Rust ESP32C3 Build Error: 'Cannot Find Linker Script link.x'

help
1

Hi everyone,

I’m working on an ESP32C3 embedded project, and I’m trying to integrate defmt for logging in my application using the reference defmt book, (Setup - defmt book). when I attempt to build the project, I encounter the following error:

error: linking with `rust-lld` failed: exit status: 1
  = note: rust-lld: error: cannot find linker script link.x

What I have tried:

config.toml:

</[target.riscv32imc-unknown-none-elf]
runner = "espflash flash --monitor"


[env]
ESP_LOGLEVEL="INFO"

[build]
rustflags = [

  "-C", "force-frame-pointers",
  "-C", "link-arg=-Tlink.x",
  "-C", "link-arg=--nmagic",
  "-C", "link-arg=-Tdefmt.x",
]

target = "riscv32imc-unknown-none-elf"

[unstable]
build-std = ["alloc", "core"]

I don’t currently have a link.x file in my project, which seems to be causing the issue. I am not entirely sure where to obtain the correct link.x file for the ESP32C3 or if I need to generate one manually. However I tried on adding link.x from (esp32c3-experiments/esp32c3-link.x at master · MabezDev/esp32c3-experiments · GitHub). But linking with rust-lld failed error still exists.

Is there anything else I should include in the .cargo/config.toml file to properly configure the linker for ESP32C3? Could you help me with any source where I can find or generate the correct link.x linker script. Please do help to troubleshoot the linker script issue and ensure the configuration.

Thank You!

2

the linker script is supposed to be provided by the runtime crate. for ARM cortex-m series microcontrollers, it's the cortex-m-rt crate; for RISC-V, it's the riscv-rt crate.

I have no experience with the esp32 series, but for RISC-V based products, I think it should be enough to include the riscv-rt crate as a dependency, and its build script should put the linker script at the correct location.

3

Yes, It's working. Thank you for your valid note.