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Xiaomi Redmi Note 7 (xiaomi-lavender)

Xiaomi Redmi Note 7
Redmi Note 7
Redmi Note 7
Manufacturer Xiaomi
Name Redmi Note 7
Codename xiaomi-lavender
Released 2019
Category testing
Original software Android 9, MIUI 10
postmarketOS kernel 4.4.153
Hardware
Chipset Qualcomm SDM660 Snapdragon 660
CPU 8-core (4x 2.2 GHz Kryo 260 & 4x 1.8 GHz Kryo 260)
GPU Adreno 512
Display 1080 x 2340
Storage 32/64/128 GB
Memory 3/4/6 GB
Architecture aarch64
Unixbench Whet/Dhry score -
Features
USB Networking
Works
Flashing
Works
Touchscreen
Works
Display
Works
WiFi
Broken
Xwayland
Works
FDE
Mainline
Partial
Battery
Works
3D Acceleration
Accelerometer
Audio
Bluetooth
Camera
GPS
Mobile data
SMS
Calls
USB OTG
Works



Contents

Contributors

Maintainer(s)

Users owning this device


How to enter flash mode

Bootloader Unlocking

Like other Xiaomi devices, the user will have to acquire the bootloader unlock key: https://en.miui.com/unlock

The device will not unlock if the device isn't 7 days old (from the time when your device connects to internet and powered on, and linked with Mi Account)

Recovery mode

  • Turn the device off (or restart also works)
  • Hold Volume Up and Power button
  • Once you feel vibration and phone turns on, release Power button
  • Keep holding Volume Up until you get to recovery.

Flashing (Download, Fastboot) mode

  • Same as recovery, but this time hold the Volume Down and Power keys.

Fastboot boot

In theory pmbootstrap flasher boot allows to directly boot kernel through USB without flashing it, but does not currently work. Bootloader does not like something about kernel compression:

Bootloader UART logs during "pmbootstrap flasher boot":

 Handling Cmd: boot
Booting Into Mission Mode
avb_slot_verify.c:432: DEBUG: Loading vbmeta struct from partition 'vbmeta'.
Partition found: vbmeta
avb_slot_verify.c:627: ERROR: vbmeta: Public key used to sign data rejected.
avb_slot_verify.c:704: DEBUG: vbmeta: VERIFICATION_DISABLED bit is set.
avb_slot_verify.c:317: DEBUG: dtbo: Loading entire partition.
Partition found: dtbo
State: Unlocked, AvbSlotVerify returned ERROR_PUBLIC_KEY_REJECTED, continue boot
VB2: Authenticate complete! boot state is: orange
VB2: boot state: orange(1)
Display menu is not enabled!
Device is unlocked, Skipping boot verification
VB2: BootState = 1
ReadKeyInternal: gEfiSimpleTextInputExProtocolGuid handles = 3
ReadKeyInternal: Read KEY = 0x0
 bootstate = 4
Cannot find GraphicsHandles.
ImageWidth=1080,ImageHeight=1920,LogoPosX=0,LogoPosY=0
Avoid flicking for 2160x1080 images 
Cannot find GraphicsHandles.
Render Splash  [3360687]
VB2: RenderSplashScreen end , BootState = 4 
No Ffbm cookie found, ignore: Not Found
Memory Base Address: 0x40000000
Decompressing kernel image start: 3360690 ms
Error in decompression: Something went wrong while decompression
Decompressing kernel image failed!!!

But it was reported to work for some people. Try it, might work for you

Installation

  • Install pmbootstrap first on your PC
  • make sure you have TWRP installed on the phone, it will help you to make backups:
  • backup boot, dtbo and system partitions first from TWRP, something like this, for example, to SD card:
adb shell
dd if=/dev/block/bootdevice/by-name/boot of=/external_sd/backups/orig_boot.img
dd if=/dev/block/bootdevice/by-name/dtbo of=/external_sd/backups/orig_dtbo.img
dd if=/dev/block/bootdevice/by-name/system of=/external_sd/backups/orig_system.img
  • zap & reinit pmbootstrap (pmbootstrap -y zapĀ ; pmbootstrap init), choose xiaomi-lavender as a device
  • proceed with installation as usual: reboot device to fastboot mode, then:
pmbootstrap install
pmbootstrap flasher flash_kernel
pmbootstrap flasher flash_rootfs
pmbootstrap flasher flash_vbmeta

For mainline kernel only (where nothing works except UART):

fastboot erase dtbo

And then

fastboot reboot

Tested UIs

  • weston
  • xfce4
  • plasma-mobile

Running Plasma Mobile UI on framebuffer backend

See Plasma_Mobile#Software_rendering

Photos

Additional info

Partition list

Partition list

Device Label Size in blocks Size in bytes Stock FS
mmcblk0p1 switch 8 8192
mmcblk0p2 dpo 8 8192
mmcblk0p3 fsc 8 8192
mmcblk0p4 limits 32 32768
mmcblk0p5 ssd 32 32768
mmcblk0p6 sec 20 20480
mmcblk0p7 vbmeta 64 65536
mmcblk0p8 vbmetabak 64 65536
mmcblk0p9 storsec 128 128K
mmcblk0p10 storsecbak 128 128K
mmcblk0p11 apdp 256 256K
mmcblk0p12 msadp 256 256K
mmcblk0p13 keystore 512 512K
mmcblk0p14 frp 512 512K
mmcblk0p15 rpm 512 512K
mmcblk0p16 rpmbak 512 512K
mmcblk0p17 hyp 512 512K
mmcblk0p18 hypbak 512 512K
mmcblk0p19 pmic 512 512K
mmcblk0p20 pmicbak 512 512K
mmcblk0p21 cmnlib 1024 1024K
mmcblk0p22 cmnlibbak 1024 1024K
mmcblk0p23 cmnlib64 1024 1024K
mmcblk0p24 cmnlib64bak 1024 1024K
mmcblk0p25 abl 1024 1024K
mmcblk0p26 ablbak 1024 1024K
mmcblk0p27 dip 1024 1024K
mmcblk0p28 ddr 1024 1024K
mmcblk0p29 toolsfv 1024 1024K
mmcblk0p30 devcfgbak 1024 1024K
mmcblk0p31 devcfg 1024 1024K
mmcblk0p32 tz 4096 4096K
mmcblk0p33 tzbak 4096 4096K
mmcblk0p34 mdtpsecapp 4096 4096K
mmcblk0p35 mdtpsecappbak 4096 4096K
mmcblk0p36 keymaster 1024 1024K
mmcblk0p37 keymasterbak 1024 1024K
mmcblk0p38 bluetooth 1024 1024K vfat
mmcblk0p39 lsti 2048 2048K
mmcblk0p40 xbl 3584 3584K
mmcblk0p41 xblbak 3584 3584K
mmcblk0p42 misc 4096 4096K
mmcblk0p43 devinfo 8192 8192K
mmcblk0p44 logfs 8192 8192K
mmcblk0p45 fsg 8192 8192K
mmcblk0p46 modemst1 8192 8192K
mmcblk0p47 modemst2 8192 8192K
mmcblk0p48 dsp 16384 16.0M vfat
mmcblk0p49 bk1 24576 24.0M
mmcblk0p50 mdtp 32768 32.0M
mmcblk0p51 bk2 16384 16.0M
mmcblk0p52 dtbo 8192 8192K
mmcblk0p53 dtbobak 8192 8192K
mmcblk0p54 splash 65536 64.0M
mmcblk0p55 persist 32768 32.0M ext4
mmcblk0p56 persistbak 32768 32.0M ext4
mmcblk0p57 logdump 65536 64.0M
mmcblk0p58 modem 196608 192M vfat
mmcblk0p59 rawdump 131072 128M
mmcblk0p60 boot 65536 64.0M
mmcblk0p61 recovery 65536 64.0M
mmcblk0p62 cache 262144 256M ext4
mmcblk0p63 system 3670016 3584M ext4
mmcblk0p64 vendor 2097152 2048M ext4
mmcblk0p65 cust 851968 832M ext4
mmcblk0p66 userdata 22802415 21.7G encrypted (dm-0)
mmcblk0rpmb 4096

Android Verified Boot (vbmeta)

This device is using Android_Verified_Boot_(AVB) so, if you did not flash any custom Android ROM, you may need to flash vbmeta partition with vbmeta.img with verification disabled flag. pmbootstrap now can generate such empty vbmeta image and flash it with one command:

$ pmbootstrap flasher flash_vbmeta

DTBO partition

This device is using a dedicated partition to store the Device Tree Blob Overlay. Read more at https://source.android.com/devices/architecture/dto/partitions .

Update: looks like dtbo partition is not used during boot by LineageOS's kernel, because it is using appended DTB (CONFIG_BUILD_ARM64_APPENDED_DTB_IMAGE=y)

Update2: device tree from dtbo partition is used by bootloader to apply some fixups on top of appended dtb. Bootloader tries to apply overlay dtb from dtbo partition over a dtb found appended to kernel, and if it fails to do so, it falls back into fastboot mode. Example bootloader debug UART output in that case:

Memory Base Address: 0x40000000
Decompressing kernel image start: 2700 ms
Decompressing kernel image done: 2852 ms
ufdt apply overlay failed
Launching fastboot

See also Zhuowei's notes on creating custom dtbo partition: https://gitlab.com/zhuowei/dtbo-google-crosshatch-mainline

For mainline kernel just fastboot erase dtbo works. Bootloader ignores missing dtbo, example output when dtbo partition is erased:

Memory Base Address: 0x40000000
Decompressing kernel image start: 2641 ms
Decompressing kernel image done: 2793 ms
Dtbo hdr magic mismatch 0, with D7B7AB1E
Best match DTB tags 317/00020008/0x00000000/0/1001B/102001A/0/0/(offset)0x97128304/(size)0x00000653
Using pmic info 0x1001B/0x102001A/0x0/0x0 for device 0x2001B/0x102001A/0x0/0x0
Memory Base Address: 0x40000000
smem protocol = 9C2FA0A0
board_id1 is 1
 board_id2 is 1
 board_id3 is 0
board_id is 1
get_boardid_from_smem,SUCCESS ,board_id=0x102,cpu_id=0x39148C8C,hwdefined=0
 PON Reason is 17 cold_boot:1 charger path: 1
...(proceeding to normal boot procedure)...

For downstream kernel, leave stock dtbo partition untouched.

Bootloader cmdline

Stock bootloader is doing nasty things with kernel command line: it passes a lot of arguments that make booting custom OS (like postmarketOS) impossible

Full list of stock command line parameters:

ramoops_memreserve=4M

rcupdate.rcu_expedited=1
console=ttyMSM0,115200,n8
androidboot.console=ttyMSM0
earlycon=msm_serial_dm,0xc170000
androidboot.hardware=qcom
user_debug=31
msm_rtb.filter=0x37
ehci-hcd.park=3
lpm_levels.sleep_disabled=1
sched_enable_hmp=1
sched_enable_power_aware=1
service_locator.enable=1
swiotlb=1
firmware_class.path=/vendor/firmware_mnt/image
loop.max_part=7
androidboot.selinux=permissive
buildvariant=eng

androidboot.verifiedbootstate=orange
androidboot.keymaster=1
root=PARTUUID=2a7f6d6d-1c23-febe-7efb-9ccfa1432ace
androidboot.bootdevice=c0c4000.sdhci
androidboot.serialno=ac1dde4e
androidboot.cpuid=0x39148c8c
androidboot.dp=0x0
androidboot.baseband=sdm
mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_nt36672a_tianma_fhdplus_video:config0:1:none:cfg:single_dsi
skip_initramfs
rootwait
ro
init=/init
androidboot.dtbo_idx=0
androidboot.fpsensor=fpc
androidboot.secureboot=1
androidboot.hwc=Global
androidboot.hwversion=1.29.0
androidboot.hwlevel=MP
androidboot.hwdevice=lavender

ramoops_memreserve=4M comes from defconfig, next from boot.img, others (starting with first androidboot. and below) come from bootloader directly.

Harmful kernel command line params from bootloader

Options like root=, skip_initramfs make kernel look for a specific partition to mount at /, skipping initramfs, which is incompatible with default booting methods of postmarketOS. That's why some tricky patches are needed, similar to ones used by Zhuowei in Google Pixel port: 1, 2.

Another hack to fix bootloader cmdline params by opendata26: init: ignore bootloader cmdline params for mounts

Some info on skip_initramfs kernel cmdline parameter: https://forum.xda-developers.com/apps/magisk/pixel-2-pixel-2-xl-support-t3697427/post74361728#post74361728

Way to get boot log

This device known to ship with the oem getlog fastboot command.

This is not a trivial command to use, but it is extremely useful as it allows side-stepping the need to boot in a known working system to use the ramoops console. The output of the command is a jumble, but is still usable for figuring out early boot issues. It is much better than having to rely on a booted system to get the information, but still not as good as having a dedicated serial access.

Example usage follows.


$ fastboot oem getlog 2>&1
(bootloader) [    0.000000] Booting Linux on physical CPU 0x0
[    0.000
(bootloader) 000] Initializing cgroup subsys cpuset
[    0.000000] Initi
(bootloader) alizing cgroup subsys cpu
[    0.000000] Initializing cgrou
(bootloader) p subsys cpuacct
[    0.000000] Initializing cgroup subsys
(bootloader) schedtune
[    0.000000] Linux version 4.4.153 (nixbld@loca
(bootloader) lhost) (gcc version 4.9.4 (GCC) ) #2 SMP PREEMPT Sat Nov 23
(bootloader)  20:31:33 UTC 2019
[    0.000000] Boot CPU: AArch64 Process
(bootloader) or [51af8014]
[...]


As the output of the command is on stderr, here's how to output to a file.


$ fastboot oem getlog > log.txt 2>&1


It is unknown if there are ways to make the output better. (Apply some kind error correction algorithm?)

EDIT: seems to not work for me, whatever you do, the output is:

$ fastboot oem getlog
                                                  (bootloader) [Macle]Maybe no last kmsg
OKAY [  0.000s]
Finished. Total time: 0.000s

Probably needs a crash? But I can read pstore-console (dmesg) logs from booted TWRP recovery fine..

Xiaomi Redmi Note 7 (lavender) UART test pins schematic
Xiaomi Redmi Note 7 (lavender) UART test pins photo

Getting logs through debug UART

You have to disassemble the phone (just removing back cover is enough). You'll have to heat up edges of the back cover (as shown in disassembling video, see Links below) before trying to remove it. Be careful! It is made of glass! Also be careful about fingerprint sensor connector, it is connected to a back cover you are trying to remove. Don't rip it.

In the center you will see 4 test points that are available. (See the picture) Two bigger ones (0.8mm) are EDL (FORCE_USB_BOOT) pins. UART test points are two smaller ones on the left (0.5mm). TP11 is UART TX (gpio 4), TP10 is UART RX (gpio 5). GND is that whole metal shielding, that covers the center of the board. So, to get debug logs from UART it is enough to connect UART TX from the board to RX pin on the converter, and connect GND between phone and GND pin on the converter.

Links