Switch the current binary to use anyhow errors and add a proper argument number check

src/main.rs

@@ -19,6 +19,8 @@ use trve::{
     mem::{DeviceEntry, MemAccessFault, MemConfig, MemDeviceInterface, PageNum, Ram},
 };
 
+use anyhow::{Result, bail};
+
 use crate::basic_uart::BasicUart;
 
 fn read_file_to_buffer(path: &str, buffer: &mut [u8]) -> io::Result<usize> {
@@ -41,14 +43,15 @@ fn read_file_to_buffer(path: &str, buffer: &mut [u8]) -> io::Result<usize> {
     Ok(total_read)
 }
 
-fn main() -> Result<(), Box<dyn Error>> {
+fn main() -> Result<()> {
     let mut ram = Ram::try_new(16 * 1024 * 1024 / 4096)?;
     let buf = ram.buf_mut();
 
     let args: Vec<String> = env::args().collect();
 
     if args.len() != 2 {
-        eprintln!("USAGE: trve <ram_image>")
+        eprintln!("USAGE: trve <ram_image>");
+        bail!("Wrong number of arguments");
     }
 
     read_file_to_buffer(&args[1], buf)?;