http://www.linuxquestions.org/questions/linux-from-scratch-13/acpi-errors-when-booting-927408/
ah christ almighty, they're talking about "updating the bios fixes the problem" *sigh*. 3.16, 4.7 and 4.8 are all fine - so wtf is 4.9 doing not being capable of running /init when all prior version can... https://forum.manjaro.org/t/acpi-error-on-boot-after-updating-to-4-9/12894/9 argh, wtf???? https://wiki.archlinux.org/index.php/DSDT !! :) wtf??? apparently you can fix ACPI DSDT errors by disassembling the acpi table, hand-ending the bastard thing and recompiling it. this is a $USD 2,600 laptop. i don't fink i will be doin that. i'll try the trick of setting acpi_os_name to see if it tricks the ACPI BIOS into going via a different codepath. l.
