GDB Stub Improvements (#508)

* GDB Stub should work now.

* Applied clang-format.

* Replaced htonll with swap64.

* Tidy up.

2 files changed, 41 insertions, 1 deletions

diff --git a/src/core/arm/unicorn/arm_unicorn.cpp b/src/core/arm/unicorn/arm_unicorn.cpp
index c0cc62f03..ce6c5616d 100644
--- a/src/core/arm/unicorn/arm_unicorn.cpp
+++ b/src/core/arm/unicorn/arm_unicorn.cpp
@@ -35,6 +35,17 @@ LoadDll LoadDll::g_load_dll;
         }                                                                                          \
     } while (0)
 
+static void CodeHook(uc_engine* uc, uint64_t address, uint32_t size, void* user_data) {
+    GDBStub::BreakpointAddress bkpt =
+        GDBStub::GetNextBreakpointFromAddress(address, GDBStub::BreakpointType::Execute);
+    if (GDBStub::IsMemoryBreak() ||
+        (bkpt.type != GDBStub::BreakpointType::None && address == bkpt.address)) {
+        auto core = static_cast<ARM_Unicorn*>(user_data);
+        core->RecordBreak(bkpt);
+        uc_emu_stop(uc);
+    }
+}
+
 static void InterruptHook(uc_engine* uc, u32 intNo, void* user_data) {
     u32 esr{};
     CHECKED(uc_reg_read(uc, UC_ARM64_REG_ESR, &esr));
@@ -67,6 +78,10 @@ ARM_Unicorn::ARM_Unicorn() {
     uc_hook hook{};
     CHECKED(uc_hook_add(uc, &hook, UC_HOOK_INTR, (void*)InterruptHook, this, 0, -1));
     CHECKED(uc_hook_add(uc, &hook, UC_HOOK_MEM_INVALID, (void*)UnmappedMemoryHook, this, 0, -1));
+    if (GDBStub::IsServerEnabled()) {
+        CHECKED(uc_hook_add(uc, &hook, UC_HOOK_CODE, (void*)CodeHook, this, 0, -1));
+        last_bkpt_hit = false;
+    }
 }
 
 ARM_Unicorn::~ARM_Unicorn() {
@@ -155,7 +170,11 @@ void ARM_Unicorn::SetTlsAddress(VAddr base) {
 }
 
 void ARM_Unicorn::Run() {
-    ExecuteInstructions(std::max(CoreTiming::GetDowncount(), 0));
+    if (GDBStub::IsServerEnabled()) {
+        ExecuteInstructions(std::max(4000000, 0));
+    } else {
+        ExecuteInstructions(std::max(CoreTiming::GetDowncount(), 0));
+    }
 }
 
 void ARM_Unicorn::Step() {
@@ -168,6 +187,18 @@ void ARM_Unicorn::ExecuteInstructions(int num_instructions) {
     MICROPROFILE_SCOPE(ARM_Jit);
     CHECKED(uc_emu_start(uc, GetPC(), 1ULL << 63, 0, num_instructions));
     CoreTiming::AddTicks(num_instructions);
+    if (GDBStub::IsServerEnabled()) {
+        if (last_bkpt_hit) {
+            uc_reg_write(uc, UC_ARM64_REG_PC, &last_bkpt.address);
+        }
+        Kernel::Thread* thread = Kernel::GetCurrentThread();
+        SaveContext(thread->context);
+        if (last_bkpt_hit) {
+            last_bkpt_hit = false;
+            GDBStub::Break();
+        }
+        GDBStub::SendTrap(thread, 5);
+    }
 }
 
 void ARM_Unicorn::SaveContext(ARM_Interface::ThreadContext& ctx) {
@@ -233,3 +264,8 @@ void ARM_Unicorn::PrepareReschedule() {
 }
 
 void ARM_Unicorn::ClearInstructionCache() {}
+
+void ARM_Unicorn::RecordBreak(GDBStub::BreakpointAddress bkpt) {
+    last_bkpt = bkpt;
+    last_bkpt_hit = true;
+}
diff --git a/src/core/arm/unicorn/arm_unicorn.h b/src/core/arm/unicorn/arm_unicorn.h
index b99b58e4c..a482a2aa3 100644
--- a/src/core/arm/unicorn/arm_unicorn.h
+++ b/src/core/arm/unicorn/arm_unicorn.h
@@ -7,6 +7,7 @@
 #include <unicorn/unicorn.h>
 #include "common/common_types.h"
 #include "core/arm/arm_interface.h"
+#include "core/gdbstub/gdbstub.h"
 
 class ARM_Unicorn final : public ARM_Interface {
 public:
@@ -35,7 +36,10 @@ public:
     void Step() override;
     void ClearInstructionCache() override;
     void PageTableChanged() override{};
+    void RecordBreak(GDBStub::BreakpointAddress bkpt);
 
 private:
     uc_engine* uc{};
+    GDBStub::BreakpointAddress last_bkpt{};
+    bool last_bkpt_hit;
 };