Merge pull request #87 from jsalzbergedu/master

Added more concrete documentation for compiling test binaries for redox

src/SUMMARY.md

@@ -94,7 +94,7 @@
             - [What is available and what is not]()
         - [Using schemes]()
         - [Using Orbital]()
-        - [Compiling your program]()
+        - [Compiling your program](./userspace/writing_application/compiling_program.md)
         - [A full example]()
     - [Porting a program]()
         - [Remove dependencies]()

src/userspace/writing_application/compiling_program.md

+# Compiling your program
+
+Consider this "hello world" program:
+
+
+```rust
+fn main() {
+    println!("Hello World!");
+}
+```
+
+To compile this program, you are going to need to edit some of your redox source files in such a way that your local redox repository will not be fit for updates via git or pull requests. It is reccomended that you do __not__ add the changes to the git history.
+
+Step one: Go to redox/programs, and run `cargo new helloworld --bin`. It should create a directory redox/programs/helloworld with a redox/programs/helloworld/Cargo.toml like this:
+
+```toml
+[package]
+name = "helloworld"
+version = "0.1.0"
+authors = ["Your Name <youremail@example.com>"]
+
+[dependencies]
+```
+You want to compile a binary, so edit it so that it looks like this:
+
+```toml
+[package]
+name = "helloworld"
+version = "0.1.0"
+authors = ["Your Name <youremail@example.com>"]
+
+[[bin]]
+name = "helloworld"
+path = "src/main.rs"
+
+[dependencies]
+```
+
+Step two: Note that binaries compiled from redox/programs have entries in the redox/Cargo.toml like this:
+
+```toml
+    "programs/userutils",
+```
+
+Add a line below it that points to the helloworld program:
+```toml
+    "programs/helloworld",
+```
+
+Step three: Open redox/mk/userspace/mod.mk. Notice how the target directories for the  binaries are listed after `userspace: \`, and that every line in that block has a `\` after it exept for the last one. Add a `\` to the last line of the block, and add
+
+```toml
+	filesystem/bin/helloworld
+```
+
+in a line inserted below.
+
+Step four: Run `make` then `make qemu.` Do not run `make all`: it seems that the binary is not compiled to the correct location if `make all` is run.
+
+Step five: Log in to redox, open the terminal, and run `helloworld`. It should print: "Hello World!"