From 08a2f02a7cc2d6176ef2fd4658870a3c37504b42 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Thu, 4 Apr 2019 12:23:51 -0700
Subject: [PATCH] dmnt-cheat: Add Save/Restore register mask opcode

---
 stratosphere/dmnt/source/dmnt_cheat_vm.cpp | 36 ++++++++++++++++++++++
 stratosphere/dmnt/source/dmnt_cheat_vm.hpp |  7 +++++
 2 files changed, 43 insertions(+)

diff --git a/stratosphere/dmnt/source/dmnt_cheat_vm.cpp b/stratosphere/dmnt/source/dmnt_cheat_vm.cpp
index cc1c3820f..162e60c33 100644
--- a/stratosphere/dmnt/source/dmnt_cheat_vm.cpp
+++ b/stratosphere/dmnt/source/dmnt_cheat_vm.cpp
@@ -194,6 +194,13 @@ void DmntCheatVm::LogOpcode(const CheatVmOpcode *opcode) {
             this->LogToDebugFile("Src Idx:   %x\n", opcode->save_restore_reg.src_index);
             this->LogToDebugFile("Is Save:   %d\n", opcode->save_restore_reg.is_save);
             break;
+        case CheatVmOpcodeType_SaveRestoreRegisterMask: 
+            this->LogToDebugFile("Opcode: Save or Restore Register Mask\n");
+            this->LogToDebugFile("Is Save:   %d\n", opcode->save_restore_regmask.is_save);
+            for (size_t i = 0; i < NumRegisters; i++) {
+                this->LogToDebugFile("Act[%02x]:   %d\n", i, opcode->save_restore_regmask.should_save_or_restore[i]);
+            }
+            break;
         default:
             this->LogToDebugFile("Unknown opcode: %x\n", opcode->opcode);
             break;
@@ -481,6 +488,18 @@ bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode *out) {
                 opcode.save_restore_reg.is_save = ((first_dword >> 4) & 0xF) != 0;
             }
             break;
+        case CheatVmOpcodeType_SaveRestoreRegisterMask:
+            {
+                /* C2x0XXXX */
+                /* C2 = opcode 0xC2 */
+                /* x = 1 if saving, 0 if restoring. */
+                /* X = 16-bit bitmask, bit i --> save or restore register i. */
+                opcode.save_restore_regmask.is_save = ((first_dword >> 20) & 0xF) != 0;
+                for (size_t i = 0; i < NumRegisters; i++) {
+                    opcode.save_restore_regmask.should_save_or_restore[i] = (first_dword & (1u << i)) != 0;
+                }
+            }
+            break;
         case CheatVmOpcodeType_ExtendedWidth:
         default:
             /* Unrecognized instruction cannot be decoded. */
@@ -996,6 +1015,23 @@ void DmntCheatVm::Execute(const CheatProcessMetadata *metadata) {
                     this->registers[cur_opcode.save_restore_reg.dst_index] = this->saved_values[cur_opcode.save_restore_reg.src_index];
                 }
                 break;
+            case CheatVmOpcodeType_SaveRestoreRegisterMask:
+                /* Save or restore register mask. */
+                u64 *src;
+                u64 *dst;
+                if (cur_opcode.save_restore_regmask.is_save) {
+                    src = this->registers;
+                    dst = this->saved_values;
+                } else {
+                    src = this->registers;
+                    dst = this->saved_values;
+                }
+                for (size_t i = 0; i < NumRegisters; i++) {
+                    if (cur_opcode.save_restore_regmask.should_save_or_restore[i]) {
+                        dst[i] = src[i];
+                    }
+                }
+                break;
             default:
                 /* By default, we do a no-op. */
                 break;
diff --git a/stratosphere/dmnt/source/dmnt_cheat_vm.hpp b/stratosphere/dmnt/source/dmnt_cheat_vm.hpp
index 5689f8fd8..4ab1b1511 100644
--- a/stratosphere/dmnt/source/dmnt_cheat_vm.hpp
+++ b/stratosphere/dmnt/source/dmnt_cheat_vm.hpp
@@ -44,6 +44,7 @@ enum CheatVmOpcodeType : u32 {
     /* Extended width opcodes. */
     CheatVmOpcodeType_BeginRegisterConditionalBlock = 0xC0,
     CheatVmOpcodeType_SaveRestoreRegister = 0xC1,
+    CheatVmOpcodeType_SaveRestoreRegisterMask = 0xC2,
 };
 
 enum MemoryAccessType : u32 {
@@ -198,6 +199,11 @@ struct SaveRestoreRegisterOpcode {
     bool is_save;
 };
 
+struct SaveRestoreRegisterMaskOpcode {
+    bool is_save;
+    bool should_save_or_restore[0x10];
+};
+
 struct CheatVmOpcode {
     CheatVmOpcodeType opcode;
     bool begin_conditional_block;
@@ -215,6 +221,7 @@ struct CheatVmOpcode {
         StoreRegisterToAddressOpcode str_register;
         BeginRegisterConditionalOpcode begin_reg_cond;
         SaveRestoreRegisterOpcode save_restore_reg;
+        SaveRestoreRegisterMaskOpcode save_restore_regmask;
     };
 };