Add USB serial stdout for RP2040

Builds on the capabilities of the BSP. Unlike the other hardare-specific
packages, I'm using alloc for conveying stdout messages. Check out the
imxrt stdout package for a different approach.

1 files changed, 2 insertions, 1 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 317c5b3..3df1b7b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -775,8 +775,9 @@ dependencies = [
  "embedded-hal 1.0.0",
  "rp-pico",
  "rust-threadx-cortex-m",
- "rust-threadx-stdio-semihosting",
  "rust-threadx-sync-single-core",
+ "usb-device",
+ "usbd-serial",
 ]
 
 [[package]]