checkpoint

1 files changed, 73 insertions, 0 deletions

diff --git a/src/libs/reference_decoder/sim86_lib.cpp b/src/libs/reference_decoder/sim86_lib.cpp
new file mode 100644
index 0000000..6971eb2
--- /dev/null
+++ b/src/libs/reference_decoder/sim86_lib.cpp
@@ -0,0 +1,73 @@
+/* ========================================================================
+
+   (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved.
+   
+   This software is provided 'as-is', without any express or implied
+   warranty. In no event will the authors be held liable for any damages
+   arising from the use of this software.
+   
+   Please see https://computerenhance.com for more information
+   
+   ======================================================================== */
+
+#define assert(...)
+
+#include "sim86.h"
+
+#include "sim86_instruction.h"
+#include "sim86_instruction_table.h"
+#include "sim86_memory.h"
+#include "sim86_decode.h"
+
+#include "sim86_instruction.cpp"
+#include "sim86_instruction_table.cpp"
+#include "sim86_memory.cpp"
+#include "sim86_decode.cpp"
+#include "sim86_text_table.cpp"
+
+extern "C" u32 Sim86_GetVersion(void)
+{
+    u32 Result = SIM86_VERSION;
+    return Result;
+}
+
+extern "C" void Sim86_Decode8086Instruction(u32 SourceSize, u8 *Source, instruction *Dest)
+{
+    instruction_table Table = Get8086InstructionTable();
+    
+    // NOTE(casey): The 8086 decoder requires the ability to read up to 15 bytes (the maximum
+    // allowable instruction size)
+    assert(Table.MaxInstructionByteCount == 15);
+    u8 GuardBuffer[16] = {};
+    if(SourceSize < Table.MaxInstructionByteCount)
+    {
+        // NOTE(casey): I replaced the memcpy here with a manual copy to make it easier for
+        // people compiling on things like WebAssembly who do not want to use Emscripten.
+        for(u32 I = 0; I < SourceSize; ++I)
+        {
+            GuardBuffer[I] = Source[I];
+        }
+        
+        Source = GuardBuffer;
+    }
+    
+    segmented_access At = FixedMemoryPow2(4, Source);
+    *Dest = DecodeInstruction(Table, At);
+}
+
+extern "C" char const *Sim86_RegisterNameFromOperand(register_access *RegAccess)
+{
+    char const *Result = GetRegName(*RegAccess);
+    return Result;
+}
+
+extern "C" char const *Sim86_MnemonicFromOperationType(operation_type Type)
+{
+    char const *Result = GetMnemonic(Type);
+    return Result;
+}
+
+extern "C" void Sim86_Get8086InstructionTable(instruction_table *Dest)
+{
+    *Dest = Get8086InstructionTable();
+}
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