Fix parsing xml from firehose

[gfabiano]

Fix parsing xml from firehose when multiple xml are sent sequentially on the same data transfer.

Loader sent. Hack away!
Firehose failed. Resetting the board to edl, try again.
RECV: Element { prefix: None, namespace: None, namespaces: None, name: "response", attributes: {"value": "ACK", "rawmode": "false"}, children: [] }
Error: Malformed XML. 4:17 Invalid processing instruction: <?xml - "<?xml"-like PI is only valid at the beginning of the document

[quic-kdybcio]

Huh, interesting.. the spec doesn't really enforce there's only a single XML per transfer, but this hasn't been an issue on devices I've tested so far.

Could you share some details about your setup?

[gfabiano]

Hi @quic-kdybcio !

Yes my board is based on sa8155p, when I try to flash with this tool I noticed that it failed and I investigated, what i noticed is that I received multiple xml on one transfer. I do not know the spec of firehose and I'm not so expert on that. Maybe is an edge case. If you need some specific test I can try.

QDL and QFIL never failed by the way so i think that they handle that.

[quic-kdybcio]

@gfabiano I came up with this diff to reduce copying and loosen the encoding/whitespace requirements, I only compile-tested it - can you give it a shot?

index b15029b89f04..16960e8e8930 100644
--- a/qdl/src/lib.rs
+++ b/qdl/src/lib.rs
@@ -9,6 +9,7 @@ use serial::setup_serial_device;
 use std::cmp::min;
 use std::io::Read;
 use std::io::Write;
+use std::str;
 use std::str::FromStr;
 use types::FirehoseResetMode;
 use types::FirehoseStatus;
@@ -96,15 +97,13 @@ pub fn firehose_read<T: Read + Write + QdlChan>(

         got_any_data = true;

-        let xml_declaration = r#"<?xml version="1.0" encoding="UTF-8" ?>"#;
         let xml_fragments: Vec<&str> = str::from_utf8(&buf[..bytes_read])?
-            .split(xml_declaration)
+            .split_inclusive("<?xml")
             .filter(|s| !s.is_empty())
             .collect();

         for fragment in xml_fragments.iter() {
-            let full_xml_string = format!("{}{}", xml_declaration, fragment);
-            let xml = xmltree::Element::parse(full_xml_string.as_bytes())?;
+            let xml = xmltree::Element::parse(fragment.as_bytes())?;

             if xml.name != "data" {
                 // TODO: define a more verbose level
@@ -113,7 +112,7 @@ pub fn firehose_read<T: Read + Write + QdlChan>(
                 }
                 bail!("Got a firehose packet without a data tag");
             }
-
+
             // The spec expects there's always a single node only
             if let Some(XMLNode::Element(e)) = xml.children.first() {
                 // Check for a 'log' node and print out the message

[gfabiano]

Yes for sure, I fetch and try to flash something

[gfabiano]

Hi @quic-kdybcio,

split_inclusive unfortunately add the delimiter not in the right place. So I modified the implementation to use indexes and slices to better optimize and avoid unintended copies. I flashed without problems on my board.

Give me some feedback if it is ok or it needs reworks.

[gfabiano]

I solved the feedback as requested

[quic-kdybcio]

Squashed your commits and resolved a cosmetic merge conflit - now just waiting for CI to run