Add ROM version of read-flash command (#812)

* Add `ROM` version of `read-flash` command

* changelog entry

* dumb

Author: playfulFence

.github/workflows/hil.yml

@@ -134,4 +134,4 @@ jobs:
         run: timeout 20 bash espflash/tests/scripts/write-bin.sh
 
       - name: read-flash test
-        run: timeout 20 bash espflash/tests/scripts/read-flash.sh
+        run: timeout 30 bash espflash/tests/scripts/read-flash.sh

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [cargo-espflash]: Add `write-bin` subcommand (#789)
 - Add `--monitor` option to `write-bin`. (#783)
 - Add `watchdog-reset` strategy to `--after` subcommand (#779)
+- Add `ROM` version of `read-flash` command (#812)
 
 ### Changed
 

espflash/src/cli/mod.rs

@@ -850,19 +850,26 @@ fn erase_partition(flasher: &mut Flasher, part: &Partition) -> Result<()> {
 
 /// Read flash content and write it to a file
 pub fn read_flash(args: ReadFlashArgs, config: &Config) -> Result<()> {
-    if args.connect_args.no_stub {
-        return Err(Error::StubRequired.into());
-    }
-
     let mut flasher = connect(&args.connect_args, config, false, false)?;
     print_board_info(&mut flasher)?;
-    flasher.read_flash(
-        args.address,
-        args.size,
-        args.block_size,
-        args.max_in_flight,
-        args.file,
-    )?;
+
+    if args.connect_args.no_stub {
+        flasher.read_flash_rom(
+            args.address,
+            args.size,
+            args.block_size,
+            args.max_in_flight,
+            args.file,
+        )?;
+    } else {
+        flasher.read_flash(
+            args.address,
+            args.size,
+            args.block_size,
+            args.max_in_flight,
+            args.file,
+        )?;
+    }
 
     Ok(())
 }

espflash/src/connection/command.rs

@@ -56,6 +56,7 @@ pub enum CommandType {
     EraseFlash = 0xD0,
     EraseRegion = 0xD1,
     ReadFlash = 0xD2,
+    ReadFlashSlow = 0x0E, // ROM only, much slower than the stub read_flash
     RunUserCode = 0xD3,
     // Flash encryption debug mode supported command
     FlashEncryptedData = 0xD4,
@@ -189,6 +190,12 @@ pub enum Command<'a> {
         block_size: u32,
         max_in_flight: u32,
     },
+    ReadFlashSlow {
+        offset: u32,
+        size: u32,
+        block_size: u32,
+        max_in_flight: u32,
+    },
     RunUserCode,
     FlashDetect,
     GetSecurityInfo,
@@ -218,6 +225,7 @@ impl Command<'_> {
             Command::EraseFlash { .. } => CommandType::EraseFlash,
             Command::EraseRegion { .. } => CommandType::EraseRegion,
             Command::ReadFlash { .. } => CommandType::ReadFlash,
+            Command::ReadFlashSlow { .. } => CommandType::ReadFlashSlow,
             Command::RunUserCode { .. } => CommandType::RunUserCode,
             Command::FlashDetect => CommandType::FlashDetect,
             Command::GetSecurityInfo => CommandType::GetSecurityInfo,
@@ -417,6 +425,22 @@ impl Command<'_> {
                 writer.write_all(&block_size.to_le_bytes())?;
                 writer.write_all(&(max_in_flight.to_le_bytes()))?;
             }
+            Command::ReadFlashSlow {
+                offset,
+                size,
+                block_size,
+                max_in_flight,
+            } => {
+                // length
+                writer.write_all(&(16u16.to_le_bytes()))?;
+                // checksum
+                writer.write_all(&(0u32.to_le_bytes()))?;
+                // data
+                writer.write_all(&offset.to_le_bytes())?;
+                writer.write_all(&size.to_le_bytes())?;
+                writer.write_all(&block_size.to_le_bytes())?;
+                writer.write_all(&(max_in_flight.to_le_bytes()))?;
+            }
             Command::RunUserCode => {
                 write_basic(writer, &[], 0)?;
             }

espflash/src/flasher/mod.rs

@@ -1214,6 +1214,63 @@ impl Flasher {
         Ok(())
     }
 
+    pub fn read_flash_rom(
+        &mut self,
+        offset: u32,
+        size: u32,
+        block_size: u32,
+        max_in_flight: u32,
+        file_path: PathBuf,
+    ) -> Result<(), Error> {
+        // ROM read limit per command
+        const BLOCK_LEN: usize = 64;
+
+        let mut data: Vec<u8> = Vec::new();
+
+        let mut file = fs::OpenOptions::new()
+            .write(true)
+            .truncate(true)
+            .create(true)
+            .open(&file_path)?;
+
+        let mut correct_offset = offset;
+
+        while data.len() < size as usize {
+            let block_len = std::cmp::min(BLOCK_LEN, size as usize - data.len());
+
+            correct_offset += data.len() as u32;
+
+            let response = self.connection.with_timeout(
+                CommandType::ReadFlashSlow.timeout(),
+                |connection| {
+                    connection.command(Command::ReadFlashSlow {
+                        offset: correct_offset,
+                        size: block_len as u32,
+                        block_size,
+                        max_in_flight,
+                    })
+                },
+            )?;
+
+            let payload: Vec<u8> = response.try_into()?;
+
+            assert!(payload.len() >= block_len);
+
+            // command always returns 64 byte buffer,
+            // regardless of how many bytes were actually read from flash
+            data.append(&mut payload[..block_len].to_vec());
+        }
+
+        file.write_all(&data)?;
+
+        info!(
+            "Flash content successfully read and written to '{}'!",
+            file_path.display()
+        );
+
+        Ok(())
+    }
+
     pub fn read_flash(
         &mut self,
         offset: u32,

espflash/tests/scripts/read-flash.sh

@@ -33,6 +33,21 @@ for len in "${lengths[@]}"; do
         echo "Verification failed: content does not match expected for length"
         exit 1
     fi
+
+    echo "Testing ROM read-flash with length: $len"
+    result=$(espflash read-flash --no-stub 0 "$len" flash_content.bin 2>&1)
+    echo "$result"
+
+    if ! cmp -s <(echo -ne "$EXPECTED") flash_content.bin; then
+        echo "Verification failed: content does not match expected for length"
+        exit 1
+    fi
+
+    if [[ ! $result =~ "Flash content successfully read and written to" ]]; then
+        echo "Failed to read $len bytes from flash"
+        exit 1
+    fi
+
 done
 
 echo "All read-flash tests passed!"