Merge #263

263: Import cortex-m-semihosting and panic-semihosting into this repo r=adamgreig a=jonas-schievink

Motivation:

* Allows writing QEMU tests for `cortex-m`'s functionality that use semihosting to control QEMU. Previously these crates would pull in another cortex-m version, which doesn't work. Now they have a `path` dependency on the root crate.
* Lets us share the outline-inline-assembly setup and `cargo-xtask` in general.
* Lets us share CI and bot setup between more crates.
* 2 fewer repos to triage and keep track of (I'll transfer their issues after this is merged).

I also want to import cortex-m-rt, but I'll do that in a later PR.

CI was updated to build-test all crates with all or most feature combinations, like it did before.

Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>

Author: bors[bot]

Cargo.toml

@@ -27,7 +27,7 @@ inline-asm = []
 linker-plugin-lto = []
 
 [workspace]
-members = ["xtask"]
+members = ["xtask", "cortex-m-semihosting", "panic-semihosting"]
 
 [package.metadata.docs.rs]
 targets = [

asm/inline.rs

@@ -175,6 +175,13 @@ pub unsafe fn __wfi() {
     asm!("wfi");
 }
 
+/// Semihosting syscall.
+#[inline(always)]
+pub unsafe fn __syscall(mut nr: u32, arg: u32) -> u32 {
+    asm!("bkpt #0xab", inout("r0") nr, in("r1") arg);
+    nr
+}
+
 // v7m *AND* v8m.main, but *NOT* v8m.base
 #[cfg(any(armv7m, armv8m_main))]
 pub use self::v7m::*;

asm/lib.rs

@@ -46,7 +46,7 @@ macro_rules! shims {
             pub unsafe extern "C" fn $name(
                 $($arg: $argty),*
             ) $(-> $ret)? {
-                crate::inline::$name($($arg)*)
+                crate::inline::$name($($arg),*)
             }
         )+
     };
@@ -72,9 +72,10 @@ shims! {
     fn __udf();
     fn __wfe();
     fn __wfi();
+    fn __syscall(nr: u32, arg: u32) -> u32;
 }
 
-// v7m *AND* v8m.main, but *NOT* v8m.base 
+// v7m *AND* v8m.main, but *NOT* v8m.base
 #[cfg(any(armv7m, armv8m_main))]
 shims! {
     fn __basepri_max(val: u8);