From 1281a1fc97992b8561f500bf2d0f222149031d4b Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Tue, 23 Jun 2015 12:18:53 +0800 Subject: [PATCH] x86: Update README.x86 for SMP support Document U-Boot multi-processor support as well as configuration tables like SFI and MP tables for SMP OS kernel. Signed-off-by: Bin Meng Acked-by: Simon Glass --- doc/README.x86 | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/doc/README.x86 b/doc/README.x86 index c19f4a03ba..49d6e83046 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -258,6 +258,17 @@ Modern CPUs usually require a special bit stream called microcode [6] to be loaded on the processor after power up in order to function properly. U-Boot has already integrated these as hex dumps in the source tree. +SMP Support +----------- +On a multicore system, U-Boot is executed on the bootstrap processor (BSP). +Additional application processors (AP) can be brought up by U-Boot. In order to +have an SMP kernel to discover all of the available processors, U-Boot needs to +prepare configuration tables which contain the multi-CPUs information before +loading the OS kernel. Currently U-Boot supports generating two types of tables +for SMP, called Simple Firmware Interface (SFI) [7] and Multi-Processor (MP) [8] +tables. The writing of these two tables are controlled by two Kconfig options +GENERATE_SFI_TABLE and GENERATE_MP_TABLE. + Driver Model ------------ x86 has been converted to use driver model for serial and GPIO. @@ -362,3 +373,5 @@ References [4] http://www.intel.com/content/www/us/en/embedded/design-tools/evaluation-platforms/atom-e660-eg20t-development-kit.html [5] http://www.intel.com/fsp [6] http://en.wikipedia.org/wiki/Microcode +[7] http://simplefirmware.org +[8] http://www.intel.com/design/archives/processors/pro/docs/242016.htm -- 2.39.5