add ota algorithm for device

1. effective "Differential Upgrade" patch algorithm with high compression rate
2. effective recovery algorithm support recovery firmware in blocks which has low memory consumption and wear-leveling strategies, especially suitable for embeded devices with low RAM.
3. add sample ota bootloader project, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_bootloader_recovery
4. add sample application project for download firmware through http, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_http
5. add sample application project for download firmware through qcloud explorer console, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_qcloud_iot_explorer
6. an OTA markdown document is pending

components/ota/common/lzma/3rdparty/7zCrc.c

@@ -0,0 +1,128 @@
+/* 7zCrc.c -- CRC32 init
+2017-06-06 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "7zCrc.h"
+#include "CpuArch.h"
+
+#define kCrcPoly 0xEDB88320
+
+#ifdef MY_CPU_LE
+  #define CRC_NUM_TABLES 8
+#else
+  #define CRC_NUM_TABLES 9
+
+  #define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24))
+
+  UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table);
+  UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table);
+#endif
+
+#ifndef MY_CPU_BE
+  UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table);
+  UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table);
+#endif
+
+typedef UInt32 (MY_FAST_CALL *CRC_FUNC)(UInt32 v, const void *data, size_t size, const UInt32 *table);
+
+CRC_FUNC g_CrcUpdateT4;
+CRC_FUNC g_CrcUpdateT8;
+CRC_FUNC g_CrcUpdate;
+
+UInt32 g_CrcTable[256 * CRC_NUM_TABLES];
+
+UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)
+{
+  return g_CrcUpdate(v, data, size, g_CrcTable);
+}
+
+UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)
+{
+  return g_CrcUpdate(CRC_INIT_VAL, data, size, g_CrcTable) ^ CRC_INIT_VAL;
+}
+
+#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
+
+UInt32 MY_FAST_CALL CrcUpdateT1(UInt32 v, const void *data, size_t size, const UInt32 *table)
+{
+  const Byte *p = (const Byte *)data;
+  const Byte *pEnd = p + size;
+  for (; p != pEnd; p++)
+    v = CRC_UPDATE_BYTE_2(v, *p);
+  return v;
+}
+
+void MY_FAST_CALL CrcGenerateTable()
+{
+  UInt32 i;
+  for (i = 0; i < 256; i++)
+  {
+    UInt32 r = i;
+    unsigned j;
+    for (j = 0; j < 8; j++)
+      r = (r >> 1) ^ (kCrcPoly & ((UInt32)0 - (r & 1)));
+    g_CrcTable[i] = r;
+  }
+  for (i = 256; i < 256 * CRC_NUM_TABLES; i++)
+  {
+    UInt32 r = g_CrcTable[(size_t)i - 256];
+    g_CrcTable[i] = g_CrcTable[r & 0xFF] ^ (r >> 8);
+  }
+
+  #if CRC_NUM_TABLES < 4
+  
+  g_CrcUpdate = CrcUpdateT1;
+  
+  #else
+ 
+  #ifdef MY_CPU_LE
+
+    g_CrcUpdateT4 = CrcUpdateT4;
+    g_CrcUpdate = CrcUpdateT4;
+
+    #if CRC_NUM_TABLES >= 8
+      g_CrcUpdateT8 = CrcUpdateT8;
+  
+      #ifdef MY_CPU_X86_OR_AMD64
+      if (!CPU_Is_InOrder())
+      #endif
+        g_CrcUpdate = CrcUpdateT8;
+    #endif
+
+  #else
+  {
+    #ifndef MY_CPU_BE
+    UInt32 k = 0x01020304;
+    const Byte *p = (const Byte *)&k;
+    if (p[0] == 4 && p[1] == 3)
+    {
+      g_CrcUpdateT4 = CrcUpdateT4;
+      g_CrcUpdate = CrcUpdateT4;
+      #if CRC_NUM_TABLES >= 8
+      g_CrcUpdateT8 = CrcUpdateT8;
+      g_CrcUpdate = CrcUpdateT8;
+      #endif
+    }
+    else if (p[0] != 1 || p[1] != 2)
+      g_CrcUpdate = CrcUpdateT1;
+    else
+    #endif
+    {
+      for (i = 256 * CRC_NUM_TABLES - 1; i >= 256; i--)
+      {
+        UInt32 x = g_CrcTable[(size_t)i - 256];
+        g_CrcTable[i] = CRC_UINT32_SWAP(x);
+      }
+      g_CrcUpdateT4 = CrcUpdateT1_BeT4;
+      g_CrcUpdate = CrcUpdateT1_BeT4;
+      #if CRC_NUM_TABLES >= 8
+      g_CrcUpdateT8 = CrcUpdateT1_BeT8;
+      g_CrcUpdate = CrcUpdateT1_BeT8;
+      #endif
+    }
+  }
+  #endif
+
+  #endif
+}