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avr-rust / book.avr-rust.com

The AVR-Rust guidebook
https://book.avr-rust.com/
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Describe how to flash an Arduino Uno with avrdude #16

Closed mciantyre closed 3 years ago

mciantyre commented 3 years ago

The PR proposes flashing documentation. The documentation now describes how flash the blink example to an Arduino Uno.

We scatter avrdude installation instructions throughout the third-party tools section. Tested the two Linux installations in some VMs, and tested the macOS installation with brew.

The avrdude usage is similar to how the Arduino IDE flashes a sketch. We skip one step: the IDE first uses avr-objcopy to convert ELF -> Intel hex. But, avrdude supports ELF files (at least as of version 6.3, from around 2016). The documentation shows how to use the ELF file directly, rather than first converting to hex. It doesn't seem to matter if I first convert to hex, then flash, vs directly flashing the ELF output; avrdude reports that it's flashing the same number of bytes in either usage.

Tested flashing on macOS. Should work on Linux, but untested.

mciantyre commented 3 years ago

This continues using the .elf suffix in documentation, as noted in #13.

shepmaster commented 3 years ago

But, avrdude supports ELF files (at least as of version 6.3, from around 2016)

TIL! This will simplify some code.

shepmaster commented 3 years ago

The trailing :i indicates that the input is in Intel hex format. The trailing :e indicates an ELF input.

On second look at the avrdude manual, it looks like this field is optional.

Looks like (https://github.com/avr-rust/blink/issues/21) the avrdude shipped with WinAVR is old and doesn't support this.

mciantyre commented 3 years ago

Good to note WinAVR when the book provides Windows-specific documentation.

We could describe how to use objcopy to support old avrdudes:

If your avrdude tool does not support ELF files, first convert your Rust output to an Intel hex format:

avr-objcopy -O ihex target/avr-atmega328p/release/blink.elf target/avr-atmega328p/release/blink.hex

Then, replace -Uflash:w:target/avr-atmega328p/release/blink.elf:e with -Uflash:w:target/avr-atmega328p/release/blink.hex:i in the above avrdude command.

The book's Arch, Ubuntu, and macOS installation instructions should result in a system that has avr-objcopy, or some kind of objcopy. LLVM's objcopy, available from cargo binutils and aliased as rust-objcopy, also seemed to work during a quick blink test with my Uno.