-----Original Message----- From: coreboot-bounces+scott=notabs.org@coreboot.org [mailto:coreboot-bounces+scott=notabs.org@coreboot.org] On Behalf Of Xavi Drudis Ferran Sent: Monday, February 21, 2011 07:48 AM To: Stefan Reinauer; coreboot@coreboot.org Subject: Re: [coreboot] [PATCH] disabling microcode update
]Rationale for disabling microcode update: ] ]Ivaylo and I have had issues when updating microcode in FAM10 ] ]We dont' have source for it (if it exists at all)
This really isn't relevant, but microcode patch source code certainly exists, as does source code for the main microcode that the patch modifies. A microcode assembler converts the source code into binary form.
Think about what it would take for public microcode patch source code to be useful. First, the processor vendor would have to publish the thousands of lines of source code for the microcode that will be patched. Next, the microcode assembler and related tools would have to be published. At that point, a lot of training is needed to even understand the microcode. Microcode is not written in any standard programming language. The language is completely different for different processor vendors, and even for different processor models in some cases. Anyway, assume that somehow a non-employee became a microcode expert for a particular processor model. Why would the patch need to be modified? The patch corrects a processor erratum. To modify microcode in a way that works around a processor erratum usually requires details of the processor design that are not published.
When a processor is purchased, its source code is not provided. The microcode patch is a modification of the processor design, so it is not surprising the source code is not supplied.
Thanks, Scott
Next, the processor vendor will have to publish the source code to the microprocessor itself. The microprocessor source code is needed