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273f4000f0
* add new WiFimodes: WIFI_SHUTDOWN & WIFI_RESUME with example * restore WiFi.onWiFiModeChange()
43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
/*
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crc32.cpp
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Copyright (c) 2015 Ivan Grokhotkov. All rights reserved.
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This file is part of the esp8266 core for Arduino environment.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "coredecls.h"
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// moved from core_esp8266_eboot_command.cpp
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uint32_t crc32 (const void* data, size_t length, uint32_t crc /*= 0xffffffff*/)
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{
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const uint8_t* ldata = (const uint8_t*)data;
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while (length--)
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{
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uint8_t c = *ldata++;
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for (uint32_t i = 0x80; i > 0; i >>= 1)
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{
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bool bit = crc & 0x80000000;
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if (c & i)
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bit = !bit;
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crc <<= 1;
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if (bit)
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crc ^= 0x04c11db7;
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}
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}
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return crc;
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}
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