Deviceinfo reference

From postmarketOS
Jump to navigation Jump to search

Most of the variables in deviceinfo have self-explanatory names and are used both when you are building postmarketOS (edit at .local/var/pmbootstrap/cache_git/pmaports/device/your_device_name/deviceinfo before flashing, and during runtime it is available at /etc/deviceinfo). if edited before flashing, be sure to rebuild the file with pmbootstrap install

All variables start with deviceinfo_ in the file - this is omitted here to save space.


Variable Description Possibles values
format_version Used to distinguish between different versions of this file. 0
name Device model e.g. Nokia N900
manufacturer Device manufacturer e.g. Nokia
codename Device codename e.g. nokia-n900
year Release year of the device e.g. 2012
chassis The computer case of your device (!1933) e.g. handset for phones, watch (all values)
keyboard The device has a hardware keyboard. true, false
dtb Name of the device tree blob file (only used on mainline kernels). See the option append_dtb on how this is used. e.g. allwinner/sun50i-a64-pine64-lts or qcom-msm8974-lge-nexus5-hammerhead
append_dtb Set to true if the dtb should be appended to the Linux kernel image, if set to false the dtb will be copied to the /boot partition instead. (pmaports!387) true, false
modules_initfs Kernel modules to include in the initramfs image. Modules ext4 and usb_f_rndis should not be included in this list, they are always added to the initramfs image if they were built as module (pmaports!673). Note: modules to be loaded after the initramfs can be specified like in a modules-load.conf (example).
external_storage Does the device have an sdcard or other external storage medium? true, false
flash_method Method used to flash the device (more info)
arch Device architecture, must be supported by Alpine Linux armhf, armv7, aarch64, x86, x86_64
dev_internal_storage Path to the internal storage (eMMC) (currently only used by the on-device installer). Only set this if you will use it. (pmaports!1820) e.g. /dev/vdb
dev_internal_storage_repartition Allow the internal storage to be repartitioned by postmarketOS in the on-device installer. This makes it possible to install from SD card to eMMC (pmaports!1820).

This is dangerous and should not be enabled for Android devices! For Android devices, we never change the partition table, because the bootloader expects the boot.img to be at a specific partition and changing the partition scheme would likely result in the original OS not being usable anymore.

true, false
dev_touchscreen Path to the touchscreen device (only necessary if not automatically detected, more info) e.g. /dev/input/event3
dev_touchscreen_calibration Touchscreen calibration values (only necessary for devices with resistive touchscreen, more info) e.g. 1.094563 -0.020949 -34.586121 0.009427 -1.148506 503.816956
keymaps Lists keymap options that are available for this device, this will be shown as options in the pmbootstrap init command, this will be passed to Alpine's setup-keymap command us/rx51_us ch/rx51_ch it/rx51_it
swap_size_recommended Set recommended swap file size for device. If unset, no swap file will be created for the device. Integer, in MB.
disable_dhcpd Do not set the static ip to the network interface and do not run the DHCP daemon on it. This makes sense for devices with an ethernet port, like the Raspberry Pi (#1580). true, false
no_framebuffer Do not wait up to 10 seconds until a framebuffer device shows up and do not try to configure it (pmaports!44). true, false
initfs_compression Command used to compress initramfs image (see pmaports!334, pmaports#237) default: 'gzip -1'
getty Configure a getty on boot. Creates an entry in /etc/inittab <port>;<baudrate>
e.g. ttyS0;115200
default: not set
mesa_driver The name of the mesa driver, which will be copied to initramfs to enable hardware acceleration of osk-sdl. Will be resolved to /usr/lib/xorg/modules/dri/${deviceinfo_mesa_driver} (pmaports!1625). When set, the device package must depend on mesa-egl. Read this guide to find the proper value. e.g. sun4i-drm, msm


These are used for flashing and booting the device, and most of them are fastboot specific. Here is a guide on how to get these values for a specific Android device (by extracting the boot.img)

Variable Description Possible values
flash_offset_kernel Kernel offset used for flashing
flash_offset_ramdisk Ramdisk offset used for flashing
flash_offset_second Used for flashing
flash_offset_tags Used for flashing
flash_offset_base Used for flashing default: 0x10000000
flash_pagesize Page size usually 2048
flash_sparse Set this to true if your device expects a sparse system image flashed
kernel_cmdline Kernel command line
bootimg_blobpack Create a flashable blob for the ASUS Transformers from boot.img using BlobTools true, sign, false
bootimg_mtk_mkimage Prepend a header required for MediaTek MT6589 phones (such as the Fairphone 1, more info) true, false
bootimg_qcdt Append dtb file to boot.img (more info) true, false
bootimg_dtb_second Place the dtb in the "second" area of the Android boot image. See pmaports!700 for details. true, false
bootimg_append_seandroidenforce Append SEANDROIDENFORCE file to boot.img See pmaports!1000 for details. true, false
bootimg_pxa Set this to true if the device is based on the Marvell PXA1088/1908 chipset, which has header layout differences. Makes mkinitfs generate the boot image with a different mkbootimg. pxa-mkbootimg should be added as a dependency to your device package. true, false
generate_bootimg Set this to true for fastboot device, so the mkinitfs command will generate a boot.img file after creating the initfs. Add mkbootimg as dependency to your device's APKBUILD! true, false
generate_legacy_uboot_initfs For the Nokia N900, we use a legacy version of the uboot bootloader right now. When setting this variable to true, the initramfs will generate an uboot legacy compatible initramfs file. Modern versions of uboot can load regular initramfs files. true, false
legacy_uboot_load_address Set a custom load address for the legacy uboot initfs (see pmaports!578, only makes sense in combination with generate_legacy_uboot_initfs). default: 80008000
flash_fastboot_partition_kernel Only relevant for fastboot flash methods, the partition where the kernel or boot.img will be stored (!1741). default: "boot"
flash_fastboot_partition_system Only relevant for fastboot flash methods, the partition where the system image will be stored (see also: partition-layout). default: "system"
flash_fastboot_partition_vbmeta For AVB devices: set vbmeta partition to be flashed with a custom vbmeta.img which has verity flag disabled (!1885). partition name, e.g. vbmeta
flash_fastboot_max_size Set this if the fastboot required by your device has an upper limit to the size of system images it will flash. Size, in MB
flash_heimdall_partition_kernel Only relevant for heimdall flash methods, the partition where the kernel or boot.img will be stored. default: "KERNEL"
flash_heimdall_partition_initfs Only relevant for the heimdall-isorec flash method, the partition where the initramfs will be stored. default: "RECOVERY"
flash_heimdall_partition_system Only relevant for heimdall flash methods, the partition where the system image will be stored (see also: partition-layout). default: "SYSTEM"
flash_heimdall_partition_vbmeta For AVB devices: set vbmeta partition to be flashed with a custom vbmeta.img which has verity flag disabled (!1936, !1885). partition name, e.g. VBMETA
boot_filesystem Sets the filesystem used for the /boot partition containing initramfs-extra default: "ext4", "fat16", "fat32"
root_filesystem Sets the filesystem used for the / partition (!2011) default: "ext4"
rootfs_image_sector_size Some devices made after 2016 with UFS storage use 4096 byte sectors and therefore need this option to boot. Read !1725 for details. default: 512
sd_embed_firmware A comma-separated list of binary:offset (where binary is under /usr/share) (!1739) e.g. firmware/librem5dev/u-boot.bin:33,firmware/librem5dev/m4.bin:2
sd_embed_firmware_step_size The number of bytes for each increment of the offset specified in the sd_embed_firmware default: 1024
partition_blacklist A comma-separated list of partitions that should not be flashed, because they brick the device. There are only very few devices where it is necessary (e.g. Ouya). !1759 e.g. boot,recovery
boot_part_start Number of sectors from the start of the drive to place the boot partition. Some devices may need this increased, if their bootloader takes up more space (like the Librem 5). (!1856) default: 2048
mkinitfs_postprocess A script that runs after generating the initramfs. It gets the path to the generated initramfs file as parameter. An example use case is applying a signature verification hack to a boot.img file for amazon-soho (pmaports!2056). e.g. /usr/share/postmarketos-mkinitfs/


Variable Description Possibles values
screen_width The width of the display 800, 720, 1440... anything really
screen_height The height of the display 1280, 2560... other
framebuffer_landscape Rotate framebuffer output by 270° (pmaports!530, pmaports!546) true, false (default)


Change how the target device shows up when connected with USB to a host PC. pmaports!706 added support for these variables in the mkinitfs script, when using the configfs network method.

Variable Description Default
usb_idVendor Vendor ID 0x18D1 ("Google Inc.")
usb_idProduct Product ID 0xD001 ("Nexus 4 (fastboot)")
usb_serialnumber Device's serial number string postmarketOS
usb_rndis_function Name of the rndis function, which may be different in some downstream kernels. The function is always located in /config/usb_gadget/g1/functions/ rndis.usb0

The correct IDs can be seen in init.*.usb.rc of Android/TWRP sources for that device (or directly in rootfs, boot into twrp and see) OR plug in device running stock Android/TWRP and watch dmesg for things like

[    3.939519] usb 1-2.4: New USB device found, idVendor=2717, idProduct=ff40, bcdDevice= 4.14
[    3.939521] usb 1-2.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    3.939521] usb 1-2.4: Product: MI 9
[    3.939522] usb 1-2.4: Manufacturer: Xiaomi

Obsolete options


  • weston_pixman_type: used to be a Weston specific workaround for the "red screen bug" (#54): we patched Weston to accept a --pixman-type argument to override the framebuffer mode that the kernel driver reports. However, this patch was quickly incompatible with future changes in Weston, and it is not as good as patching the kernel to report the right framebuffer mode, so it was removed (pmaports#136).
  • Various options from weston.ini used to be duplicated, but this was removed in #739. If you need to set weston specific options from your device (such as the output backend or the keymap), please add a weston.ini file to your pmaport (example).


  • nonfree: Components of the device, that only run with closed source firmware. This is now legacy due to nobody uses it. (pmaports#438)
  • dev_keyboard: Originally intended to point osk-sdl to the hardware keyboard, but was never used. (It should detect hardware keyboards automatically...)


  • flash_fastboot_vendor_id: fastboot used to have a -i option, but this was removed (#1830). Since we only had one device using this and nobody to verify if the option is really needed with this device, we decided to remove it. If you are interested in bringing it back, please create a new issue.

See also