Blame SOURCES/06-55-04_disclaimer

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Microcode revisions 0x2000065 and higher for Intel Skylake-X/W (family 6,
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model 85, stepping 4; CPUID 0x50654) are disabled as they may cause system
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hangs on reboot and the previous revision 0x2000064 is used instead.
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Please refer to /usr/share/doc/microcode_ctl/caveats/06-55-04_readme
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and /usr/share/doc/microcode_ctl/README.caveats for details.