maggu2810

Asus Grouper (Google Nexus 7 2012)

postmarketOS related information

Author: Markus Rathgeb

General Notes

first setup u-boot
after u-boot is installed, install postmarketOS

postmarketOS Wiki: Asus Grouper (Archive)

Ensure correct device is used:

adb shell

grep androidboot.baseband=unknown /proc/cmdline && echo grouper || echo tilapia

find /sys/devices/ | grep -c max776 && echo You have E1565

find /sys/devices/ | grep -c tps6591 && echo You have PM269

Example

~ # grep androidboot.baseband=unknown /proc/cmdline && echo grouper || echo tilapia
tegra_wdt.heartbeat=30 tegraid=30.1.3.0.0 mem=1022M@2048M android.commchip=0 vmalloc=512M androidboot.serialno=015d456d85381609 video=tegrafb no_console_suspend=1 console=none debug_uartport=hsport usbcore.old_scheme_first=1 lp0_vec=8192@0xbddf9000 tegra_fbmem=8195200@0xabe01000 core_edp_mv=0 audio_codec=rt5640 board_info=f41:a00:1:44:2 tegraboot=sdmmc gpt gpt_sector=30785535 androidboot.bootloader=4.23 androidboot.baseband=unknown
grouper

~ # find /sys/devices/ | grep -c max776 && echo You have E1565
451
You have E1565

~ # find /sys/devices/ | grep -c tps6591 && echo You have PM269
0

u-boot

perform a backup first
- Guide: Tegra3 Guide: nvflash NEXUS 7 (and Transformer Jellybeans) (Archive)
- The links to the downloads are not working at the time of writing, here you can find them: https://github.com/AndroidRoot/androidroot.github.io/tree/master/download
- To use nvflash from nvflash-tools-linux you need support for 32 bit ELF files (for Fedora 40: dnf install glibc32 libstdc++.i686)
- wheelie source code can be found here, I compiled und used the current (at time of writing) master: https://github.com/AndroidRoot/wheelie
compile u-boot for asus grouper
- Guide: U-Boot for the ASUS/Google Nexus 7 (2012) (Archive)
- Toolchain: Arm GNU Toolchain Downloads (I used “x86_64 Linux hosted cross toolchains”, “AArch32 bare-metal target (arm-none-eabi)”, “arm-gnu-toolchain-13.2.rel1-x86_64-arm-none-eabi.tar.xz”)

dnf install swig

export PATH=/home/maggu2810/bin/pkgs/arm-gnu-toolchain/arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi/bin:"${PATH}"
export CROSS_COMPILE=arm-none-eabi-
make grouper_common_defconfig grouper_E1565.config
make

dump SBK
- Dump platform key (SBK) (Archive)
- If something went wrong power off the device and enter APX mode again. IIRC you can do some commands only initial on APX mode.

git clone --recursive https://github.com/tofurky/tegra30_debrick.git
cd tegra30_debrick
(cd fusee-launcher; make)

python -m venv venv
. venv/bin/activate
pip install pyusb

./fusee-launcher/fusee-launcher.py --tty ./fusee-launcher/dump-sbk-via-usb.bin

u-boot “repart-block.bin”
- Info:
  - “With nv3p, repart-block.bin is used. It contains BCT and a bootloader in encrypted state in form, which can just be written RAW at the start of eMMC.”
  - “Flashing repart-block.bin eliminates vendor restrictions on eMMC and allows the user to use/partition it in any way the user desires.”
- Build
  - Guide: U-Boot for the ASUS/Google Nexus 7 (2012) (Archive)
  - See:
    - “Process U-Boot”, “Processing for the NV3P protocol”
- Flash
  - Guide: U-Boot for the ASUS/Google Nexus 7 (2012) (Archive)
  - See:
    - “Flashing U-Boot into the eMMC”, “Flashing with the NV3P protocol”
u-boot usage
- Boot
  - To boot Linux, U-Boot will look for an extlinux.conf on eMMC.
  - Additionally, if the Volume Down button is pressed while booting, the device will enter bootmenu.
  - Bootmenu contains entries
    - to mount eMMC as mass storage
    - fastboot
    - reboot
    - reboot RCM
    - poweroff
    - enter U-Boot console
    - update bootloader
- Self Upgrading
  - Place your u-boot-dtb-tegra.bin on the first partition of the eMMC (using ability of u-boot to mount it). Enter bootmenu, choose update bootloader option with Power button and U-Boot should update itself. Once the process is completed, U-Boot will ask to press any button to reboot.

postmarketOS

build

“asus - grouper” moved to “nvidia - tegra-armv7”
- See: MR #4606: Nvidia Tegra ARMv7 switch to common packages
use SXMO for X11
- Issues: Phosh on Asus Nexus 7 2012 / grouper

install

Pre-requirement: u-boot

Enter the u-boot bootmenu
mount internal storage as usb mass storage device
connect tablet to linux PC
a new mass storage device should appear

dd if=/home/maggu2810/.local/var/pmbootstrap/chroot_native/home/pmos/rootfs/nvidia-tegra-armv7.img of=/dev/sdc bs=1M

customize

rootfs size

after system is booted ssh into the system, edit /boot/extlinux/extlinux.conf
add PMOS_FORCE_PARTITION_RESIZE kernel parameter to force resizing toofs partition
reboot
check df -h
remove parameter again

SXMO deviceprofile

sudo apk add libgpiod
sudo gpuinfo

(

DEVNAME="$(tr '\0' '\n' < /proc/device-tree/compatible | head -n1)"

DPNAME="sxmo_deviceprofile_${DEVNAME}.sh"

DPPATH="/usr/bin/${DPNAME}"

sudo rm -rf "${DPPATH}"

echo '#!/bin/sh
export SXMO_POWER_BUTTON="0:168"
export SXMO_VOLUME_BUTTONS="0:130 0:131"
#export SXMO_TOUCHSCREEN_ID="6"' | sudo tee "${DPPATH}" > /dev/null

sudo chmod 0755 "${DPPATH}"
sudo chown 0:0 "${DPPATH}"

)