Arch Linux on Nexus 7 Flo Native

Here are my instructions on getting Arch Linux ARM natively booting on the Nexus 7 Flo. Ideally this would be booting from a usb stick or a dedicated partition on the mmc but this is working for me now.

BUGS!!!

There is no frambuffer console :( If you cannot get it booting you will need to reboot into recovery and check /proc/last_kmsg for the errors. Or try and build the UART cable (which I failed at)

There is only xf86-video-fbdev working and no DRM or anything fancy

The Software Refresher in the kernel does not work. You will need to run my refresher app or fix the kernel :)

The new xa code from x86-video-freedreno-git does not work. gpuaddr in kgsl_bo_gpuaddr comes back a 0

Quick Guide

1: I roughly followed the instructions form https://github.com/borh/nexus-7-2013-arch-scripts to get a working chroot first.

2: Edit the init script to point to your arch.img or partition

3: Edit and Run makebootimage.sh

4: fastboot boot newboot

5: ???

6: Profit

To get WiFi Working

A normal Nexus 7 Flo boot will call /system/bin/conn_init which does a whole lot of verifying your mac address and then writes out a config with the mac address in it. Very annoying. To get around this you need a copy of the wifi configs and manually enable the wifi driver since it does not start on boot. The firmware.service is only needed since I do not load the firmware in the initramfs (which I am haven't done yet)

1: Copy /system/vendor/firmware [android] to /usr/lib/firmware [arch] 2: rm /usr/lib/firmware/wlan/prima/{WCNSS_qcom_cfg.ini,WCNSS_qcom_wlan_nv.bin} <-- these are simlinks 3: cp /data/misc/wifi/{WCNSS_qcom_cfg.ini,WCNSS_qcom_wlan_nv.bin} /usr/lib/firmware/wlan/prima/ <-- these are the files which conn_init writes your mac address to

4: Copy firmware.service to /etc/systemd/system/ 5: ln -s /etc/systemd/system/firmware.service /etc/systemd/system/multi-user.target.wants/firmware.service

6: Create a wpa_supplicant-nl80211@wlan0.service with your wpa_supplicant.conf details 7: ln -s /etc/systemd/system/dhcpcd.service /etc/systemd/system/multi-user.target.wants/dhcpcd.service 8: ln -s /etc/systemd/system/sshd.service /etc/systemd/system/multi-user.target.wants/sshd.service

Note: Disable the wpa_supplicant hook in /etc/dhcpcd.conf

To get X working

Since there is no framebuffer console you cannot start X manually (unless you are able to get ssh working, see above) Auto login is your friend.

Be sure to install a window manager or something first and then follow https://wiki.archlinux.org/index.php/Automatic_login_to_virtual_console and https://wiki.archlinux.org/index.php/Start_X_at_Login

Your .xinitrc should contain something like ~/refresher & exec awesome

Refreshing (refresher.c)

Since the MSMFB_SW_REFRESHER does not seem to be working i wrote this instead. Just compile and put in you ~/ or whereever so xinit can run it.

Kernel stuff

You can use the kernel from here https://github.com/crondog/kernel_msm

To get Touchscreen working

Apply 0001-make-ektf3k-driver-report-non-MT-events-too.patch

Kernel configs

I used the following additional configs to get this working. Some might not be necessary but it helps with debugging

CONFIG_FB_MSM_DEFAULT_DEPTH_BGRA8888 (with RGBA patch from robclark) CONFIG_FHANDLE=y CONFIG_DEVTMPFS=y CONFIG_UTS_NS=y CONFIG_IPC_NS=y CONFIG_USER_NS=y CONFIG_PID_NS=y CONFIG_NET_NS=y CONFIG_DEVPTS_MULTIPLE_INSTANCES=y CONFIG_FANOTIFY=y CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_SPINLOCK=y CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_ATOMIC_SLEEP=y CONFIG_STACKTRACE=y CONFIG_DEBUG_BUGVERBOSE=y CONFIG_SECURITY_SELINUX_BOOTPARAM=y

Build initramfs

1: Edit makebootimage.sh with paths 2: cd systemd-initramfs; find . | cpio -o -H newc | gzip > ../minimal.initramfs 3: ./makebootimage.sh

Whats Working

Wifi fb0 Audio -- Need to setup Pulse Audio as systemwide. Not sure why it does not work as a normal user You will also need the alsaucm files from libasound2-data_1.0.27.2-1ubuntu6_all.deb Bluetooth - We now have bluez5 support :) Only tested with a Wedge keyboard

Not tested

NFC