转换Pi Pico嵌入式Rust项目ELF文件时，elf2uf2-rs始终报“Unrecognized ABI”错误的解决咨询

问题描述 #

我一直在尝试为Pi Pico构建并运行一个简单的嵌入式Rust程序，但遇到了一个卡住的问题：编译过程完全正常，但在使用elf2uf2-rs将ELF文件转换为UF2格式时，始终收到错误提示：

Error: "Unrecognized ABI"

以下是我的项目配置和操作步骤：

项目文件内容 #

.cargo/config.toml

[build]
target = "thumbv6m-none-eabi"

[target.thumbv6m-none-eabi]
rustflags = [
    "-C", "link-arg=-Tlink.x",
    "-C", "link-arg=--nmagic",
    # This line is the magic bullet:
    "-C", "link-arg=-z", "-C", "link-arg=keep-section=.boot2",
]

src/main.rs

#![no_std]
#![no_main]

// FORCE the bootloader into the binary
#[link_section = ".boot2"]
#[used]
pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;

use panic_halt as _;

// Use the entry macro from the HAL, not cortex_m_rt
// This ensures the bootloader is linked correctly
use rp_pico::entry; 
use core::fmt::Write;
use embedded_hal::digital::OutputPin;

use rp_pico::hal::{
    clocks::{init_clocks_and_plls, Clock},
    fugit::RateExtU32,
    pac,
    sio::Sio,
    uart::{DataBits, StopBits, UartConfig, UartPeripheral},
    watchdog::Watchdog,
};

const XTAL_FREQ_HZ: u32 = 12_000_000;

#[entry]
fn main() -> ! {
    let mut pac = pac::Peripherals::take().unwrap();
    let core = pac::CorePeripherals::take().unwrap();

    let mut watchdog = Watchdog::new(pac.WATCHDOG);
    let sio = Sio::new(pac.SIO);

    let clocks = init_clocks_and_plls(
        XTAL_FREQ_HZ,
        pac.XOSC,
        pac.CLOCKS,
        pac.PLL_SYS,
        pac.PLL_USB,
        &mut pac.RESETS,
        &mut watchdog,
    )
    .ok()
    .unwrap();

    let pins = rp_pico::Pins::new(
        pac.IO_BANK0,
        pac.PADS_BANK0,
        sio.gpio_bank0,
        &mut pac.RESETS,
    );

    let uart_pins = (
        pins.gpio0.into_function(),
        pins.gpio1.into_function(),
    );

    let mut uart = UartPeripheral::new(pac.UART0, uart_pins, &mut pac.RESETS)
        .enable(
            UartConfig::new(
                115200.Hz(),
                DataBits::Eight,
                None,
                StopBits::One,
            ),
            clocks.peripheral_clock.freq(),
        )
        .unwrap();

    let mut buzzer = pins.gpio4.into_push_pull_output();

    let mut delay = cortex_m::delay::Delay::new(
        core.SYST,
        clocks.system_clock.freq().to_Hz(),
    );

    let _ = writeln!(uart, "cricket chirper starting");

    let mut seed: u32 = 12345;

    loop {
        seed = seed.wrapping_mul(1103515245).wrapping_add(12345);
        let seconds = (seed % 60) + 1;

        let _ = writeln!(uart, "waiting {} seconds", seconds);

        delay.delay_ms(seconds * 1000);

        let _ = writeln!(uart, "buzzing");

        for _ in 0..500 {
            let _ = buzzer.set_high();
            delay.delay_us(500);
            let _ = buzzer.set_low();
            delay.delay_us(500);
        }

        delay.delay_ms(500);
    }
}

build.rs

fn main() {
    println!("cargo:rerun-if-changed=memory.x");
}

Cargo.toml

[package]
name = "pico-buzzer"
version = "0.1.0"
edition = "2021"

[dependencies]
# Standard ARM crates
cortex-m = "0.7"
cortex-m-rt = "0.7"
panic-halt = "0.2"

# Hardware abstraction
embedded-hal = "1.0"
embedded-io = "0.6"

# The Pico HAL - 'rt' feature provides the linker script automatically
rp-pico = { version = "0.9", features = ["rt"] }
rp2040-boot2 = "0.3"

[profile.release]
panic = "abort"
opt-level = 3
lto = true
codegen-units = 1
debug = true

memory.x

MEMORY
{
    /* The 2nd stage bootloader is 256 bytes at the start of flash */
    FLASH : ORIGIN = 0x10000000, LENGTH = 2048K
    RAM   : ORIGIN = 0x20000000, LENGTH = 264K
}

执行的命令 #

cargo clean
cargo build --release

以上命令执行无异常，然后执行：

elf2uf2-rs target/thumbv6m-none-eabi/release/pico-buzzer

就会收到错误：

Error: "Unrecognized ABI"

解决方案建议 #

这个错误通常是elf2uf2-rs对ARM Thumb架构的ELF文件兼容性问题导致的，你可以尝试以下几种方法来解决：

1. 更新elf2uf2-rs到最新版本 #

旧版本的elf2uf2-rs可能存在对thumbv6m-none-eabi目标的识别缺陷，执行以下命令强制更新到最新版：

cargo install elf2uf2-rs --force

更新完成后再尝试转换ELF文件。

2. 使用cargo-uf2直接生成UF2文件 #

可以跳过手动调用elf2uf2-rs的步骤，直接通过cargo插件生成UF2：
首先安装cargo-uf2：

cargo install cargo-uf2

然后在项目目录执行：

cargo uf2 --release --target thumbv6m-none-eabi

该命令会直接编译并生成UF2文件，省去中间手动转换的步骤。

3. 替换为rp2040-elf2uf2工具 #

Raspberry Pi官方提供的rp2040-elf2uf2工具对Pi Pico的ELF文件兼容性更好，你可以通过以下方式获取并使用：

• 如果安装了Raspberry Pi Pico SDK，该工具已经包含在SDK的bin目录中
• 或者通过包管理器安装（比如在Ubuntu上可以用sudo apt install rp2040-elf-tools）
  然后执行转换命令：

rp2040-elf2uf2 target/thumbv6m-none-eabi/release/pico-buzzer pico-buzzer.uf2

4. 验证ELF文件的架构信息 #

可以用readelf工具检查生成的ELF文件是否符合预期：

readelf -h target/thumbv6m-none-eabi/release/pico-buzzer

查看输出中的Machine字段应该是ARM，ABI Version应该是兼容的版本（比如0）。如果这里显示的架构不对，可能需要检查你的Rust交叉编译工具链是否正确安装。

备注：内容来源于stack exchange，提问作者Jim