From 52f6d727139038469aef450502527a24838f1587 Mon Sep 17 00:00:00 2001 From: Tim Crawford Date: Thu, 7 Sep 2023 06:58:47 -0600 Subject: [PATCH] docs: Add note about checking CSME state I had forgotten that CSME reporting an error was normal when disabled. Document what is should report when enabled/disabled. Signed-off-by: Tim Crawford --- docs/intel-me.md | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/docs/intel-me.md b/docs/intel-me.md index 4842350..eacab93 100644 --- a/docs/intel-me.md +++ b/docs/intel-me.md @@ -27,6 +27,34 @@ A restart is required for the change to take effect. On the boot after changing the value, the system will perform a global reset (power off again) to complete the change and ensure the IME is operating in a valid state. +### Checking the state + +coreboot will log some IME data to cbmem during startup. This can be used to +check if it is in the correct state. + +``` +make -C coreboot/util/cbmem +sudo ./coreboot/util/cbmem/cbmem -c +``` + +When disabled it will report: + +``` +ME: Current Working State : 4 +ME: Current Operation State : 1 +ME: Current Operation Mode : 3 +ME: Error Code : 2 +``` + +When enabled it will report: + +``` +ME: Current Working State : 5 +ME: Current Operation State : 1 +ME: Current Operation Mode : 0 +ME: Error Code : 0 +``` + ## Tiger Lake-U Models using TGL-U processors default to having the IME enabled. TGL-U removes