[doc, rust] Document the rust stack

Signed-off-by: Douglas Reis <[email protected]>

README.md

@@ -388,19 +388,28 @@ You may need to run the last command twice if you get the following error:
 
 
 
-## Building Software
+## Building Software 
+### C stack
 
 First the software must be built.
 This can be loaded into an FPGA to run on a synthesized Ibex processor, or passed
 to a verilator simulation model to be simulated on a PC.
 
 ```
-mkdir sw/build
-pushd sw/build
+mkdir sw/c/build
+pushd sw/c/build
 cmake ..
 make
 popd
 ```
+### Rust stack
+
+```sh
+pushd sw/rust
+cargo build --bin led
+popd
+```
+For more details, please refer to [Ibex Rust stack](sw/rust/README.md).
 
 Note the FPGA build relies on a fixed path to the initial binary (blank.vmem) so
 if you want to create your build directory elsewhere you need to adjust the path
@@ -418,14 +427,14 @@ fusesoc --cores-root=. run --target=sim --tool=verilator --setup --build lowrisc
 
 Having built the simulator and software, to simulate using Verilator we can use the following commands.
 `<sw_elf_file>` should be a path to an ELF file  (or alternatively a vmem file)
-built as described above. Use `./sw/build/demo/hello_world/demo` to run the `demo`
+built as described above. Use `./sw/c/build/demo/hello_world/demo` to run the `demo`
 binary.
 
 Run from the repository root run:
 ```
 # For example :
 ./build/lowrisc_ibex_demo_system_0/sim-verilator/Vibex_demo_system [-t] \
-  --meminit=ram,./sw/build/demo/hello_world/demo
+  --meminit=ram,./sw/c/build/demo/hello_world/demo
 
 # You need to substitute the <sw_elf_file> for a binary we have build above.
 ./build/lowrisc_ibex_demo_system_0/sim-verilator/Vibex_demo_system [-t] --meminit=ram,<sw_elf_file>
@@ -486,11 +495,11 @@ debugger.
 
 ```bash
 # Run demo
-./util/load_demo_system.sh run ./sw/build/demo/hello_world/demo
-./util/load_demo_system.sh run ./sw/build/demo/lcd_st7735/lcd_st7735
+./util/load_demo_system.sh run ./sw/c/build/demo/hello_world/demo
+./util/load_demo_system.sh run ./sw/c/build/demo/lcd_st7735/lcd_st7735
 
 # Load demo and start halted awaiting a debugger
-./util/load_demo_system.sh halt ./sw/build/demo/hello_world/demo
+./util/load_demo_system.sh halt ./sw/c/build/demo/hello_world/demo
 ```
 
 To view terminal output use screen:
@@ -517,7 +526,7 @@ Then run GDB against the running binary and connect to localhost:3333 as a
 remote target
 
 ```
-riscv32-unknown-elf-gdb ./sw/build/demo/hello_world/demo
+riscv32-unknown-elf-gdb ./sw/c/build/demo/hello_world/demo
 
 (gdb) target extended-remote localhost:3333
 ```

sw/rust/README.md

@@ -0,0 +1,15 @@
+# Ibex Rust stack
+This a embedded Rust software stack for whom is enthusiast about Rust, embedded systems, RISC-V and open source.
+
+## Installation
+Install Rust:<https://www.rust-lang.org/tools/install>.
+
+## Demos application
+- [Hello world](demo/hello_world/README.md)
+- [LED](demo/led/README.md)
+
+## Running on the ARTY A7 FPGA
+Before running, you need to build and load the bitstream to the board as described [here](../../README.md#building-fpga-bitstream).
+```
+cargo run --bin led
+```

sw/rust/demo/led/README.md

@@ -0,0 +1,14 @@
+# LED
+
+This is a interactive demo application that light the LEDs based on the the buttons pressed on the ARTY A7 board while outputs the logs via UART.
+
+## How to build and load
+1. Build and Load the bistream as described [here](../../../../README.md#building-fpga-bitstream).
+2. Connect to UART to see the console.
+    ```sh
+    screen /dev/ttyUSB1 115200
+    ```
+3. Build and load the application
+    ```
+    cargo run
+    ```

sw/rust/ibex-demo-system-pac/README.md

@@ -1,5 +1,5 @@
 # Ibex demo system PAC (Peripheral Access Crate)
-A Peripheral Access Crate (PAC) for the IBex Demo System from lowRISC. See the [svd2rust](https://docs.rs/svd2rust/0.29.0/svd2rust/) documentation for more information on how to use this crate.
+A Peripheral Access Crate (PAC) for the Ibex Demo System from lowRISC. See the [svd2rust](https://docs.rs/svd2rust/0.29.0/svd2rust/) documentation for more information on how to use this crate.
 
 The Ibex demo system pac is automatically generated when imported by cargo and it is based on the ibex.svd file. 
 ## How to generate manually (Optional)