Use hpm_isp.bin by default if it exists when using flash command

README.md

@@ -33,10 +33,12 @@ sudo udevadm control --reload-rules
 # Write to flash (use default memory config)
 hpm_isp flash 0 write 0x400 flash.bin
 # Write to flash (use custom memory config)
+# Note: if hpm_isp.bin exists in the working directory, it will be used by default.
+# So you don't need to pass -c option explicitly.
 hpm_isp flash -c hpm_isp.bin 0 write 0x400 flash.bin
 # Read from flash
-hpm_isp read -c hpm_isp.bin 0 read 0x0 0x4000 flash.bin
-# Use config wizard to generate config file (save to hpm_isp.bin)
+hpm_isp read 0 read 0x0 0x4000 flash.bin
+# Use config wizard to generate config file (save as hpm_isp.bin)
 hpm_isp wizard
 ```
 

hpm_isp/src/main.rs

@@ -18,6 +18,8 @@ use hpm_isp::{
 };
 use hpm_rt::XpiNorConfigurationOption;
 
+const DEFAULT_CONFIG_FILE: &'static str = "hpm_isp.bin";
+
 #[derive(Parser)]
 #[clap(version, about)]
 struct Cli {
@@ -41,7 +43,7 @@ enum Commands {
  /// Command of wizard to generate memory config file
  Wizard {
  /// Path of memory config file
- #[clap(short, long, default_value = "hpm_isp.bin")]
+ #[clap(short, long, default_value = DEFAULT_CONFIG_FILE)]
  path: PathBuf,
  },
 }
@@ -97,19 +99,25 @@ fn main() -> Result<(), Box<dyn Error>> {
  {
  let device = hid::HpmDevice::open().or_else(|_| Err("can't open HPMicro usb device"))?;
  let mut memory_config_bin = Vec::new();
-
- if let Some(path) = config {
- let mut config_file = fs::File::open(path)?;
-
- memory_config_bin.resize(12, 0);
- config_file.read_exact(memory_config_bin.as_mut_slice())?;
- if memory_config_bin[3] != 0xFC || memory_config_bin[2] != 0xF9 {
- return Err("Invalid memory config file".into());
+ let is_default = config.is_none();
+ let config_path = config.unwrap_or(DEFAULT_CONFIG_FILE.into());
+
+ match fs::File::open(config_path) {
+ Ok(mut config_file) => {
+ memory_config_bin.resize(12, 0);
+ config_file.read_exact(memory_config_bin.as_mut_slice())?;
+ if memory_config_bin[3] != 0xFC || memory_config_bin[2] != 0xF9 {
+ return Err("Invalid memory config file".into());
+ }
+ }
+ // Use default config file and it isn't exists
+ Err(_) if is_default => {
+ let xpi_config = XpiNorConfigurationOption::new();
+ xpi_config.write(&mut memory_config_bin)?;
+ }
+ Err(err) => {
+ Err(err)?;
  }
- } else {
- let xpi_config = XpiNorConfigurationOption::new();
-
- xpi_config.write(&mut memory_config_bin)?;
  }
 
  // Config memory