MT6735 platform, can boot, but the black screen for a long time to see the boot picture.
Check the serial port log found that the phone is normal operation, that is, LCM driver is not abnormal, black screen stage is not any error reported.
Find the following on the MTK FAQ:
[DESCRIPTION]This FAQonly discuss the black screen during boot, do not discuss the flower screen (can refer to the brush). Only the l/m version is discussed (the previous version of KK/JB can be used as a reference).
The first thing to look at is IPO startup, that is, in the setting--> auxiliary function--not tick "fast boot", if not black screen, description is due to the issue of the IPO process, then the problem needs to look at this animation, you can find the IPO animation owner.
If you do not tick "fast boot" appears black screen, then this is the problem we are discussing now.before locating the problem, be sure to understand the time period of the black screen,Because during the boot process, there will be LK Logo,kernel logo,bootanimation, the three screen inside a black screen, the solution is not the same.
The following chart, which is the ENG version of the boot logo, explains the logo display during the boot process. View the issue,Be sure to use the ENG version, as the Eng version is powered on with a line of "normal boot" in the lower left corner, so we can know where the black screen takes place. The best use of different logo resources, some customers to the LK logo and kernel logo made, bootanimation the first few pictures are also made, not easy to distinguish, so easy to judge error.
As explained below:
(Stage 1), the LK logo with "Normal boot" will be displayed in the LK stage. The display time is generally about 1s.
(phase 2), start to kernel of the first 7s or so, the display is "normal boot" the words of the LK logo. (The l/m version and the KK/JB version are very different here, do not elaborate here)
(Stage 3), after the display kernel logo time period is very short, generally only about 2s.
(Stage 4), display bootanimation animation.
(1) If you suspect kernel log black screen, you can run the kernel log application alone, under normal circumstances will display kernel logo, if there is a black screen, then he caused.
ADB shell
CD System/bin
Boot_logo_updater
(2) Delete the kernel logo separately, you can see if it is not black screen. If not black screen, then may be because the load kernel logo, the bottom of the OVL to brush into the abnormal black screen data or abnormal format data.
ADB remount
ADB shell
CD System/bin
RM-RF Boot_logo_updater
(3) If you suspect bootanimation black screen, you can run the Bootanimation application alone, under normal circumstances will show bootanimation animation, if there is a black screen, then he caused.
ADB shell
CD System/bin
Bootanimation
(4) Delete bootanimation Separately, see if it is still black screen? Not black screen, then the problem is bootanimation, there will be
ADB remount
ADB shell
CD System/bin
RM-RF bootanimation
in the event of a black screen problem, first use the MTK native version and your native logo resource, to see if there is a problem, if the original sound is not a problem, then it may be the customer to replace the logo resources and custom problems, need to pay attention to the following resource checks:
1, the Logo.binsize limit within 4M
2, LK logo and kernel logo image isRGB888 Format
3, bootanimation picture isPNG format
If all of the above check OK, you can see the following ways to locate[Solution]First, if it is (Stage 1) black screen, that is, the LK logo is not displayed, then may be the logo resource anomalies, or the bottom of no brush out, need to catch the UART log view, you canLog trace platform.c file inside the Platform_init () function。
Second, if it is (Stage 1) and (phase 2) between the black screen, may be the problem of the brush screen, if there is an exception, from the UART log, you should be able to see display error, such as VDO mode screen, this time, such as VM done timeout.
Third, if it is (Stage 2) in the middle of the black screen,See if the UART log has display Error/fault/timeout/fail.
Four, if it is (phase 2) and (phase 3) between the black screen, may be due to the loading of the kernel logo abnormal, or MTKFB pan display implementation when the abnormal data entry, usually at this time log inside is difficult to see error, Need to add log in Debug.
Five, if it is (Stage 3) black screen, you can use the above adb command to distinguish whether the kernel logo is the issue or bootanimation start problem.
Note: The above 5 May appear black screen of the stage, are related to the driver layer, in the search for the owner before, please first exclude the logo resource format, such as the custom of the influence. according to our years of positioning problems to summarize, a large part of the customer is due to customized, logo resources and other problems caused . If there is error in log, the data stream is abnormal when the engine is processed, it is easier to correct. If log is not an exception, it may be the exception of the data format or abnormal flow caused by the more difficult to locate.
Six, if it is (stage 4) black screen, run bootanimation application look, if the black screen, then the problem is bootanimation. About bootanimation black screen positioning, the following is a complete summary, please check your own first:
1. For black screen problem first need to confirmquestion of whether the boot animation package itself：
(1) will appear in the black screen mobile phone internal system/media/bootanimation.zip pull to the phone without a black screen problem, check whether there is a black screen,
If the black screen description is the boot animation package itself, can be transferred to AF2 analysis, or continue to find other reasons;
(2) The normal mobile phone system/media/bootanimation.zip pull to the current black screen problems of mobile phones, check whether still black screen.
If there is no black screen description is the issue of the boot animation package itself, can be transferred to AF2 analysis, otherwise continue to find other reasons.
2. TestingRemove the boot ringtoneIf a black screen will also appear after:
If the black screen description does not appear to be related to MediaPlayer initialization, it is necessary to confirm further reasons with the owner of audio. Otherwise, continue to look for other reasons.
For details, refer to [FAQ09563] Boot process kernel logo to boot animation black screen time is too long.
3. A flashing black screen before the boot animation may be related to the default clear screen operation of Google defaults, which requires the removal of code in the BootAnimation.cpp file.
For details, refer to [FAQ14488The]kernel logo flashes a black screen between the boot animations.
[FAQ17969] Boot process kernel logo to boot animation between the black screen (total)
Vii. in addition, for6580/6735 M0.MP1version, appear kernel logo, bootanimation before the black screen problem, please apply patchALPS02561201。
And this one:
[DESCRIPTION]Boot process kernel logo to boot animation between the black screen[Solution]In the boot process, if the Bootanimation.zip picture for a non-black background, found from the kernel logo to bootanimation will be black screen or black screen time is too long, such problems may be related to display, It is also possible to relate to the bootup process. To do this, follow the steps below to perform a preliminary analysis:
1. Confirm which process is black screen:
Uartlog and Mobilelog confirmed is the LK logo, kernel logo, bootanimation which process black screen. If the LK logo, kernel logo, bootanimation the first picture of the same, first the LK logo, kernel logo, bootanimation the first picture is replaced by a different picture.
2. Confirm whether it is an animation package issue:
Cross-Test, exclude animation package bootanimation.zip problem
3. View the Bootanimation process:
3.1 Remove the boot ringtone System/media/bootaudio.mp3, if the black screen still exists, please apply patch in PMS first:ALPS02561201, for M version 6580/6735
Please refer to the following FAQs first:
[FAQ14247] [Denali Series] Pre-boot animation black screen related issues
[FAQ14488] Kernel logo to boot animation between the black screen (L)
If the problem is still unresolved, submit eservice for further analysis and resolution. When submitting EService, please refer to the following FAQ to grab the black screen layer information.
[FAQ05755] How to locate the problem of drawing anomalies such as flower screen and interface disorder?
3.2 Remove the boot ringtone System/media/bootaudio.mp3, from the kernel logo to the animation is no black screen:
It is essential to be sure that the black screen is caused by the time-consuming initialization of MediaPlayer.
The following tests can be performed:
(1) If the mobile phone supports the IPO (fast switch), you can check whether there is a black screen at the time of IPO startup. If there is no black screen, it can be further inferred that the black screen is related to the time-consuming initialization of MediaPlayer.
(2) If the phone does not support the IPO, you can use the ADB command to run Bootanimation bin file test: adb shell system/bin/bootanimation. Conclusion Same as (1).
Please refer to the relevant FAQs first:
[FAQ09563] Boot process kernel logo to boot animation black screen time is too long.
[FAQ17968] New MediaPlayer time-consuming results in the boot process kernel logo to boot animation between the black screen
If the problem is still unresolved, submit eservice for further analysis and resolution.
So, I made the following attempt:
1, with the ENG version boot, did not see the word "normal boot";
2, delete Bootaudio.mp3, still black screen;
3, delete bootanimation.zip, the boot drawing turned into Android, still black screen;
4, confirm the picture format, resolution, etc. are no problem;
Speculation is not related to LCM, which is suspected to be LK and kernel stage LCM backlight is not lit. So configure the LK directory under the CUST_LEDS.C file, configure backlight.
Problem solving.
MTK boot black screen for a long time
