From 24487b21b7df00bd35c24889b9e85dc4d90128aa Mon Sep 17 00:00:00 2001
From: Simon Gellis <simongellis@gmail.com>
Date: Wed, 1 Jan 2025 14:56:54 -0500
Subject: [PATCH] Support pausing and resuming

---
 src/gdbserver.rs | 66 ++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 58 insertions(+), 8 deletions(-)

diff --git a/src/gdbserver.rs b/src/gdbserver.rs
index 2d90c11..4f0a78d 100644
--- a/src/gdbserver.rs
+++ b/src/gdbserver.rs
@@ -71,7 +71,6 @@ async fn run_server(
     port: u16,
     status: &Mutex<GdbServerStatus>,
 ) {
-    client.send_command(EmulatorCommand::Pause);
     let Some(stream) = try_connect(port, status).await else {
         return;
     };
@@ -142,43 +141,88 @@ impl GdbConnection {
     }
     async fn run(mut self) -> Result<()> {
         println!("Connected for {}", self.sim_id);
-        self.client.send_command(EmulatorCommand::Resume);
+        self.client.send_command(EmulatorCommand::Pause);
         loop {
             let message = self.read_message().await?;
             println!("received {:?}", message);
 
-            let mut res = ResponseWriter::new(&mut self.stream_out);
-            res.init(self.ack_messages).await?;
+            //let mut res = ResponseWriter::new(&mut self.stream_out);
+            //res.init(self.ack_messages).await?;
 
             let body = match &message {
                 Message::String(str) => str.as_str(),
                 Message::Signal => {
-                    // TODO: handle this
+                    self.client.send_command(EmulatorCommand::Pause);
+                    let mut res = self.respond().await?;
+                    res.write_str("T05;thread:p1.t1;threads:p1.t1;reason:trap;")
+                        .await?;
                     res.send().await?;
                     continue;
                 }
             };
 
             if body == "QStartNoAckMode" {
+                let mut res = ResponseWriter::new(&mut self.stream_out);
+                res.init(self.ack_messages).await?;
                 self.ack_messages = false;
                 res.send_ok().await?;
             } else if body.starts_with("qSupported:") {
+                let mut res = self.respond().await?;
                 res.write_str("multiprocess+;swbreak+;vContSupported+")
                     .await?;
                 res.send().await?;
-            } else if body == "QThreadSuffixSupported" || body == "QListThreadsInStopReply" {
+            } else if body == "QThreadSuffixSupported"
+                || body == "QListThreadsInStopReply"
+                || body == "QEnableErrorStrings"
+            {
+                let res = self.respond().await?;
                 res.send_ok().await?;
-            } else if body == "qHostInfo" || body == "qProcessInfo" {
+            } else if body == "qHostInfo" {
+                let mut res = self.respond().await?;
                 res.write_str(&format!(
                     "triple:{};endian:little;ptrsize:4;",
                     hex::encode("v810-unknown-vb")
                 ))
                 .await?;
                 res.send().await?;
+            } else if body == "qProcessInfo" {
+                let mut res = self.respond().await?;
+                res.write_str(&format!(
+                    "pid:1;triple:{};endian:little;ptrsize:4;",
+                    hex::encode("v810-unknown-vb")
+                ))
+                .await?;
+                res.send().await?;
+            } else if body == "vCont?" {
+                let mut res = self.respond().await?;
+                res.write_str("vCont;c;").await?;
+                res.send().await?;
+            } else if body == "qC" {
+                // The v810 has no threads, so report that the "current thread" is 1.
+                let mut res = self.respond().await?;
+                res.write_str("QCp1.t1").await?;
+                res.send().await?;
+            } else if body == "qfThreadInfo" {
+                let mut res = self.respond().await?;
+                res.write_str("mp1.t1").await?;
+                res.send().await?;
+            } else if body == "qsThreadInfo" {
+                let mut res = self.respond().await?;
+                res.write_str("l").await?;
+                res.send().await?;
             } else if body == "k" {
-                return Ok(());
+                bail!("debug process was killed");
+            } else if body == "?" {
+                let mut res = self.respond().await?;
+                res.write_str("T00;thread:p1.t1;threads:p1.t1;").await?;
+                res.send().await?;
+            } else if body == "c" || body.starts_with("vCont;c:") {
+                // Continue running the game until we're interrupted again
+                self.client.send_command(EmulatorCommand::Resume);
+                continue;
             } else {
                 // unrecognized command
+                let res = self.respond().await?;
                 res.send().await?;
             }
         }
@@ -235,6 +279,12 @@ impl GdbConnection {
     async fn read_byte(&mut self) -> std::io::Result<u8> {
         self.stream_in.read_u8().await
     }
+
+    async fn respond(&mut self) -> std::io::Result<ResponseWriter<'_>> {
+        let mut res = ResponseWriter::new(&mut self.stream_out);
+        res.init(self.ack_messages).await?;
+        Ok(res)
+    }
 }
 
 struct ResponseWriter<'a> {