Fix Crc after comptool

2 files changed, 42 insertions, 2 deletions

diff --git a/src/preprocess/CompTool.cpp b/src/preprocess/CompTool.cpp
index f453050..d310e35 100644
--- a/src/preprocess/CompTool.cpp
+++ b/src/preprocess/CompTool.cpp
@@ -4,6 +4,7 @@
 #include "lib/binarytools/BinaryReader.h"
 #include <fstream>
 #include <cstring>
+#include <stdexcept>
 
 uint32_t CompTool::FindFileTable(std::vector<uint8_t>& rom) {
     uint8_t query_one[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x50, 0x00, 0x00, 0x00, 0x00 };
@@ -22,6 +23,39 @@ uint32_t CompTool::FindFileTable(std::vector<uint8_t>& rom) {
     throw std::runtime_error("Failed to find file table");
 }
 
+#define ROL(i, b) ((i << (b)) | (i >> (32 - (b))))
+
+std::pair<uint32_t, uint32_t> CompTool::CalculateCRCs(LUS::BinaryWriter& decompFile)
+{
+    uint32_t start = 0x1000;
+    uint32_t end = 0x101000;
+    LUS::BinaryReader readFile(decompFile.GetStream());
+    uint32_t t1, t2, t3, t4, t5, t6;
+
+    // Todo: Implement other bootcodes
+    t1 = t2 = t3 = t4 = t5 = t6 = sCrcSeed;
+
+    readFile.SetEndianness(Torch::Endianness::Big);
+    readFile.Seek(start, LUS::SeekOffsetType::Start);
+
+    for (size_t i = start; i < end; i += sizeof(uint32_t)) {
+        uint32_t d = readFile.ReadUInt32();
+        uint32_t r = ROL(d, d & 0x1F);
+
+        if ((t6 + d) < t6) {
+            t4 = (t4 + 1);
+        }
+
+        t3 ^= d;
+        t6 += d;
+        t2 ^= ((t2 > d) ? r : (t6 ^ d));
+        t5 += r;
+        t1 += (t5 ^ d);
+    }
+
+    return std::make_pair((uint32_t)(t6 ^ t4 ^ t3), (uint32_t)(t5 ^ t2 ^ t1));
+}
+
 std::vector<uint8_t> CompTool::Decompress(std::vector<uint8_t> rom){
     LUS::BinaryReader basefile((char*) rom.data(), rom.size());
     basefile.SetEndianness(Torch::Endianness::Big);
@@ -78,9 +112,12 @@ std::vector<uint8_t> CompTool::Decompress(std::vector<uint8_t> rom){
         count++;
     }
 
+    auto crcs = CompTool::CalculateCRCs(decompfile);
+
     decompfile.Seek(0x10, LUS::SeekOffsetType::Start);
-    decompfile.Write(0xA7D5F194); // CRC1
-    decompfile.Write(0xFE3DF761); // CRC2
+
+    decompfile.Write(crcs.first); // CRC1
+    decompfile.Write(crcs.second); // CRC2
 
     auto result = decompfile.ToVector();
     return { (uint8_t*) result.data(), (uint8_t*) result.data() + result.size() };
diff --git a/src/preprocess/CompTool.h b/src/preprocess/CompTool.h
index 15b7db5..73052bb 100644
--- a/src/preprocess/CompTool.h
+++ b/src/preprocess/CompTool.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "lib/binarytools/BinaryWriter.h"
 #include <cstdint>
 #include <string>
 #include <vector>
@@ -15,4 +16,6 @@ public:
     static std::vector<uint8_t> Decompress(std::vector<uint8_t> rom);
 private:
     static uint32_t FindFileTable(std::vector<uint8_t>& rom);
+    static std::pair<uint32_t, uint32_t> CalculateCRCs(LUS::BinaryWriter& decompFile);
+    static inline const uint32_t sCrcSeed = 0xF8CA4DDC;
 };
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