Fix system attribute addressing

tockloader-lib/src/attributes/decode.rs

@@ -41,7 +41,11 @@ pub(crate) fn decode_attribute(step: &[u8]) -> Option<DecodedAttribute> {
 
     let mut key = String::new();
     for n in decoder_key {
-        key.push(n.expect("Error getting key for attributes."));
+        // TODO: This should not expect, we should return none in case the chip doesn't have a bootloader
+        match n {
+            Ok(c) => key.push(c),
+            Err(_) => return None,
+        }
     }
 
     key = key.trim_end_matches('\0').to_string();
@@ -56,27 +60,13 @@ pub(crate) fn decode_attribute(step: &[u8]) -> Option<DecodedAttribute> {
     let mut value = String::new();
 
     for n in decoder_value {
-        value.push(n.expect("Error getting key for attributes."));
+        // TODO: This should not expect, we should return none in case the chip doesn't have a bootloader
+        match n {
+            Ok(c) => value.push(c),
+            Err(_) => return None,
+        }
     }
 
     value = value.trim_end_matches('\0').to_string();
     Some(DecodedAttribute::new(key, value))
 }
-
-// TODO(eva-cosma) replace this function with std::str::from_utf8(...). It
-// does the same thing.
-
-/// Transform a byte-slice into a String.
-///
-/// # Panics
-///
-/// This code panics if the given bytes are not utf-8 representable
-pub(crate) fn bytes_to_string(raw: &[u8]) -> String {
-    let decoder = utf8_decode::Decoder::new(raw.iter().cloned());
-
-    let mut string = String::new();
-    for n in decoder {
-        string.push(n.expect("Error getting key for attributes."));
-    }
-    string
-}

tockloader-lib/src/attributes/system_attributes.rs

@@ -7,7 +7,7 @@ use byteorder::{ByteOrder, LittleEndian};
 use crate::errors::{AttributeParseError, TockError, TockloaderError};
 use crate::IO;
 
-use super::decode::{bytes_to_string, decode_attribute};
+use super::decode::decode_attribute;
 
 /// This structure contains all relevant information about board that is stored
 /// in the bootloader ROM.
@@ -48,12 +48,28 @@ impl SystemAttributes {
         }
     }
 
-    /// Read system attributes using a generalized connection. A bootloader must be
-    /// present on this board for this function to work properly.
-    ///
+    /// Check if the bootloader is present on the version of Tock
+    pub(crate) async fn bootloader_is_present(
+        conn: &mut dyn IO,
+        flash_address: u64,
+    ) -> Result<bool, TockloaderError> {
+        // If a bootloader is present, the start of 0x400 will read
+        // "TOCKBOOTLOADER", which is exactly 14 bytes long, so we'll read
+        // 14 bytes starting from 0x400.
+        let flag = conn.read(flash_address + 0x400, 14).await?;
+        if flag == "TOCKBOOTLOADER".as_bytes() {
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+    /// Read system and kernel attributes.
+    /// System attributes are read only if the board has
+    /// a bootloader present.
     /// # Parameters
-    /// - `conn` : Either a SerialConnection or a ProbeRSConnection
-    ///
+    /// - `conn` : Either a SerialConnection or a ProbeRSConnection.
+    /// - `flash_address` : The start of flash memory.
+    /// - `start_address` : The start of User Space Applications in flash memory.
     /// # Returns
     /// - Ok(result): if attributes were read successfully
     /// - Err(TockloaderError::MisconfiguredBoard): if no start address is found or valid
@@ -62,74 +78,91 @@ impl SystemAttributes {
     /// - Err(TockloaderError::SerialReadError): if reading fails on Serial
     pub(crate) async fn read_system_attributes(
         conn: &mut dyn IO,
+        flash_address: u64,
+        start_address: u64,
     ) -> Result<SystemAttributes, TockloaderError> {
         let mut result = SystemAttributes::new();
         // System attributes start at 0x600 and up to 0x9FF. See:
         // https://book.tockos.org/doc/memory_layout#flash-1
-        let address = 0x600;
+        let address = flash_address + 0x600;
 
         let buf = conn.read(address, 64 * 16).await?;
 
         let mut data = buf.chunks(64);
 
-        for current_slot in 0..data.len() {
-            let slot_data = match data.next() {
-                Some(data) => data,
-                None => break,
-            };
-
-            // If the attribute chunk was successfully decoded, assign its value
-            // to the corresponding field in `result` based on the index:
-            // - 0 = board name,
-            // - 1 = architecture,
-            // - 2 = application start address (parsed from hex string),
-            // - 3 = boot hash, _ = invalid or missing data is skipped.
-            // NOTE: this can also be done by looping directly through the key attributes.
-            if let Some(decoded_attributes) = decode_attribute(slot_data) {
-                match current_slot {
-                    0 => {
-                        result.board = Some(decoded_attributes.value.to_string());
-                    }
-                    1 => {
-                        result.arch = Some(decoded_attributes.value.to_string());
-                    }
-                    2 => {
-                        // Parse hex string like "0x40000" into actual u64 value
-                        result.appaddr = Some(
-                            u64::from_str_radix(
-                                decoded_attributes
-                                    .value
-                                    .to_string()
-                                    .trim_start_matches("0x"),
-                                16,
-                            )
-                            .map_err(|e| {
-                                TockError::AttributeParsing(AttributeParseError::InvalidNumber(e))
-                            })?,
-                        );
-                    }
-                    3 => {
-                        result.boothash = Some(decoded_attributes.value.to_string());
+        let has_bootloader = Self::bootloader_is_present(conn, flash_address)
+            .await
+            .unwrap_or(false);
+
+        if !has_bootloader {
+            // TODO: Chain: CLI arguments -> hardcoded start_address -> calculate from kernel app start address
+            result.appaddr = Some(start_address);
+        } else {
+            for current_slot in 0..data.len() {
+                let slot_data = match data.next() {
+                    Some(data) => data,
+                    None => break,
+                };
+
+                // If the attribute chunk was successfully decoded, assign its value
+                // to the corresponding field in `result` based on the index:
+                // - 0 = board name,
+                // - 1 = architecture,
+                // - 2 = application start address (parsed from hex string),
+                // - 3 = boot hash, _ = invalid or missing data is skipped.
+                // NOTE: this can also be done by looping directly through the key attributes.
+                if let Some(decoded_attributes) = decode_attribute(slot_data) {
+                    match current_slot {
+                        0 => {
+                            result.board = Some(decoded_attributes.value.to_string());
+                        }
+                        1 => {
+                            result.arch = Some(decoded_attributes.value.to_string());
+                        }
+                        2 => {
+                            // Parse hex string like "0x40000" into actual u64 value
+                            result.appaddr = Some(
+                                u64::from_str_radix(
+                                    decoded_attributes
+                                        .value
+                                        .to_string()
+                                        .trim_start_matches("0x"),
+                                    16,
+                                )
+                                .map_err(|e| {
+                                    TockError::AttributeParsing(AttributeParseError::InvalidNumber(
+                                        e,
+                                    ))
+                                })?,
+                            );
+                        }
+                        3 => {
+                            result.boothash = Some(decoded_attributes.value.to_string());
+                        }
+                        _ => {}
                     }
-                    _ => {}
+                } else {
+                    continue;
                 }
-            } else {
-                continue;
             }
-        }
-
-        // TODO(eva-cosma): separate kernel attributes from kernel flags.
 
-        let address = 0x40E;
+            // At this address lives the version of the bootloader we are using.
+            // Trying to read this when no bootloader is present will result in a panic.
+            // So we first verify if we have a bootloader, if not we just skip this and
+            // return None for the bootloader version.
+            let address = flash_address + 0x40E;
 
-        let buf = conn.read(address, 8).await?;
+            let buf = conn.read(address, 8).await?;
 
-        let string = String::from_utf8(buf.to_vec())
-            .map_err(|e| TockError::AttributeParsing(AttributeParseError::InvalidString(e)))?;
+            let string = String::from_utf8(buf.to_vec())
+                .map_err(|e| TockError::AttributeParsing(AttributeParseError::InvalidString(e)))?;
 
-        let string = string.trim_matches(char::from(0));
+            let string = string.trim_matches(char::from(0));
 
-        result.bootloader_version = Some(string.to_owned());
+            result.bootloader_version = Some(string.to_owned());
+        }
+
+        // TODO(eva-cosma): separate kernel attributes from kernel flags.
 
         // The 100 bytes prior to the application start address are reserved for the kernel attributes and flags
         let kernel_attr_addr = result
@@ -138,7 +171,9 @@ impl SystemAttributes {
             - 100;
         let kernel_attr_binary = conn.read(kernel_attr_addr, 100).await?;
 
-        let sentinel = bytes_to_string(&kernel_attr_binary[96..100]);
+        let sentinel = std::str::from_utf8(&kernel_attr_binary[96..100])
+            .unwrap_or("unknown")
+            .to_string();
         let kernel_version = LittleEndian::read_uint(&kernel_attr_binary[95..96], 1);
 
         let app_memory_len = LittleEndian::read_u32(&kernel_attr_binary[84..92]);

tockloader-lib/src/board_settings.rs

@@ -1,6 +1,7 @@
 #[derive(Clone)]
 pub struct BoardSettings {
     pub arch: Option<String>,
+    pub flash_address: u64,
     pub start_address: u64,
     pub page_size: u64,
     pub ram_start_address: u64,
@@ -12,6 +13,7 @@ impl Default for BoardSettings {
     fn default() -> Self {
         Self {
             arch: None,
+            flash_address: 0x00000, // this would be actually like -0x10000
             start_address: 0x30000,
             page_size: 512,
             ram_start_address: 0x20000000,

tockloader-lib/src/bootloader_serial.rs

@@ -156,7 +156,6 @@ async fn write_bytes(
     .map_err(|_| TockError::BootloaderTimeout)?
 }
 
-#[allow(dead_code)]
 pub async fn ping_bootloader_and_wait_for_response(
     port: &mut SerialStream,
 ) -> Result<(), TockloaderError> {

tockloader-lib/src/command_impl/info.rs

@@ -8,8 +8,8 @@ use crate::{CommandInfo, IOCommands};
 #[async_trait]
 impl CommandInfo for TockloaderConnection {
     async fn info(&mut self) -> Result<GeneralAttributes, TockloaderError> {
-        let installed_apps = self.read_installed_apps().await.unwrap();
-        let system_atributes = self.read_system_attributes().await.unwrap();
+        let installed_apps = self.read_installed_apps().await?;
+        let system_atributes = self.read_system_attributes().await?;
         Ok(GeneralAttributes::new(system_atributes, installed_apps))
     }
 }

tockloader-lib/src/command_impl/probers/io.rs

@@ -53,7 +53,10 @@ impl IOCommands for ProbeRSConnection {
         if !self.is_open() {
             return Err(InternalError::ConnectionNotOpen.into());
         }
-        let system_attributes = SystemAttributes::read_system_attributes(self).await?;
+        let flash_address = self.get_settings().flash_address;
+        let start_address = self.get_settings().start_address;
+        let system_attributes =
+            SystemAttributes::read_system_attributes(self, flash_address, start_address).await?;
         Ok(system_attributes)
     }
 }

tockloader-lib/src/command_impl/reshuffle_apps.rs

@@ -511,6 +511,7 @@ mod tests {
     fn install_new_c_app() {
         let settings: &BoardSettings = &BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 512,
             ram_start_address: 0x20000000,
@@ -568,6 +569,7 @@ mod tests {
     fn install_new_rust_app() {
         let settings: &BoardSettings = &BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 512,
             ram_start_address: 0x20000000,
@@ -604,6 +606,7 @@ mod tests {
     fn install_more_rust_apps() {
         let settings: &BoardSettings = &BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 512,
             ram_start_address: 0x20000000,
@@ -678,6 +681,7 @@ mod tests {
     fn insert_c_app_between_rust_apps() {
         let settings: &BoardSettings = &BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 512,
             ram_start_address: 0x20000000,

tockloader-lib/src/command_impl/serial/io.rs

@@ -84,7 +84,10 @@ impl IOCommands for SerialConnection {
 
         ping_bootloader_and_wait_for_response(stream).await?;
 
-        let system_attributes = SystemAttributes::read_system_attributes(self).await?;
+        let flash_address = self.get_settings().flash_address;
+        let start_address = self.get_settings().start_address;
+        let system_attributes =
+            SystemAttributes::read_system_attributes(self, flash_address, start_address).await?;
         Ok(system_attributes)
     }
 }

tockloader-lib/src/known_boards.rs

@@ -24,6 +24,7 @@ impl KnownBoard for NucleoF4 {
     fn get_settings(&self) -> BoardSettings {
         BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x08000000,
             start_address: 0x08040000,
             page_size: 512,
             ram_start_address: 0x20000000,
@@ -48,6 +49,7 @@ impl KnownBoard for MicrobitV2 {
     fn get_settings(&self) -> BoardSettings {
         BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 512,
             ram_start_address: 0x20000000,
@@ -72,6 +74,7 @@ impl KnownBoard for Nrf52840dk {
     fn get_settings(&self) -> BoardSettings {
         BoardSettings {
             arch: Some("cortex-m4".to_string()),
+            flash_address: 0x00000000,
             start_address: 0x00040000,
             page_size: 4096,
             ram_start_address: 0x20008000,
@@ -96,7 +99,8 @@ impl KnownBoard for NucleoU545ReQ {
     fn get_settings(&self) -> BoardSettings {
         BoardSettings {
             arch: Some("cortex-m4".to_string()),
-            start_address: 0x08000000,
+            flash_address: 0x08000000,
+            start_address: 0x08040000,
             page_size: 8192,
             ram_start_address: 0x20000000,
         }