Initial support for increased flashing speeds for the ESP32

cargo-espflash/src/main.rs

@@ -35,6 +35,8 @@ fn main() -> Result<(), MainError> {
 
     let port = args.serial.or(config.connection.serial).unwrap();
 
+    let speed = args.speed.map(|v| BaudRate::from_speed(v as usize));
+
     let chip = args
         .chip
         .as_ref()
@@ -63,11 +65,10 @@ fn main() -> Result<(), MainError> {
     let mut serial = serial::open(&port)?;
     serial.reconfigure(&|settings| {
         settings.set_baud_rate(BaudRate::Baud115200)?;
-
         Ok(())
     })?;
 
-    let mut flasher = Flasher::connect(serial)?;
+    let mut flasher = Flasher::connect(serial, speed)?;
     if args.board_info {
         return board_info(&flasher);
     }
@@ -94,6 +95,7 @@ struct AppArgs {
     example: Option<String>,
     chip: Option<String>,
     build_tool: Option<String>,
+    speed: Option<u32>,
     serial: Option<String>,
 }
 
@@ -105,6 +107,7 @@ fn usage() -> Result<(), MainError> {
       [--example EXAMPLE] \
       [--tool {{cargo,xargo,xbuild}}] \
       [--chip {{esp32,esp8266}}] \
+      [--speed BAUD] \
       <serial>";
 
     println!("{}", usage);
@@ -136,6 +139,7 @@ fn parse_args() -> Result<AppArgs, MainError> {
         release: args.contains("--release"),
         example: args.opt_value_from_str("--example")?,
         chip: args.opt_value_from_str("--chip")?,
+        speed: args.opt_value_from_str("--speed")?,
         build_tool: args.opt_value_from_str("--tool")?,
         serial: args.free_from_str()?,
     };
@@ -217,7 +221,7 @@ fn build(release: bool, example: &Option<String>, tool: &str, target: &str) -> E
 
 fn chip_detect(port: &str) -> Option<&'static str> {
     let serial = serial::open(port).ok()?;
-    let flasher = Flasher::connect(serial).ok()?;
+    let flasher = Flasher::connect(serial, None).ok()?;
 
     let chip = match flasher.chip() {
         Chip::Esp8266 => "esp8266",

espflash/src/connection.rs

@@ -1,12 +1,12 @@
-use std::io::Write;
+use std::io::{Write};
 use std::thread::sleep;
 use std::time::Duration;
 
 use crate::encoder::SlipEncoder;
 use crate::error::{Error, RomError};
 use binread::io::Cursor;
 use binread::{BinRead, BinReaderExt};
-use serial::SerialPort;
+use serial::{SerialPort, BaudRate, SerialPortSettings};
 use slip_codec::Decoder;
 
 pub struct Connection {
@@ -66,6 +66,13 @@ impl Connection {
         Ok(())
     }
 
+    pub fn set_baud(&mut self, speed: BaudRate) -> Result<(), Error> {
+        self.serial.reconfigure(&|setup: &mut dyn SerialPortSettings| {
+            setup.set_baud_rate(speed)
+        })?;
+        Ok(())
+    }
+
     pub fn with_timeout<T, F: FnMut(&mut Connection) -> Result<T, Error>>(
         &mut self,
         timeout: Duration,

espflash/src/flasher.rs

@@ -8,7 +8,7 @@ use crate::error::RomError;
 use crate::Error;
 use bytemuck::__core::time::Duration;
 use bytemuck::{bytes_of, Pod, Zeroable};
-use serial::SerialPort;
+use serial::{SerialPort,BaudRate};
 use std::thread::sleep;
 
 type Encoder<'a> = SlipEncoder<'a, Box<dyn SerialPort>>;
@@ -38,6 +38,7 @@ enum Command {
     ReadReg = 0x0a,
     SpiSetParams = 0x0B,
     SpiAttach = 0x0D,
+    ChangeBaud = 0x0F,
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
@@ -109,9 +110,9 @@ pub struct Flasher {
 }
 
 impl Flasher {
-    pub fn connect(serial: impl SerialPort + 'static) -> Result<Self, Error> {
+    pub fn connect(serial: impl SerialPort + 'static, speed: Option<BaudRate>) -> Result<Self, Error> {
         let mut flasher = Flasher {
-            connection: Connection::new(serial),
+            connection: Connection::new(serial), // default baud is always 115200
             chip: Chip::Esp8266, // dummy, set properly later
             flash_size: FlashSize::Flash4MB,
         };
@@ -121,6 +122,16 @@ impl Flasher {
         flasher.enable_flash()?;
         flasher.flash_detect()?;
 
+        if let Some(b) = speed {
+            match flasher.chip {
+                Chip::Esp8266 => (), /* Not available */
+                Chip::Esp32 => if b.speed() > BaudRate::Baud115200.speed() {
+                    println!("WARN setting baud rate higher than 115200 can cause issues.");
+                    flasher.change_baud(b)?;
+                }
+            }
+        }
+
         Ok(flasher)
     }
 
@@ -369,7 +380,6 @@ impl Flasher {
     ///
     /// Note that this will not touch the flash on the device
     pub fn load_elf_to_ram(&mut self, elf_data: &[u8]) -> Result<(), Error> {
-        self.start_connection()?;
         let image = FirmwareImage::from_data(elf_data).map_err(|_| Error::InvalidElf)?;
 
         if image.rom_segments(self.chip).next().is_some() {
@@ -401,7 +411,6 @@ impl Flasher {
 
     /// Load an elf image to flash and execute it
     pub fn load_elf_to_flash(&mut self, elf_data: &[u8]) -> Result<(), Error> {
-        self.start_connection()?;
         self.enable_flash()?;
         let mut image = FirmwareImage::from_data(elf_data).map_err(|_| Error::InvalidElf)?;
         image.flash_size = self.flash_size();
@@ -436,6 +445,12 @@ impl Flasher {
 
         Ok(())
     }
+
+    pub fn change_baud(&mut self, speed: BaudRate) -> Result<(), Error> {
+        self.connection.command(Command::ChangeBaud as u8, &(speed.speed()).to_le_bytes()[..], 0)?;
+        self.connection.set_baud(speed)?;
+        Ok(())
+    }
 }
 
 fn get_erase_size(offset: usize, size: usize) -> usize {

espflash/src/main.rs

@@ -41,7 +41,7 @@ fn main() -> Result<(), MainError> {
         Ok(())
     })?;
 
-    let mut flasher = Flasher::connect(serial)?;
+    let mut flasher = Flasher::connect(serial, None)?;
 
     if board_info {
         println!("Chip type: {:?}", flasher.chip());