Impl monitor reset and reset halt commands

3 files changed, 60 insertions, 1 deletions

diff --git a/emulator.cpp b/emulator.cpp
index 051c6db..5dd266a 100644
--- a/emulator.cpp
+++ b/emulator.cpp
@@ -95,11 +95,20 @@ static int setup_socket(uint16_t port)
     return socket_fd;
 }
 
+static inline bool IsReset(const std::string& command)
+{
+    if (command == "reset") return true;
+    if (command == "reset halt") return true;
+    if (command == "system_reset") return true;
+    return false;
+}
+
 static std::string CreateResponse(
         M68KDebuggingControl& m68k_debug,
         const GDBRemote::Packet& packet)
 {
     using namespace GDBRemote;
+    // TODO use switch-case
     if (0) {
     } else if (packet.type == PacketType::kQueryHaltReason) {
         return "S05"; // TODO real reason
@@ -116,6 +125,20 @@ static std::string CreateResponse(
         return "OK";
     } else if (packet.type == PacketType::kQueryAttached) {
         return "1";
+    } else if (packet.type == PacketType::kQueryRcmd) {
+        const auto * const packet_data =
+            static_cast<const PacketDataRcmd*>(packet.data.get());
+        if (IsReset(packet_data->data)) {
+            m68k_pulse_reset();
+            // I don't want to skip reset cycles here, because GDB does not
+            // re-read registers every time, and if we skip reset cycles here,
+            // the consequent "stepi" in gdb will end up on second instruction
+            // of reset handler. If we don't skip reset cycles, the first
+            // "stepi" after "monitor reset" will land us on the first
+            // instruction in reset handler - I'd prefer this exact behavior for
+            // now.
+            return "OK";
+        }
     } else if (packet.type == PacketType::kInterrupt) {
         return "OK";
     } else if (packet.type == PacketType::kSetBreakpoint) {
@@ -356,6 +379,7 @@ int main(int argc, char* argv[])
     m68k_init();
     m68k_set_cpu_type(M68K_CPU_TYPE_68000);
     m68k_pulse_reset();
+    m68k_execute(1); // Skip reset cycles
 
     emulator(g_m68k_debug);
     while (0)
diff --git a/gdbremote_parser.cpp b/gdbremote_parser.cpp
index b9115be..98533c5 100644
--- a/gdbremote_parser.cpp
+++ b/gdbremote_parser.cpp
@@ -79,6 +79,15 @@ struct Token {
     }
 };
 
+static std::string DecodeBinaryHex(const std::string& data_hex)
+{
+    std::string data(data_hex.size()/2, '\0');
+    for (size_t i = 0; i < data.size(); i++) {
+        data[i] = Utils::ParseByteFromHexChars(data_hex[i * 2], data_hex[i * 2 + 1]);
+    }
+    return data;
+}
+
 struct Command {
     std::string name;
     Packet (*parse)(const std::vector<Token>&&);
@@ -122,6 +131,22 @@ struct Command {
     {
         return Packet{PacketType::kQueryTraceStatus};
     }
+    static Packet parseQueryRcmd(const std::vector<Token>&& tokens)
+    {
+        if (tokens.size() < 3)
+            return Packet::None();
+        if (tokens[1].type != TokenType::kSeparatorComma)
+            return Packet::None();
+        if (tokens[2].type != TokenType::kHexNumeric)
+            return Packet::None();
+        const std::string& data_encoded = tokens[2].data;
+        const std::string data = DecodeBinaryHex(data_encoded);
+        printf("%s\n", data.c_str());
+        return Packet{
+            PacketType::kQueryRcmd,
+            std::make_unique<const PacketDataRcmd>(std::move(data)),
+        };
+    }
     static Packet parseSetThreadForCont(const std::vector<Token>&&)
     {
         // TODO arguments
@@ -146,7 +171,7 @@ struct Command {
     }
     static Packet parseContinueVCont(const std::vector<Token>&& tokens)
     {
-        const std::string first_arg = tokens[1].data;
+        const std::string first_arg = tokens.size() > 1 ? tokens[1].data : "";
         // Check if it is "vCont?" command
         if (first_arg == "?") {
             return Packet{PacketType::kContinueAskSupported};
@@ -260,6 +285,7 @@ static const Command commands[] = {
     { "qL",                 Command::parseQueryRTOSThreadInfo },
     { "qAttached",          Command::parseQueryAttached },
     { "qTStatus",           Command::parseQueryTraceStatus },
+    { "qRcmd",              Command::parseQueryRcmd },
     { "Hc",                 Command::parseSetThreadForCont },
     { "Hg",                 Command::parseSetThreadForOps },
     { "vMustReplyEmpty",    Command::parseMustReplyEmpty },
diff --git a/gdbremote_parser.hpp b/gdbremote_parser.hpp
index 370e8cc..a6d76fc 100644
--- a/gdbremote_parser.hpp
+++ b/gdbremote_parser.hpp
@@ -51,6 +51,7 @@ enum class PacketType: int {
     kQueryRTOSThreadInfo,
     kQueryAttached,
     kQueryTraceStatus,
+    kQueryRcmd,
     kSetThreadForCont,
     kSetThreadForOps,
     kVMustReplyEmpty,
@@ -94,6 +95,12 @@ struct PacketDataWriteMemory: public PacketData {
     virtual ~PacketDataWriteMemory() {}
 };
 
+struct PacketDataRcmd: public PacketData {
+    PacketDataRcmd(const std::string&& a_data): data(std::move(a_data)) {}
+    std::string data{};
+    virtual ~PacketDataRcmd() {}
+};
+
 enum class BreakpointType: uint32_t {
     kMin = 0,
     kSoftwareBreakpoint = 0,
@@ -146,6 +153,8 @@ struct Packet {
             return "qAttached";
         case PacketType::kQueryTraceStatus:
             return "qTStatus";
+        case PacketType::kQueryRcmd:
+            return "qRcmd";
         case PacketType::kSetThreadForCont:
             return "Hc";
         case PacketType::kSetThreadForOps: