Adjusting dts will cause a rebuild of whole kernel as the buildroot
considers this a part of kernel source. It's a royal PITA when trying to
prepare support for new device, since this takes a lot of time on slower
systems. As it stands, buildroot itself, with own rule, also compiles
dtbs and the results are $(KDIR)/image-$(DEVICE_DTS).dtb. With setting
DEVICE_DTS_DIR to directory holding the device dts (similarly to some
other targets), buildroot doesn't consider changed dts as part of kernel
source and rebuilds only dtb. This really speeds up development. And
since the kernel built dts are no longer used, drop the paches adding
dtses to its build.
Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Reviewed-by: Robert Marko <robimarko@gmail.com>
Google WiFi (codename: Gale) is an IPQ4019-based AP, with 2 Ethernet
ports, 2x2 2.4+5GHz WiFi, 512 MB RAM, 4 GB eMMC, and a USB type C port.
In its stock configuration, it runs a Chromium OS-based system, but you
wouldn't know it, since you can only manage it via a "cloud" +
mobile-app system.
The "v2" label is coded into the bootloader, which prefers the
"google,gale-v2" compatible string. I believe "v1" must have been
pre-release hardware.
Note: this is *not* the Google Nest WiFi, released in 2019.
I include "factory.bin" support, where we generate a GPT-based disk
image with 2 partitions -- a kernel partition (using the custom "Chrome
OS kernel" GUID type) and a root filesystem partition. See below for
flashing instructions.
Sysupgrade is supported via recent emmc_do_upgrade() helper.
This is a subtarget because it enables different features
(FEATURES=boot-part rootfs-part) whose configurations don't make sense
in the "generic" target, and because it builds in a few USB drivers,
which are necessary for installation (installation is performed by
booting from USB storage, and so these drivers cannot be built as
modules, since we need to load modules from USB storage).
Flashing instructions
=====================
Documented here:
https://openwrt.org/inbox/toh/google/google_wifi
Note this requires booting from USB storage.
Features
========
I've tested:
* Ethernet, both WAN and LAN ports
* eMMC
* USB-C (hub, power-delivery, peripherals)
* LED0 (R/G/B)
* WiFi (limited testing)
* SPI flash
* Serial console: once in developer mode, console can be accessed via
the USB-C port with SuzyQable, or other similar "Closed Case
Debugging" tools:
https://chromium.googlesource.com/chromiumos/third_party/hdctools/+/master/docs/ccd.md#suzyq-suzyqable
* Sysupgrade
Not tested:
* TPM
Known not working:
* Reboot: this requires some additional TrustZone / SCM
configuration to disable Qualcomm's SDI. I have a proposal upstream,
and based on IRC chats, this might be acceptable with additional DT
logic:
[RFC PATCH] firmware: qcom_scm: disable SDI at boot
https://lore.kernel.org/linux-arm-msm/20200721080054.2803881-1-computersforpeace@gmail.com/
* SMP: enabling secondary CPUs doesn't currently work using the stock
bootloader, as the qcom_scm driver assumes newer features than this
TrustZone firmware has. I posted notes here:
[RFC] qcom_scm: IPQ4019 firmware does not support atomic API?
https://lore.kernel.org/linux-arm-msm/20200913201608.GA3162100@bDebian/
* There's a single external button, and a few useful internal GPIO
switches. I haven't hooked them up.
The first two are fixed with subsequent commits.
Additional notes
================
Much of the DTS is pulled from the Chrome OS kernel 3.18 branch, which
the manufacturer image uses.
Note: the manufacturer bootloader knows how to patch in calibration data
via the wifi{0,1} aliases in the DTB, so while these properties aren't
present in the DTS, they are available at runtime:
# ls -l
/sys/firmware/devicetree/base/soc/wifi@a*/qcom,ath10k-pre-calibration-data
-r--r--r-- 1 root root 12064 Jul 15 19:11 /sys/firmware/devicetree/base/soc/wifi@a000000/qcom,ath10k-pre-calibration-data
-r--r--r-- 1 root root 12064 Jul 15 19:11 /sys/firmware/devicetree/base/soc/wifi@a800000/qcom,ath10k-pre-calibration-data
Ethernet MAC addresses are similarly patched in via the ethernet{0,1} aliases.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
(updated 901 - x1pro moved in the process)
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
See firmware-utils.git commits [1], which implemented the cros-vbutil
verified-boot payload-packing tool, and extended ptgen for the CrOS
kernel partition type. With these, it's now possible to package kernel +
rootfs to make disk images that can boot a Chrome OS-based system (e.g.,
Chromebooks, or even a few AP models).
Regarding PARTUUID= changes: Chromium bootloaders work well with a
partition number offset (i.e., relative to the kernel partition), so
we'll be using a slightly different root UUID line.
NB: I've made this support specific to ip40xx for now, because I only
plan to support an IPQ4019-based AP that uses a Chromium-based
bootloader, but this image format can be used for essentially any
Chromebook, as well as the Google OnHub, a prior Chromium-based AP using
an IPQ8064 chipset.
[1]
ptgen: add Chromium OS kernel partition support
https://git.openwrt.org/?p=project/firmware-utils.git;a=commit;h=6c95945b5de973026dc6f52eb088d0943efa96bb
cros-vbutil: add Chrome OS vboot kernel-signing utility
https://git.openwrt.org/?p=project/firmware-utils.git;a=commit;h=8e7274e02fdc6f2cb61b415d6e5b2e1c7e977aa1
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
