Rust on the Stellaris Launchpad

A bare metal example program written in Rust (https://rust-lang.org) for the Stellaris Launchpad (LM4F120 dev board). May also work on the very closely related Tiva-C TM4C120 Launchpad.

The idea is that useful functionality will be moved out into separate crates.

Requirements

• rustc nightly
• xargo
• arm-none-eabi-gcc
• arm-none-eabi-ar
• arm-none-eabi-objcopy

Geting set up

bash cargo install xargo rustup install nightly git clone https://github.com/thejpster/launchpad-rs.git cd ./launchpad-rs rustup override set nightly rustup component add rust-src

Compile and upload

bash xargo build --example launchpad_blink arm-none-eabi-objcopy -O binary target/thumbv7em-none-eabihf/debug/examples/launchpad_blink target/thumbv7em-none-eabihf/debug/examples/launchpad_blink.bin sudo lm4flash target/thumbv7em-none-eabihf/debug/examples/launchpad_blink.bin

You can also debug

~/launchpad-rs $ sudo openocd -f /usr/share/openocd/scripts/board/ek-lm4f120xl.cfg ~/launchpad-rs $ arm-none-eabi-gdb ./target/thumbv7em-none-eabihf/debug/examples/launchpad_blink (gdb) target remote localhost:3333 (gdb) load Loading section .text, size 0x1e98 lma 0x0 Loading section .ARM.exidx, size 0x8 lma 0x1e98 Loading section .data, size 0xc lma 0x1ea0 Start address 0x0, load size 7852 Transfer rate: 7 KB/sec, 2617 bytes/write. (gdb) monitor reset halt (gdb) break main (gdb) continue

What works:

• UART works, using the on-board UART-to-USB bridge (115200 bps, 8N1)
• PLL runs at 66.7MHz
• SysTick works at 4MHz, providing a timer a currently use for the busy-waits
• GPIO works - you can control the on-board RGB LED
• Timer works - you can drive GPIOs (including the LED) with PWM
• Panic handler works - it quickly flashes the red LED if it panics or hits a hardfault