Chrome OS uses quite a lot of kernel parameters. So here is the full line as i see it in dmesg after booting into Chrome OS.
cros_secure console= loglevel=7 init=/sbin/init cros_secure oops=panic panic=-1 root=/dev/dm-0 rootwait ro dm_verity.error_behavior=3 dm_verity.max_bios=-1 dm_verity.dev_wait=1 dm="1 vroot none ro 1,0 2506752 verity payload=PARTUUID=XXX/PARTNROFF=1 hashtree=PARTUUID=XXX/PARTNROFF=1 hashstart=2506752 alg=sha1 root_hexdigest=XXX salt=XXX" noinitrd vt.global_cursor_default=0 kern_guid=XXX add_efi_memmap boot=local noresume noswap i915.modeset=1 tpm_tis.force=1 tpm_tis.interrupts=0 nmi_watchdog=panic,lapic iTCO_vendor_support.vendorsupport=3 gpt
The lightbar on the Pixel can be controlled through EC. The tool for this is ectool
which is part of
the Chrome OS installation.
ectool lightbar seq stop
ectool lightbar seq run
ectool lightbar seq konami
ectool lightbar seq stop
ectool lightbar 4 00 ff 00
ectool lightbar 0 00 00 ff
ectool lightbar off
ectool lightbar on
ectool lightbar init
ectool lightbar seq run
To get all this on Linux we need the ectool
binary. The source code and
details is checked into Chromium OS repository.
There is also a Mainline Kernel patch available which exposes EC lightbar through sysfs. I might add this to my Kernel patches eventually. THis patch has been submitted to the upstream Kernel here. These patches require a modified ectool which seems to be available too.
git clone git://git.collabora.co.uk/git/user/javier/ec.git
cd ec
git checkout mainline-ioctl
make BOARD=link CROSS_COMPILE= HOST_CROSS_COMPILE= build/link/util/ectool
sudo ./build/link/util/ectool version
Once you have ectool built for Linux it can be used to get control on the fan.
sudo ./build/link/util/ectool fanduty 0
sudo ./build/link/util/ectool fanduty 100
sudo ./build/link/util/ectool autofanctrl on
http://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices/chromebook-pixel