kern: implement SvcGetThreadContext3

libraries/libmesosphere/include/mesosphere/arch/arm64/kern_k_exception_context.hpp

@@ -22,7 +22,8 @@ namespace ams::kern::arch::arm64 {
         u64 x[(30 - 0) + 1];
         u64 sp;
         u64 pc;
-        u64 psr;
+        u32 psr;
+        u32 write;
         u64 tpidr;
         u64 reserved;
     };

libraries/libmesosphere/include/mesosphere/arch/arm64/kern_k_thread_context.hpp

@@ -74,7 +74,11 @@ namespace ams::kern::arch::arm64 {
 
             void CloneFpuStatus();
 
+            const u128 *GetFpuRegisters() const { return this->fpu_registers; }
+
             /* TODO: More methods (especially FPU management) */
     };
 
+    void GetUserContext(ams::svc::ThreadContext *out, const KThread *thread);
+
 }

libraries/libmesosphere/include/mesosphere/kern_k_thread.hpp

@@ -270,6 +270,11 @@ namespace ams::kern {
                 return this->GetStackParameters().is_in_exception_handler;
             }
 
+            ALWAYS_INLINE bool IsCallingSvc() const {
+                MESOSPHERE_ASSERT_THIS();
+                return this->GetStackParameters().is_calling_svc;
+            }
+
             ALWAYS_INLINE void RegisterDpc(DpcFlag flag) {
                 this->GetStackParameters().dpc_flags |= flag;
             }
@@ -455,6 +460,7 @@ namespace ams::kern {
             void Continue();
 
             Result SetActivity(ams::svc::ThreadActivity activity);
+            Result GetThreadContext3(ams::svc::ThreadContext *out);
 
             void ContinueIfHasKernelWaiters() {
                 if (this->GetNumKernelWaiters() > 0) {

libraries/libmesosphere/include/mesosphere/kern_k_thread_context.hpp

@@ -20,6 +20,8 @@
 
     namespace ams::kern {
         using ams::kern::arch::arm64::KThreadContext;
+
+        using ams::kern::arch::arm64::GetUserContext;
     }
 #else
     #error "Unknown architecture for KThreadContext"