From 4fd456e1583a4c8686c8de87c2aeb1eb78125be1 Mon Sep 17 00:00:00 2001
From: David Guillen Fandos
Date: Wed, 5 May 2021 02:20:00 +0200
Subject: Adding Code Breaker cheat support

This works on both interpreter and dynarec.
Tested in MIPS, ARM and x86, still needs some more testing, some edge
cases can be buggy.
---
 psp/mips_emit.h |  7 +++++++
 psp/mips_stub.S | 13 +++++++++++++
 2 files changed, 20 insertions(+)

(limited to 'psp')

diff --git a/psp/mips_emit.h b/psp/mips_emit.h
index 12685e8..174fee5 100644
--- a/psp/mips_emit.h
+++ b/psp/mips_emit.h
@@ -44,6 +44,7 @@ void mips_indirect_branch_dual(u32 address);
 u32 execute_read_cpsr();
 u32 execute_read_spsr();
 void execute_swi(u32 pc);
+void mips_cheat_hook();
 
 u32 execute_spsr_restore(u32 address);
 void execute_store_cpsr(u32 new_cpsr, u32 store_mask);
@@ -2422,6 +2423,12 @@ u32 execute_store_cpsr_body(u32 _cpsr, u32 store_mask, u32 address)
   generate_indirect_branch_cycle_update(dual);                                \
 }                                                                             \
 
+#define thumb_process_cheats()                                                \
+  generate_function_call(mips_cheat_hook);
+
+#define arm_process_cheats()                                                  \
+  generate_function_call(mips_cheat_hook);
+
 #ifdef TRACE_INSTRUCTIONS
   void trace_instruction(u32 pc)
   {
diff --git a/psp/mips_stub.S b/psp/mips_stub.S
index 08151db..786dc9e 100644
--- a/psp/mips_stub.S
+++ b/psp/mips_stub.S
@@ -44,6 +44,7 @@
 .global init_emitter
 .global mips_lookup_pc
 .global smc_write
+.global mips_cheat_hook
 
 .global write_io_epilogue
 .global memory_map_read
@@ -256,6 +257,17 @@ mips_update_gba:
   nop
 
 
+# Processes cheats whenever we hit the master PC
+mips_cheat_hook:
+  sw $ra, REG_SAVE2($16)
+  save_registers
+  cfncall process_cheats, 8
+  lw $ra, REG_SAVE2($16)
+  restore_registers
+  jr $ra
+  nop
+
+
 # Loads the main context and returns to it.
 # ARM regs must be saved before branching here
 return_to_main:
@@ -649,6 +661,7 @@ fnptrs:
   .long set_cpu_mode                   # 5
   .long execute_spsr_restore_body      # 6
   .long execute_store_cpsr_body        # 7
+  .long process_cheats                 # 8
 
 #if !defined(HAVE_MMAP)
 
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