Merge pull request #41 from JordanRobo/patch-1

Update README.md

Author: romancardenas

README.md

@@ -31,6 +31,13 @@ One of:
 
 When using `dfu-util`, the RISC-V toolchain is not necessary. Only `rust-objcopy` from [cargo-binutils](https://github.com/rust-embedded/cargo-binutils) is needed.
 
+Option B - Install prebuilt toolchain (easier):
+
+For Ubuntu/Debian:
+```
+sudo apt-get install gcc-riscv64-unknown-elf
+```
+
 ### Building 
 
 If you have a GD32VF103C**B** chip on your board, edit `.cargo/config` and replace
@@ -63,6 +70,12 @@ Steps to flash an example via DFU:
 rust-objcopy -O binary target/riscv32imac-unknown-none-elf/release/examples/blinky firmware.bin
 ```
 
+If using prebuilt toolchain
+```sh
+riscv64-unknown-elf-objcopy -O binary target/riscv32imac-unknown-none-elf/release/blinky firmware.bin
+```
+
+
 2) Flash using `dfu-util`:
 
 Keep the BOOT0 button pressed while power-up or while pressing and releaseing the reset button. Then