For an old CPU, finding all the valid instructions wasn’t very hard. You simply tried them all. Sure, really old CPUs might make it hard to tell what the instruction did, but once CPUs got illegal ...

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Video gamers know about cheat codes, but assembly language programmers are often in search of undocumented instructions. One way to find them is to map out all of a CPU’s opcodes and where there are ...

In a nutshell: Google researchers recently disclosed a stealthy security flaw dubbed "EntrySign" that allowed malicious code execution through unsigned microcode patches on AMD processors from Zen 1 ...

On January 8th Intel released new Linux Processor microcode data files that can be used to mitigate the Spectre and and Meltdown vulnerabilities in Intel CPUs. Using microcode files, an operating ...

My understanding was that a CPU microcode update is stored in non-volatile memory on the motherboard and is loaded by the BIOS or UEFI into volatile memory on the CPU during boot. And because the ...

Last month, a team of Google security researchers released a tool that can modify microcode of AMD's processors based on the Zen microarchitecture, the Zentool. While this is a security vulnerability, ...

In context: Microcode is machine instruction sets that load from the BIOS. It acts much like firmware for the PC's processor. According to MSI Marketing Director Eric van Beurden, AMD will be ...