Erhannis
commented
1 day ago While I'm not sure I've figured out all the weirdness that was going on, I did figure out some of it, and get a program running. Ironically, it's about a behavior I noticed like 3 months ago and asked about on Stack Overflow, and then forgot. https://stackoverflow.com/questions/78732542/rust-rp2040-entry-differences
I think at several points I removed the rp_pico crate, not needing it, and just using rp2040_hal. However, as it turns out, rp_pico declares the bootloader. If I didn't use rp_pico in some way, the bootloader didn't get written, and the code didn't run. So adding this to the main rs file fixed it:
#[link_section = ".boot2"]
#[no_mangle]
#[used]
pub static BOOT2_FIRMWARE: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;I'm not sure what was going on with the linking errors, but unless they happen again I probably won't investigate further.
Ubuntu 24.04.1 LTS RP2040 (Pico W)
For several hours I've been trying to get RTIC running (with defmt, and preferably debugging) on an RP2040. The results are a little baffling. I'm using probe-rs to flash the code.
I can compile and run https://github.com/rtic-rs/rtic/tree/master/examples/rp2040_local_i2c_init (if I add
runner = "probe-rs run --chip RP2040 --protocol swd"to config.toml), but I get the warning "WARN probe_rs::util::rtt: No RTT header info was present in the ELF file. Does your firmware run RTT?" I've tried adding defmt-rtt to Cargo.toml, added"-C", "link-arg=-Tdefmt.x",to config.toml, tried adding rtt features to various packages, but either nothing happens or I get linker errors. (I did just discover I can get debugging to work on it, so that's a plus.)I'm able to compile https://github.com/rtic-rs/defmt-app-template , once I fill in the various TODOs, but I get "ERROR probe_rs::cmd::run: Failed to attach to RTT, continuing...", and it doesn't seem like the code is actually running. Also, somehow when I copy the main code from the i2c_init example over the main code of the template (and tweak the imports to work), I get a linker error about defmt??? I can copy the old file (containing defmt calls) right back over it, and the linking error goes away, which baffles me. (I added some stuff to Cargo.toml to make the copied code compile, but haven't touched it since, and swapping the main code makes the linking error come and go, despite that both reference defmt.) Linker error:
Another weird thing I noticed earlier - I was at some point able to flash code to the device via e.g.
cargo runwhich didn't appear to run, but after I replugged the device it'd start running (e.g. led would start flashing). It's not doing it now, though.