From 39c3f72c41fa08a65e93bbe1fd2f408099dd9db7 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Wed, 7 Aug 2019 18:35:28 -0500
Subject: [PATCH] [Kernel] Implement RtlComputeCrc32.

---
 src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc | 67 +++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc b/src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc
index 3b71a4dd5..526a262d5 100644
--- a/src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc
+++ b/src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc
@@ -549,6 +549,73 @@ dword_result_t RtlTimeFieldsToTime(pointer_t<X_TIME_FIELDS> time_fields_ptr,
 }
 DECLARE_XBOXKRNL_EXPORT1(RtlTimeFieldsToTime, kNone, kImplemented);
 
+static uint32_t crc32_table[256] = {
+    0x00000000u, 0x77073096u, 0xEE0E612Cu, 0x990951BAu, 0x076DC419u,
+    0x706AF48Fu, 0xE963A535u, 0x9E6495A3u, 0x0EDB8832u, 0x79DCB8A4u,
+    0xE0D5E91Eu, 0x97D2D988u, 0x09B64C2Bu, 0x7EB17CBDu, 0xE7B82D07u,
+    0x90BF1D91u, 0x1DB71064u, 0x6AB020F2u, 0xF3B97148u, 0x84BE41DEu,
+    0x1ADAD47Du, 0x6DDDE4EBu, 0xF4D4B551u, 0x83D385C7u, 0x136C9856u,
+    0x646BA8C0u, 0xFD62F97Au, 0x8A65C9ECu, 0x14015C4Fu, 0x63066CD9u,
+    0xFA0F3D63u, 0x8D080DF5u, 0x3B6E20C8u, 0x4C69105Eu, 0xD56041E4u,
+    0xA2677172u, 0x3C03E4D1u, 0x4B04D447u, 0xD20D85FDu, 0xA50AB56Bu,
+    0x35B5A8FAu, 0x42B2986Cu, 0xDBBBC9D6u, 0xACBCF940u, 0x32D86CE3u,
+    0x45DF5C75u, 0xDCD60DCFu, 0xABD13D59u, 0x26D930ACu, 0x51DE003Au,
+    0xC8D75180u, 0xBFD06116u, 0x21B4F4B5u, 0x56B3C423u, 0xCFBA9599u,
+    0xB8BDA50Fu, 0x2802B89Eu, 0x5F058808u, 0xC60CD9B2u, 0xB10BE924u,
+    0x2F6F7C87u, 0x58684C11u, 0xC1611DABu, 0xB6662D3Du, 0x76DC4190u,
+    0x01DB7106u, 0x98D220BCu, 0xEFD5102Au, 0x71B18589u, 0x06B6B51Fu,
+    0x9FBFE4A5u, 0xE8B8D433u, 0x7807C9A2u, 0x0F00F934u, 0x9609A88Eu,
+    0xE10E9818u, 0x7F6A0DBBu, 0x086D3D2Du, 0x91646C97u, 0xE6635C01u,
+    0x6B6B51F4u, 0x1C6C6162u, 0x856530D8u, 0xF262004Eu, 0x6C0695EDu,
+    0x1B01A57Bu, 0x8208F4C1u, 0xF50FC457u, 0x65B0D9C6u, 0x12B7E950u,
+    0x8BBEB8EAu, 0xFCB9887Cu, 0x62DD1DDFu, 0x15DA2D49u, 0x8CD37CF3u,
+    0xFBD44C65u, 0x4DB26158u, 0x3AB551CEu, 0xA3BC0074u, 0xD4BB30E2u,
+    0x4ADFA541u, 0x3DD895D7u, 0xA4D1C46Du, 0xD3D6F4FBu, 0x4369E96Au,
+    0x346ED9FCu, 0xAD678846u, 0xDA60B8D0u, 0x44042D73u, 0x33031DE5u,
+    0xAA0A4C5Fu, 0xDD0D7CC9u, 0x5005713Cu, 0x270241AAu, 0xBE0B1010u,
+    0xC90C2086u, 0x5768B525u, 0x206F85B3u, 0xB966D409u, 0xCE61E49Fu,
+    0x5EDEF90Eu, 0x29D9C998u, 0xB0D09822u, 0xC7D7A8B4u, 0x59B33D17u,
+    0x2EB40D81u, 0xB7BD5C3Bu, 0xC0BA6CADu, 0xEDB88320u, 0x9ABFB3B6u,
+    0x03B6E20Cu, 0x74B1D29Au, 0xEAD54739u, 0x9DD277AFu, 0x04DB2615u,
+    0x73DC1683u, 0xE3630B12u, 0x94643B84u, 0x0D6D6A3Eu, 0x7A6A5AA8u,
+    0xE40ECF0Bu, 0x9309FF9Du, 0x0A00AE27u, 0x7D079EB1u, 0xF00F9344u,
+    0x8708A3D2u, 0x1E01F268u, 0x6906C2FEu, 0xF762575Du, 0x806567CBu,
+    0x196C3671u, 0x6E6B06E7u, 0xFED41B76u, 0x89D32BE0u, 0x10DA7A5Au,
+    0x67DD4ACCu, 0xF9B9DF6Fu, 0x8EBEEFF9u, 0x17B7BE43u, 0x60B08ED5u,
+    0xD6D6A3E8u, 0xA1D1937Eu, 0x38D8C2C4u, 0x4FDFF252u, 0xD1BB67F1u,
+    0xA6BC5767u, 0x3FB506DDu, 0x48B2364Bu, 0xD80D2BDAu, 0xAF0A1B4Cu,
+    0x36034AF6u, 0x41047A60u, 0xDF60EFC3u, 0xA867DF55u, 0x316E8EEFu,
+    0x4669BE79u, 0xCB61B38Cu, 0xBC66831Au, 0x256FD2A0u, 0x5268E236u,
+    0xCC0C7795u, 0xBB0B4703u, 0x220216B9u, 0x5505262Fu, 0xC5BA3BBEu,
+    0xB2BD0B28u, 0x2BB45A92u, 0x5CB36A04u, 0xC2D7FFA7u, 0xB5D0CF31u,
+    0x2CD99E8Bu, 0x5BDEAE1Du, 0x9B64C2B0u, 0xEC63F226u, 0x756AA39Cu,
+    0x026D930Au, 0x9C0906A9u, 0xEB0E363Fu, 0x72076785u, 0x05005713u,
+    0x95BF4A82u, 0xE2B87A14u, 0x7BB12BAEu, 0x0CB61B38u, 0x92D28E9Bu,
+    0xE5D5BE0Du, 0x7CDCEFB7u, 0x0BDBDF21u, 0x86D3D2D4u, 0xF1D4E242u,
+    0x68DDB3F8u, 0x1FDA836Eu, 0x81BE16CDu, 0xF6B9265Bu, 0x6FB077E1u,
+    0x18B74777u, 0x88085AE6u, 0xFF0F6A70u, 0x66063BCAu, 0x11010B5Cu,
+    0x8F659EFFu, 0xF862AE69u, 0x616BFFD3u, 0x166CCF45u, 0xA00AE278u,
+    0xD70DD2EEu, 0x4E048354u, 0x3903B3C2u, 0xA7672661u, 0xD06016F7u,
+    0x4969474Du, 0x3E6E77DBu, 0xAED16A4Au, 0xD9D65ADCu, 0x40DF0B66u,
+    0x37D83BF0u, 0xA9BCAE53u, 0xDEBB9EC5u, 0x47B2CF7Fu, 0x30B5FFE9u,
+    0xBDBDF21Cu, 0xCABAC28Au, 0x53B39330u, 0x24B4A3A6u, 0xBAD03605u,
+    0xCDD70693u, 0x54DE5729u, 0x23D967BFu, 0xB3667A2Eu, 0xC4614AB8u,
+    0x5D681B02u, 0x2A6F2B94u, 0xB40BBE37u, 0xC30C8EA1u, 0x5A05DF1Bu,
+    0x2D02EF8Du,
+};
+
+dword_result_t RtlComputeCrc32(dword_t seed, lpvoid_t buffer, dword_t length) {
+  if (!length) {
+    return seed.value();
+  }
+  uint32_t hash = ~seed;
+  for (uint32_t i = 0; i < length; ++i) {
+    hash = crc32_table[buffer[i] ^ (hash & 0xFF)] ^ (hash >> 8);
+  }
+  return ~hash;
+}
+DECLARE_XBOXKRNL_EXPORT1(RtlComputeCrc32, kNone, kImplemented);
+
 void RegisterRtlExports(xe::cpu::ExportResolver* export_resolver,
                         KernelState* kernel_state) {}