Switch back to building as a binary.

cbiffle · Sep 17, 2016 · a8bd19ce13b7215c95db036b99b5a72d24e88bd3 · a8bd19c
1 parent 619b2e6
commit a8bd19ce13b7215c95db036b99b5a72d24e88bd3
Unified Split

Showing with 11 additions and 31 deletions.

+0 −1 .gitignore

+0 −3 Cargo.toml

+0 −26 Makefile

+4 −0 notes/20160916-entry.mkdn

+7 −1 src/{emb1.rs → main.rs}
diff --git a/.gitignore b/.gitignore
@@ -2,4 +2,3 @@ target
 .vagrant/
 .swp
 .*.swp
-  
-build/
diff --git a/Cargo.toml b/Cargo.toml
@@ -6,9 +6,6 @@ authors = ["cbiffle <code@cliffle.com>"]
 [dependencies]
 rust-libcore = "*"
-  
-[lib]
-  
-crate-type = ["staticlib"]
-  
-
 [profile.dev]
 panic = "abort"

diff --git a/Makefile b/Makefile
diff --git a/notes/20160916-entry.mkdn b/notes/20160916-entry.mkdn
@@ -56,6 +56,10 @@ complain.
 Disabling the `staticlib` crate type doesn't seem to matter.  The crate type
 being passed on the commandline is probably winning.
+  
+Okay, yes.  This project is actually building as a binary, and the apparent
+  
+crate type declaration is ignored.  The actual trick being used here is the fake
+  
+start item.
+  
+
 `#[no_mangle]` appears to affect external symbol visibility in staticlibs.  If I
 remove it from `ISR_VECTORS` the symbol is no longer visible in the object file

diff --git a/src/emb1.rs → src/main.rs b/src/emb1.rs → src/main.rs
@@ -1,5 +1,5 @@
 #![no_std]
-  
-#![feature(lang_items)]
+  
+#![feature(lang_items,start)]
 extern {
    /// This symbol is exported by the linker script, and defines the initial
@@ -73,3 +73,9 @@ extern fn panic_fmt() -> ! {loop {}}
 #[no_mangle]
 pub extern "C" fn abort() -> ! { loop {} }
+  
+/// This is included to mollify the compiler, but is not actually used and
+  
+/// doesn't wind up getting linked into the output.
+  
+#[start]
+  
+fn _start(_: isize, _: *const *const u8) -> isize {
+  
+    unsafe { (ISR_VECTORS.reset)() }
+  
+}