Given this UART bootloader log from xiaomi whyred sdm636, infer everything that's going on, especially how it's doing panel detection:

UEFI Start     [  850] SEC
PROD Mode   : On
DEBUG Mode : On
ASLR        : On
Timer Delta : +7 mS
RAM Entry 0 : Base 0x0000000040000000  Size 0x0000000060000000
RAM Entry 1 : Base 0x00000000A0000000  Size 0x000000005EAC0000
UEFI Ver    : 4.2.191023.BOOT.XF.1.4-00262-S660LZB-1
Build Info  : 64b Oct 23 2019 20:51:12
Boot Device : eMMC
DALLOG Device [0x2000145]: Cannot turn on source[ACPL
Elapsed tick: 0x126EC2E, Wait tick: 0x36EE800 
Setvariable returned Success
IsPressPwrKeyOn: true
zjl  haptic_on
zjl  haptic_off
[CheckPanel] panel reg[0xc] value: 0x00000077, uReponseSize:2
Panel_CDP_GetID: temp1 =0;temp2 =0
readback: i=0  val=0x0
readback: i=1  val=0x0
readback: i=2  val=0x0
readback: i=3  val=0x0
readback: i=4  val=0x0
readback: i=5  val=0x0
readback: i=6  val=0x0
readback: i=7  val=0x0
Display:e7s tianma td4310!
ReadKeyInternal: gEfiSimpleTextInputExProtocolGuid handles = 3
ReadKeyInternal: Read KEY = 0x102
 bootstate = 0
PanelWidth=1080,PanelHeight=2160
ImageWidth=1080,ImageHeight=2160,LogoPosX=0,LogoPosY=0
Avoid flicking for 2160x1080 images 
PanelWidth=1080,PanelHeight=2160
Render Splash  [ 3666]
EnvDxe Render Callback
LoadImageFromPartitionUsingGuid Failed: 14
Keymaster failed to load! Status = 0xE
LoadSecureApps: Load app from partition(keymaster): Status = 0x0, AppId = 65537
APC1 IDDQ WC 0 , L2:0, CPU[0]:175, CPU[1]:175, CPU[2]:175, CPU[3]:175
 APC1 Total 700
-----------------------------
Platform Init  [ 3832] BDS
UEFI Ver   : 4.2.191023.BOOT.XF.1.4-00262-S660LZB-1
Platform   : MTP
Chip Name  : SDM636
Chip Ver   : 1.0
Core 0 Freq: 1382400 MHz
-----------------------------
zjlz 0000 QcomChargerApp:: ChargerLib_ChargerEnable Error getting platform type  
zjlz 3333 QcomChargerApp:: ChargerLib_Exit Error getting platform type  
UEFI Total : 4066 ms
POST Time      [ 4916] OS Loader
Loader Build Info: Oct 23 2019 21:41:24
VB: RWDeviceState: Succeed using rpmb!
KeyPressed = (0x102)
Reboot reason: 0
E7S Platform Version : 0x30000
Booting Into Mission Mode
Loading Image Start : 4933 ms
Loading Image Done : 4933 ms
Total Image Read size : 512 Bytes
Loading Image Start : 4933 ms
Loading Image Done : 5023 ms
Total Image Read size : 15347712 Bytes
No dtbo partition is found, Skip dtbo
VB: DeviceInit: Device is unlocked! Skipping verification!
ReadKeyInternal: gEfiSimpleTextInputExProtocolGuid handles = 3
ReadKeyInternal: Read KEY = 0x0
 bootstate = 4
var = UNLOCK splash update
Cannot find GraphicsHandles.
ImageWidth=1080,ImageHeight=2160,LogoPosX=0,LogoPosY=0
Avoid flicking for 2160x1080 images 
Cannot find GraphicsHandles.
Render Splash  [ 5089]
VB: VerifyImage: Image verification done! boot state is: ORANGE
Display menu is not enabled!
Device is unlocked, Skipping boot verification
VB2: BootState = 1
ReadKeyInternal: gEfiSimpleTextInputExProtocolGuid handles = 3
ReadKeyInternal: Read KEY = 0x0
 bootstate = 4
var = UNLOCK splash update
Cannot find GraphicsHandles.
ImageWidth=1080,ImageHeight=2160,LogoPosX=0,LogoPosY=0
Avoid flicking for 2160x1080 images 
Cannot find GraphicsHandles.
Render Splash  [ 5161]
VB2: RenderSplashScreen end , BootState = 4 
No Ffbm cookie found, ignore: Not Found
Memory Base Address: 0x40000000
Decompressing kernel image start: 5164 ms
Decompressing kernel image done: 5610 ms
BootLinux: failed to get dtbo image
Best match DTB tags 345/00030008/0x00000000/0/1001B/102001A/0/0/(offset)0x9AB6A18B/(size)0x00063FA2
Using pmic info 0x1001B/0x102001A/0x0/0x0 for device 0x2001B/0x102001A/0x0/0x0
Memory Base Address: 0x40000000
smem protocol = 9C2FF0A0
board_id1 is 1
 board_id2 is 0
 board_id3 is 0
board_id is 0
get_boardid_from_smem,SUCCESS ,board_id=0x102
 PON Reason is -1347440768 cold_boot:1 charger path: 0
GetCheckPanelPressGuid:checkPanel = 0x1;Status:0x0
panel is Exist
VBRwDevice failed with: 00000050
Error Enabling charger screen: 00000050
get_hwconfig_cmdline, board_id=0x102
get_hwconfig_cmdline, hwlevel=0x0
get_hwconfig_cmdline, maxcount=0x32
aaaaaa
get_hwconfig_cmdline, i=0x4
Cmdline: 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 androidboot.configfs=true androidboot.usbcontroller=a800000.d
RAM Partitions
Add Base: 0x0000000040000000 Available Length: 0x0000000060000000 
Add Base: 0x00000000A0000000 Available Length: 0x000000005EAC0000 
WARNING: Could not find mem-offline node.
kaslr-Seed is added to chosen node
pureason = 40080

Shutting Down UEFI Boot Services: 5700 ms
BDS: LogFs sync skipped, Unsupported
App Log Flush : 2384 ms
Exit BS        [ 8100] UEFI End