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/*
* UniqueId.cpp
*
* Created on: 4 Oct 2021
* Author: David
*/
#include "UniqueId.h"
// Append the unique ID in character form to an output buffer
void UniqueId::AppendCharsToBuffer(OutputBuffer *buf) const noexcept
{
AppendCharsTo([buf](char c)-> void { buf->cat(c);});
}
// Generate a MAC address from this unique ID. Caller should check IsValid() first.
void UniqueId::GenerateMacAddress(MacAddress& addr) const noexcept
{
// The unique ID is 128 bits long whereas the whole MAC address is only 48 bits, so we can't guarantee that each Duet will get a unique MAC address this way.
// There are 16 ID bytes not including the checksum. It appears that the last bytes are more likely to change, so they must be included.
memset(addr.bytes, 0, sizeof(addr.bytes));
addr.bytes[0] = 0xBE; // use a fixed first byte with the locally-administered bit set
const uint8_t * const idBytes = reinterpret_cast<const uint8_t *>(data);
for (size_t i = 0; i < 16; ++i)
{
addr.bytes[(i % 5) + 1] ^= idBytes[i];
}
}
// End
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