1# X86 power control 2 3This repository contains an OpenBMC compliant implementation of power control 4for x86 servers. It relies on a number of features to do its job. It has 5several intentional design goals. 61. The BMC should maintain the Host state machine internally, and be able to 7 track state changes. 82. The implementation should either give the requested power control result, or 9 should log an error on the failure it detected. 103. The BMC should support all the common operations, hard power on/off/cycle, 11 soft power on/off/cycle. 12 13At this point in time, this daemon targets Lewisburg based, dual socket x86 14server platforms, such as S2600WFT. It is likely that other platforms will work 15as well. 16 17Because this relies on the hardware passthrough support in the AST2500 to 18function, it requires a few patches to work correctly. 19 20This patch adds support to UBOOT to keep the passthrough enabled 21https://github.com/Intel-BMC/openbmc/blob/intel/meta-openbmc-mods/meta-common/ 22recipes-bsp/u-boot/files/0005-enable-passthrough-in-uboot.patch 23 24The DTS file for your platform will need the following GPIO definitions 25RESET_BUTTON 26RESET_OUT 27POWER_BUTTON 28POWER_OUT 29 30On an aspeed, these are generally connected to E0, E1, E2, and E3 respecitvely. 31An example of this is available in the s2600WF config. 32 33This patch allows the passthrough to be reenabled to the default condition when 34the appropriate pin is released. This allows power control to take control 35when needed by a user power action, but leave the hardware in control a majority 36of the time, reducing the possibilty of bricking a system due to a failed BMC. 37 38https://github.com/Intel-BMC/openbmc/blob/intel/meta-openbmc-mods/meta-ast2500/recipes-kernel/linux/linux-aspeed/0002-Enable-pass-through-on-GPIOE1-and-GPIOE3-free.patch 39https://github.com/Intel-BMC/openbmc/blob/intel/meta-openbmc-mods/meta-ast2500/recipes-kernel/linux/linux-aspeed/0003-Enable-GPIOE0-and-GPIOE2-pass-through-by-default.patch 40https://github.com/Intel-BMC/openbmc/blob/intel/meta-openbmc-mods/meta-ast2500/recipes-kernel/linux/linux-aspeed/0006-Allow-monitoring-of-power-control-input-GPIOs.patch 41 42 43Caveats: 44This implementation does not currently implement the common targets that other 45implementations do. There were several attempts to, but all ended in timing 46issues and boot inconsistencies during stress operations. 47