firmware: use libcompiler_builtins to build satman.

artiq/firmware/Cargo.lock

@@ -134,6 +134,7 @@ dependencies = [
  "alloc_artiq 0.0.0",
  "board 0.0.0",
  "build_artiq 0.0.0",
+ "compiler_builtins 0.1.0 (git+https://github.com/rust-lang-nursery/compiler-builtins)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "logger_artiq 0.0.0",
  "std_artiq 0.0.0",

artiq/firmware/satman/Cargo.toml

@@ -13,6 +13,7 @@ path = "lib.rs"
 build_artiq = { path = "../libbuild_artiq" }
 
 [dependencies]
+compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins" }
 alloc_artiq = { path = "../liballoc_artiq" }
 std_artiq = { path = "../libstd_artiq", features = ["alloc"] }
 logger_artiq = { path = "../liblogger_artiq" }

artiq/firmware/satman/Makefile

@@ -6,14 +6,18 @@ PYTHON ?= python3
 RUSTOUT := cargo/or1k-unknown-none/debug
 
 LDFLAGS += --gc-sections \
-	-L../libcompiler-rt \
 	-L../libbase
 
+RUSTFLAGS = \
+	-C target-feature=+mul,+div,+ffl1,+cmov,+addc \
+	-C opt-level=s \
+	-C panic=abort
+export RUSTFLAGS
+
 all: satman.bin satman.fbi
 
 .PHONY: $(RUSTOUT)/libsatman.a
 $(RUSTOUT)/libsatman.a:
-	RUSTFLAGS="-C target-feature=+mul,+div,+ffl1,+cmov,+addc -C opt-level=s -Cpanic=abort" \
 	CARGO_TARGET_DIR=$(realpath .)/cargo \
 		cargo build --target=or1k-unknown-none \
 			--manifest-path $(realpath $(SATMAN_DIRECTORY))/Cargo.toml
@@ -23,12 +27,9 @@ satman.elf: $(RUSTOUT)/libsatman.a
 		-T $(SATMAN_DIRECTORY)/satman.ld \
 		-o $@ \
 		$^ \
-		-lbase-nofloat -lcompiler-rt
+		-lbase-nofloat
 	@chmod -x $@
 
-%.o: $(SATMAN_DIRECTORY)/%.c
-	$(compile)
-
 %.bin: %.elf
 	$(OBJCOPY) -O binary $< $@
 	@chmod -x $@

artiq/firmware/satman/lib.rs

@@ -1,5 +1,7 @@
+#![feature(compiler_builtins_lib)]
 #![no_std]
 
+extern crate compiler_builtins;
 extern crate alloc_artiq;
 #[macro_use]
 extern crate std_artiq as std;