Hello Eric, Please note that the rust-dev list is (for better or worse) abandonned.
You may ask questions on either IRC ( https://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust), the users forum (https://users.rust-lang.org/) or StackOverflow. You may also ask on Reddit (https://reddit.com/r/rust), however it's more used for announcements than questions in general. Note that all the community links I gave are accessible directly from http://www.rust-lang.org/ Good luck with your project! On Sat, May 30, 2015 at 8:49 PM, Eric Stutzenberger < dynamicstabil...@gmail.com> wrote: > I'm working on building out a Rust interface to the nRF51x series parts. > I have a bare metal system working quite well. The nRF51x has a bluetooth > stack (called Softdevice). This stack requires the use of supervisor calls > to request the stack to perform certain functions. My plan is to write a C > library wrapper around these service calls, compile with arm-none-wabi-gcc > and then link this to my Bare-metal rust system. A large chunk of the work > I have done thus far is based off of STM32 example work done by Jorge > Aparicio (https://github.com/japaric). > > Since I have the basics up and running, I am working on trying to get a C > static library built with arm-none-eabi-gcc and archived with > arm-none-eabi-ar to properly link in with my Rust code. > > I have the following (very basic) .c file: > uint32_t sum(uint32_t a, uint32_t b) > { > return a + b; > } > > I am compiling and linking with the following commands: > > arm-none-eabi-gcc -Wall -mcpu=cortex-m0 -mthumb -fPIC --specs=nosys.specs > -shared test.c -o test.o > > arm-none-eabi-ar -rs libtest.a test.o > > > In my rust file: > > [link(name="test", kind="static")] > > extern { > > pub fn sum(a: u32, b: u32) -> u32; > > } > > > I then invoke it as a test: > > pub fn main() { > > let test_sum = unsafe { sum(2, 3) }; > > } > > > I am using a Makefile to execute the rust compiler for some specific > arguments, such as my specific target: > > # rustc target > > TARGET = thumbv6m-none-eabi > > > # toolchain prefix > > TRIPLE = arm-none-eabi > > > APP_DIR = src/app > > OUT_DIR = target/$(TARGET)/release > > > DEPS_DIR = $(OUT_DIR)/deps > > > BINS = $(OUT_DIR)/%.hex > > HEXS = $(OUT_DIR)/%.hex > > ELFS = $(OUT_DIR)/%.elf > > OBJECTS = $(OUT_DIR)/intermediate/%.o > > SOURCES = $(APP_DIR)/%.rs > > > APPS = $(patsubst $(SOURCES),$(BINS),$(wildcard $(APP_DIR)/*.rs)) > > > RUSTC_FLAGS := -C lto -g $(RUSTC_FLAGS) > > > # don't delete my elf files! > > .SECONDARY: > > > all: rlibs $(APPS) > > > clean: > > cargo clean > > > # TODO $(APPS) should get recompiled when the `rlibs` change > > > $(OBJECTS): $(SOURCES) > > mkdir -p $(dir $@) > > rustc \ > > $(RUSTC_FLAGS) \ > > --crate-type staticlib \ > > --emit obj \ > > --target $(TARGET) \ > > -L $(DEPS_DIR) \ > > -L ../sd110_lib \ > > --verbose \ > > -o $@ \ > > -ltest \ > > $< > > > $(ELFS): $(OBJECTS) > > $(TRIPLE)-ld \ > > --gc-sections \ > > -T layout.ld \ > > -o $@ \ > > $< > > #size $@ > > > $(BINS): $(ELFS) > > $(TRIPLE)-objcopy \ > > -O ihex \ > > $< \ > > $@ > > > rlibs: > > cargo build --target $(TARGET) --verbose --release > > > The cargo.toml is as follows: > > [package] > > name = "bmd200eval" > > version = "0.1.0" > > authors = ["Eric Stutzenberger <eric.stutzenber...@rigado.com>"] > > > [dependencies.nrf51822] > > path = "../nrf51822.rs" > > > When I run make, I get the following output: > > . > > . > > . > > mkdir -p target/thumbv6m-none-eabi/release/intermediate/ > > rustc \ > > -C lto -g \ > > --crate-type staticlib \ > > --emit obj \ > > --target thumbv6m-none-eabi \ > > -L target/thumbv6m-none-eabi/release/deps \ > > -L ../sd110_lib \ > > --verbose \ > > -o target/thumbv6m-none-eabi/release/intermediate/blink.o \ > > -ltest \ > > src/app/blink.rs > > src/app/blink.rs:42:9: 42:17 warning: unused variable: `test_sum`, > #[warn(unused_variables)] on by default > > src/app/blink.rs:42 let test_sum = unsafe { sum(2, 3) }; > > ^~~~~~~~ > > arm-none-eabi-ld \ > > --gc-sections \ > > -T layout.ld \ > > -o target/thumbv6m-none-eabi/release/blink.elf \ > > target/thumbv6m-none-eabi/release/intermediate/blink.o > > target/thumbv6m-none-eabi/release/intermediate/blink.o: In function > `blink::main': > > git/rust-nrf/bmd200eval.rs/src/app/blink.rs:42: undefined reference to > `sum' > > > I have found numerous different references to linking Rust with C and > calling C from Rust but I haven't found a specific answer as to why this > will not link. As you can see in the Makefile, I have tried to > force rustc's hand in finding and linking against the library, but this > doesn't seem to make a difference. > > > Is there an issue with how I am building a library? > > Since rustc is generating a staticlib in this case, is there some > different method that needs to be used? > > > Note that I am avoiding the Clang compiler for the moment due to the > following: > > > https://devzone.nordicsemi.com/question/29628/using-clang-and-the-s110-issues-with-supervisor-calls-to-the-softdevice/ > > > Essentially, the gist of the above is that Clang is not quite producing > the correct supervisor assembly code for calling in to the bluetooth stack, > especially when optimizations are enabled. > > > Cheers, > > Eric > > _______________________________________________ > Rust-dev mailing list > Rust-dev@mozilla.org > https://mail.mozilla.org/listinfo/rust-dev > >
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