diff --git a/src/main.rs b/src/main.rs
index a1c96cf..8132804 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -17,6 +17,13 @@ fn main() {
     // Skip the first arg which is the calling application name.
     let opt = Opt::from_iter(std::env::args().skip(1));
 
+    if opt.list_chips {
+        for vendor in vendor_map() {
+            println!("{}", vendor.0);
+        }
+        return;
+    }
+
     // Try and get the cargo project information.
     let project = cargo_project::Project::query(".").expect("Couldn't parse the Cargo.toml");
 
@@ -51,7 +58,7 @@ fn main() {
 
     // todo, keep as iter. difficult because we want to filter map remove two items at once.
     // Remove our args as cargo build does not understand them.
-    let flags = ["--pid", "--vid"].iter();
+    let flags = ["--pid", "--vid", "--chip"].iter();
     for flag in flags {
         if let Some(index) = args.iter().position(|x| x == flag) {
             args.remove(index);
@@ -76,6 +83,22 @@ fn main() {
     let d = if let (Some(v), Some(p)) = (opt.vid, opt.pid) {
         open_device_with_vid_pid(v, p)
             .expect("Are you sure device is plugged in and in bootloader mode?")
+    } else if let Some(c) = opt.chip {
+        println!("    {} for a connected {}.", "Searching".green().bold(), c);
+
+        let mut device: Option<rusb::DeviceHandle<GlobalContext>> = None;
+
+        let vendor = vendor_map();
+
+        if let Some(products) = vendor.get(&c) {
+            for (v, p) in products {
+                if let Some(d) = open_device_with_vid_pid(*v, *p) {
+                    device = Some(d);
+                    break;
+                }
+            }
+        }
+        device.expect("Are you sure device is plugged in and in bootloader mode?")
     } else {
         println!(
             "    {} for a connected device with known vid/pid pair.",
@@ -90,11 +113,9 @@ fn main() {
 
         let mut device: Option<rusb::DeviceHandle<GlobalContext>> = None;
 
-        let vendor = vendor_map();
-
         for d in devices {
-            if let Some(products) = vendor.get(&d.vendor_id()) {
-                if products.contains(&d.product_id()) {
+            for vendor in vendor_map() {
+                if vendor.1.contains(&(d.vendor_id(), d.product_id())) {
                     if let Some(d) = open_device_with_vid_pid(d.vendor_id(), d.product_id()) {
                         device = Some(d);
                         break;
@@ -107,7 +128,7 @@ fn main() {
 
     println!(
         "    {} {} {}",
-        "Trying ".green().bold(),
+        "Found ".green().bold(),
         d.read_manufacturer_string_ascii(&d.device().device_descriptor().unwrap())
             .unwrap(),
         d.read_product_string_ascii(&d.device().device_descriptor().unwrap())
@@ -182,4 +203,9 @@ struct Opt {
     pid: Option<u16>,
     #[structopt(name = "vid", long = "vid",  parse(try_from_str = parse_hex_16))]
     vid: Option<u16>,
+
+    #[structopt(name = "chip", long = "chip")]
+    chip: Option<String>,
+    #[structopt(name = "list-chips", long = "list-chips")]
+    list_chips: bool,
 }
diff --git a/src/utils.rs b/src/utils.rs
index a0d4be5..565359b 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -8,14 +8,15 @@ use std::{fs::File, io::Read};
 pub enum UtilError {
     Elf(goblin::error::Error),
     Dfu(dfu::error::Error),
-    File(std::io::Error)
+    File(std::io::Error),
 }
 
 /// Returns a contiguous bin with 0s between non-contiguous sections and starting address from an elf.
 pub fn elf_to_bin(path: PathBuf) -> Result<(Vec<u8>, u32), UtilError> {
     let mut file = File::open(path).map_err(|e| UtilError::File(e))?;
     let mut buffer = vec![];
-    file.read_to_end(&mut buffer).map_err(|e| UtilError::File(e))?;
+    file.read_to_end(&mut buffer)
+        .map_err(|e| UtilError::File(e))?;
 
     let binary = goblin::elf::Elf::parse(buffer.as_slice()).map_err(|e| UtilError::Elf(e))?;
 
@@ -58,9 +59,11 @@ pub fn flash_bin(
     address: u32,
     d: &rusb::Device<GlobalContext>,
 ) -> Result<(), UtilError> {
-    let mut dfu = dfu::Dfu::from_bus_device(d.bus_number(), d.address(), 0_u32, 0_u32).map_err(|e| UtilError::Dfu(e))?;
+    let mut dfu = dfu::Dfu::from_bus_device(d.bus_number(), d.address(), 0_u32, 0_u32)
+        .map_err(|e| UtilError::Dfu(e))?;
     if binary.len() < 2048 {
-        dfu.write_flash_from_slice(address, binary).map_err(|e| UtilError::Dfu(e))?;
+        dfu.write_flash_from_slice(address, binary)
+            .map_err(|e| UtilError::Dfu(e))?;
     } else {
         // hacky bug workaround
         std::fs::write("target/out.bin", binary).map_err(|e| UtilError::File(e))?;
@@ -71,15 +74,17 @@ pub fn flash_bin(
                 .map_err(|e| UtilError::File(e))?,
             address,
             None,
-        ).map_err(|e| UtilError::Dfu(e))?;
+        )
+        .map_err(|e| UtilError::Dfu(e))?;
         std::fs::remove_file("target/out.bin").map_err(|e| UtilError::File(e))?;
     }
 
     Ok(())
 }
 
-pub fn vendor_map() -> std::collections::HashMap<u16, Vec<u16>> {
+pub fn vendor_map() -> std::collections::HashMap<String, Vec<(u16, u16)>> {
     maplit::hashmap! {
-        0x0483 => vec![0xdf11],
+        "stm32f4".to_string() => vec![(0x0483, 0xdf11)],
+        "gd32vf103".to_string() =>  vec![(0x28e9, 0x0189)],
     }
 }