Lenovo ThinkPad: Pressing power button in GRUB does not turn off system
On the Lenovo T60 (Type 2007 with dedicated/external ATI/AMD graphics card), using the vendor firmware, pressing the power button for one second in GRUB 2.04-5 (Debian Sid/unstable), the system turns off, and beeps once (after two seconds). GRUB with
set debug=all does not show anything (verified with serial console). So, it looks like this is done in SMM.
To match the vendor firmware, this should be also possible when using coreboot based firmware.