1 files changed, 98 insertions, 0 deletions
diff --git a/tools/nx2/gdbrsp.py b/tools/nx2/gdbrsp.py
new file mode 100644
index 0000000000..03ffbd00f5
--- /dev/null
+++ b/tools/nx2/gdbrsp.py
@@ -0,0 +1,98 @@
+#!/usr/bin/env python3
+# Minimal GDB remote-serial-protocol client for Eden's gdbstub (AArch64 guests).
+# Usage: gdbrsp.py <port> <script>
+# Script lines:  break <hexaddr> | unbreak <hexaddr> | continue | regs | mem <hexaddr|xN> <len> | bt <hexaddr|sp> <count>
+#                | quit
+import socket
+import struct
+import sys
+
+REGS = [f"x{i}" for i in range(31)] + ["sp", "pc", "cpsr"]
+
+
+class Rsp:
+    def __init__(self, port):
+        import time
+        for _ in range(240):  # wait up to ~2 min for the stub to listen
+            try:
+                self.s = socket.create_connection(("127.0.0.1", port), timeout=600)
+                break
+            except OSError:
+                time.sleep(0.5)
+        else:
+            raise SystemExit("gdbstub not reachable")
+        self.buf = b""
+
+    def _read_packet(self):
+        while True:
+            while b"$" not in self.buf or b"#" not in self.buf[self.buf.index(b"$"):]:
+                chunk = self.s.recv(65536)
+                if not chunk:
+                    raise EOFError
+                self.buf += chunk
+            start = self.buf.index(b"$")
+            end = self.buf.index(b"#", start)
+            if len(self.buf) < end + 3:
+                self.buf += self.s.recv(65536)
+                continue
+            data = self.buf[start + 1:end]
+            self.buf = self.buf[end + 3:]
+            self.s.sendall(b"+")
+            return data.decode(errors="replace")
+
+    def cmd(self, c):
+        pkt = c.encode()
+        self.s.sendall(b"$" + pkt + b"#" + f"{sum(pkt) & 0xff:02x}".encode())
+        return self._read_packet()
+
+    def regs(self):
+        r = self.cmd("g")
+        vals = {}
+        off = 0
+        for name in REGS:
+            n = 8 if name != "cpsr" else 4
+            if off + n * 2 > len(r):
+                break
+            vals[name] = int.from_bytes(bytes.fromhex(r[off:off + n * 2]), "little")
+            off += n * 2
+        return vals
+
+    def mem(self, addr, length):
+        r = self.cmd(f"m{addr:x},{length:x}")
+        try:
+            return bytes.fromhex(r)
+        except ValueError:
+            return b""
+
+
+def main():
+    rsp = Rsp(int(sys.argv[1]))
+    print("halt reason:", rsp.cmd("?"))
+    regs = {}
+    for line in open(sys.argv[2]):
+        parts = line.split()
+        if not parts or parts[0].startswith("#"):
+            continue
+        op = parts[0]
+        if op == "break":
+            print("break", parts[1], "->", rsp.cmd(f"Z0,{int(parts[1], 16):x},4"))
+        elif op == "unbreak":
+            print("unbreak", parts[1], "->", rsp.cmd(f"z0,{int(parts[1], 16):x},4"))
+        elif op == "continue":
+            print("stop:", rsp.cmd("c"))
+        elif op == "regs":
+            regs = rsp.regs()
+            print(" ".join(f"{k}={v:#x}" for k, v in regs.items()))
+        elif op == "mem":
+            a = regs[parts[1]] if parts[1] in regs else int(parts[1], 16)
+            data = rsp.mem(a, int(parts[2], 0))
+            for i in range(0, len(data), 16):
+                words = [struct.unpack_from("<Q", data, i + j)[0] for j in range(0, min(16, len(data) - i) - 7, 8)]
+                print(f"  {a + i:#x}: " + " ".join(f"{w:016x}" for w in words))
+        elif op == "quit":
+            break
+    rsp.s.close()
+
+
+if __name__ == "__main__":
+    main()