some cleanup

echo.S

@@ -1,18 +0,0 @@
-.section .text
-.globl _start
-
-.equ UART_DATA, 0
-.equ UART_STATUS, 1
-.equ UART_RX_READY, 0b10
-.equ UART_TX_READY, 0b01
-
-_start:
-    li a0, 0x10000
-
-loop:
-    lbu t0, UART_STATUS(a0)
-    andi t0, t0, UART_RX_READY
-    beqz t0, loop
-    lbu t0, UART_DATA(a0)
-    sb t0, UART_DATA(a0)
-    j loop

src/main.rs

@@ -4,7 +4,7 @@
 // This file is part of TRVE (https://gitea.taitep.se/taitep/trve)
 // See LICENSE file in the project root for full license text.
 
-use std::{io, os::fd::AsFd, path::PathBuf, sync::Arc, time::Duration};
+use std::{io, path::PathBuf, sync::Arc, time::Duration};
 
 use clap::Parser;
 
@@ -42,16 +42,13 @@ fn main() -> Result<()> {
     let mut mmio_root = MmioRoot::default();
     mmio_root.insert(0, Arc::new(DbgOut));
 
-    if let Err(e) = fcntl(io::stdin().as_fd(), FcntlArg::F_SETFL(OFlag::O_NONBLOCK)) {
+    if let Err(e) = fcntl(io::stdin(), FcntlArg::F_SETFL(OFlag::O_NONBLOCK)) {
         eprintln!("Could not make stdout nonblocking, skipping. Error: {e}");
     }
 
     let uart = devices::serial::SifiveUart::new_arc();
-    uart.clone().spawn_io_thread(
-        std::io::stdin(),
-        std::io::stdout(),
-        Duration::from_millis(10),
-    );
+    uart.clone()
+        .spawn_io_thread(io::stdin(), io::stdout(), Duration::from_millis(10));
     mmio_root.insert(0x10000, uart);
 
     let mem_cfg = MemConfig {