m-rt/examples/alignment.rs
new file mode 100644
index 0000000..4421e69
--- /dev/null
+++ b/cortex-m-rt/examples/alignment.rs
@@ -0,0 +1,33 @@
+//! This is not an example; this is a link-pass test
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use core::ptr;
+
+use rt::entry;
+
+static mut BSS1: u16 = 0;
+static mut BSS2: u8 = 0;
+static mut DATA1: u8 = 1;
+static mut DATA2: u16 = 1;
+static RODATA1: &[u8; 3] = b"012";
+static RODATA2: &[u8; 2] = b"34";
+
+#[entry]
+fn main() -> ! {
+    unsafe {
+        let _bss1 = ptr::read_volatile(&BSS1);
+        let _bss2 = ptr::read_volatile(&BSS2);
+        let _data1 = ptr::read_volatile(&DATA1);
+        let _data2 = ptr::read_volatile(&DATA2);
+        let _rodata1 = ptr::read_volatile(&RODATA1);
+        let _rodata2 = ptr::read_volatile(&RODATA2);
+    }
+
+    loop {}
+}
diff --git a/cortex-m-rt/examples/cfg-static.rs b/cortex-m-rt/examples/cfg-static.rs
new file mode 100644
index 0000000..2ffee13
--- /dev/null
+++ b/cortex-m-rt/examples/cfg-static.rs
@@ -0,0 +1,25 @@
+//! using `#[cfg]` on `static` shouldn't cause compile errors
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::{entry, exception};
+
+#[entry]
+fn main() -> ! {
+    #[cfg(never)]
+    static mut COUNT: u32 = 0;
+
+    loop {}
+}
+
+#[exception]
+fn SysTick() {
+    #[cfg(never)]
+    static mut FOO: u32 = 0;
+}
diff --git a/cortex-m-rt/examples/data_overflow.rs b/cortex-m-rt/examples/data_overflow.rs
new file mode 100644
index 0000000..a84ec12
--- /dev/null
+++ b/cortex-m-rt/examples/data_overflow.rs
@@ -0,0 +1,30 @@
+//! This is not an example; this is a linker overflow detection test
+//! which should fail to link due to .data overflowing FLASH.
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use core::ptr;
+
+use rt::entry;
+
+// This large static array uses most of .rodata
+static RODATA: [u8; 48 * 1024] = [1u8; 48 * 1024];
+
+// This large mutable array causes .data to use the rest of FLASH
+// without also overflowing RAM.
+static mut DATA: [u8; 16 * 1024] = [1u8; 16 * 1024];
+
+#[entry]
+fn main() -> ! {
+    unsafe {
+        let _bigdata = ptr::read_volatile(&RODATA as *const u8);
+        let _bigdata = ptr::read_volatile(&DATA as *const u8);
+    }
+
+    loop {}
+}
diff --git a/cortex-m-rt/examples/device.rs b/cortex-m-rt/examples/device.rs
new file mode 100644
index 0000000..c18b569
--- /dev/null
+++ b/cortex-m-rt/examples/device.rs
@@ -0,0 +1,36 @@
+//! Manually create the interrupts portion of the vector table
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::entry;
+
+#[entry]
+fn main() -> ! {
+    loop {}
+}
+
+// interrupts portion of the vector table
+pub union Vector {
+    handler: unsafe extern "C" fn(),
+    reserved: usize,
+}
+
+extern "C" {
+    fn WWDG();
+    fn PVD();
+}
+
+#[allow(unsafe_code)]
+#[link_section = ".vector_table.interrupts"]
+#[no_mangle]
+pub static __INTERRUPTS: [Vector; 3] = [
+    Vector { handler: WWDG },
+    Vector { reserved: 0 },
+    Vector { handler: PVD },
+];
diff --git a/cortex-m-rt/examples/divergent-default-handler.rs b/cortex-m-rt/examples/divergent-default-handler.rs
new file mode 100644
index 0000000..3290254
--- /dev/null
+++ b/cortex-m-rt/examples/divergent-default-handler.rs
@@ -0,0 +1,18 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception]
+unsafe fn DefaultHandler(_irqn: i16) -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/divergent-exception.rs b/cortex-m-rt/examples/divergent-exception.rs
new file mode 100644
index 0000000..cb2247b
--- /dev/null
+++ b/cortex-m-rt/examples/divergent-exception.rs
@@ -0,0 +1,18 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception]
+fn SysTick() -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/entry-static.rs b/cortex-m-rt/examples/entry-static.rs
new file mode 100644
index 0000000..55e7a89
--- /dev/null
+++ b/cortex-m-rt/examples/entry-static.rs
@@ -0,0 +1,20 @@
+//! `static mut` variables local to the entry point are safe to use
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::entry;
+
+#[entry]
+fn main() -> ! {
+    static mut COUNT: u32 = 0;
+
+    loop {
+        *COUNT += 1;
+    }
+}
diff --git a/cortex-m-rt/examples/main.rs b/cortex-m-rt/examples/main.rs
new file mode 100644
index 0000000..58e3cb4
--- /dev/null
+++ b/cortex-m-rt/examples/main.rs
@@ -0,0 +1,13 @@
+//! Directly plug a `main` symbol instead of using `#[entry]`
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+#[no_mangle]
+pub unsafe extern "C" fn main() -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/minimal.rs b/cortex-m-rt/examples/minimal.rs
new file mode 100644
index 0000000..bd0a6ad
--- /dev/null
+++ b/cortex-m-rt/examples/minimal.rs
@@ -0,0 +1,17 @@
+//! Minimal `cortex-m-rt` based program
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::entry;
+
+// the program entry point
+#[entry]
+fn main() -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/override-exception.rs b/cortex-m-rt/examples/override-exception.rs
new file mode 100644
index 0000000..3190b77
--- /dev/null
+++ b/cortex-m-rt/examples/override-exception.rs
@@ -0,0 +1,29 @@
+//! How to override the hard fault exception handler and the default exception handler
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m;
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use cortex_m::asm;
+use rt::{entry, exception, ExceptionFrame};
+
+#[entry]
+fn main() -> ! {
+    loop {}
+}
+
+#[exception]
+unsafe fn DefaultHandler(_irqn: i16) {
+    asm::bkpt();
+}
+
+#[exception]
+unsafe fn HardFault(_ef: &ExceptionFrame) -> ! {
+    asm::bkpt();
+
+    loop {}
+}
diff --git a/cortex-m-rt/examples/pre_init.rs b/cortex-m-rt/examples/pre_init.rs
new file mode 100644
index 0000000..2c931bb
--- /dev/null
+++ b/cortex-m-rt/examples/pre_init.rs
@@ -0,0 +1,20 @@
+//! `cortex-m-rt` based program with a function run before RAM is initialized.
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::{entry, pre_init};
+
+#[pre_init]
+unsafe fn disable_watchdog() {
+    // Do what you need to disable the watchdog.
+}
+
+#[entry]
+fn main() -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/qemu.rs b/cortex-m-rt/examples/qemu.rs
new file mode 100644
index 0000000..e903404
--- /dev/null
+++ b/cortex-m-rt/examples/qemu.rs
@@ -0,0 +1,28 @@
+// #![feature(stdsimd)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m;
+extern crate cortex_m_rt as rt;
+extern crate cortex_m_semihosting as semihosting;
+
+extern crate panic_halt;
+
+use cortex_m::asm;
+use rt::entry;
+
+#[entry]
+fn main() -> ! {
+    use core::fmt::Write;
+    let x = 42;
+
+    loop {
+        asm::nop();
+
+        // write something through semihosting interface
+        let mut hstdout = semihosting::hio::hstdout().unwrap();
+        write!(hstdout, "x = {}\n", x).unwrap();
+        // exit from qemu
+        semihosting::debug::exit(semihosting::debug::EXIT_SUCCESS);
+    }
+}
diff --git a/cortex-m-rt/examples/state.rs b/cortex-m-rt/examples/state.rs
new file mode 100644
index 0000000..ee6224d
--- /dev/null
+++ b/cortex-m-rt/examples/state.rs
@@ -0,0 +1,24 @@
+//! Preserving state across executions of an exception handler
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt as rt;
+extern crate panic_halt;
+
+use rt::{entry, exception};
+
+#[entry]
+fn main() -> ! {
+    loop {}
+}
+
+// exception handler with state
+#[exception]
+fn SysTick() {
+    static mut STATE: u32 = 0;
+
+    *STATE += 1;
+}
diff --git a/cortex-m-rt/examples/unsafe-default-handler.rs b/cortex-m-rt/examples/unsafe-default-handler.rs
new file mode 100644
index 0000000..a805c12
--- /dev/null
+++ b/cortex-m-rt/examples/unsafe-default-handler.rs
@@ -0,0 +1,16 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception]
+unsafe fn DefaultHandler(_irqn: i16) {}
diff --git a/cortex-m-rt/examples/unsafe-entry.rs b/cortex-m-rt/examples/unsafe-entry.rs
new file mode 100644
index 0000000..9dcbf33
--- /dev/null
+++ b/cortex-m-rt/examples/unsafe-entry.rs
@@ -0,0 +1,13 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::entry;
+
+#[entry]
+unsafe fn foo() -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/unsafe-exception.rs b/cortex-m-rt/examples/unsafe-exception.rs
new file mode 100644
index 0000000..4212610
--- /dev/null
+++ b/cortex-m-rt/examples/unsafe-exception.rs
@@ -0,0 +1,16 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception]
+unsafe fn SysTick() {}
diff --git a/cortex-m-rt/examples/unsafe-hard-fault.rs b/cortex-m-rt/examples/unsafe-hard-fault.rs
new file mode 100644
index 0000000..b1d48f3
--- /dev/null
+++ b/cortex-m-rt/examples/unsafe-hard-fault.rs
@@ -0,0 +1,18 @@
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception, ExceptionFrame};
+
+#[entry]
+fn foo() -> ! {
+    loop {}
+}
+
+#[exception]
+unsafe fn HardFault(_ef: &ExceptionFrame) -> ! {
+    loop {}
+}
diff --git a/cortex-m-rt/examples/unsafety.rs b/cortex-m-rt/examples/unsafety.rs
new file mode 100644
index 0000000..cdb5aca
--- /dev/null
+++ b/cortex-m-rt/examples/unsafety.rs
@@ -0,0 +1,36 @@
+//! Checks that the declared unsafety is respected by the attributes
+
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception, ExceptionFrame};
+
+#[entry]
+unsafe fn main() -> ! {
+    foo();
+
+    loop {}
+}
+
+#[exception]
+unsafe fn DefaultHandler(_irqn: i16) {
+    foo();
+}
+
+#[exception]
+unsafe fn HardFault(_ef: &ExceptionFrame) -> ! {
+    foo();
+
+    loop {}
+}
+
+#[exception]
+unsafe fn SysTick() {
+    foo();
+}
+
+unsafe fn foo() {}
diff --git a/cortex-m-rt/examples/warnings.rs b/cortex-m-rt/examples/warnings.rs
new file mode 100644
index 0000000..3372003
--- /dev/null
+++ b/cortex-m-rt/examples/warnings.rs
@@ -0,0 +1,50 @@
+//! Tests that a crate can still build with all warnings enabled.
+//!
+//! The code generated by the `cortex-m-rt` macros might need to manually
+//! `#[allow]` some of them (even though Rust does that by default for a few
+//! warnings too).
+
+#![no_std]
+#![no_main]
+#![deny(warnings, missing_docs, rust_2018_idioms)]
+
+extern crate cortex_m_rt;
+extern crate panic_halt;
+
+use cortex_m_rt::{entry, exception, interrupt, pre_init, ExceptionFrame};
+
+#[allow(non_camel_case_types)]
+enum interrupt {
+    INT,
+}
+
+extern "C" {
+    fn INT();
+}
+
+union Vector {
+    #[allow(dead_code)]
+    handler: unsafe extern "C" fn(),
+}
+
+#[link_section = ".vector_table.interrupts"]
+#[no_mangle]
+#[used]
+static __INTERRUPTS: [Vector; 1] = [Vector { handler: INT }];
+
+/// Dummy interrupt.
+#[interrupt]
+fn INT() {}
+
+#[exception]
+fn HardFault(_eh: &ExceptionFrame) -> ! {
+    loop {}
+}
+
+#[entry]
+fn main() -> ! {
+    loop {}
+}
+
+#[pre_init]
+unsafe fn pre_init() {}