SPRADK8 February   2025 AM62P

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Hardware Used
    1. 2.1 AM62Px Processor
    2. 2.2 SK-LCD1
    3. 2.3 Display Subsystem on AM62P
  6. 3Early Splash-Screen Architecture
    1. 3.1 Boot Stages on AM62P
    2. 3.2 Flicker-Free Transition
  7. 4Flicker-Free Transition From SPL to U-Boot
    1. 4.1 Steps to Test
    2. 4.2 Measurements
  8. 5Flicker-Free Transition From SBL to Linux Kernel
    1. 5.1 Steps to Test
    2. 5.2 Measurements
  9. 6Results

4.1 Steps to Test

This section describes the steps required to achieve an early splash screen, along with flicker-free transition from the SPL stage to U-Boot. The splash screen support from A53 SPL is provided out-of-the-box in the Linux version 9.0 Software Development Kit (SDK) onwards. By default, the splash screen is only enabled at A53 SPL. The default splash source was set to an SD card and displays a gzip TI logo .bmp image. The SPL splash screen features are compiled in the tispl.bin which is built during U-Boot compilation. Any changes made to the SPL splash screen feature requires recompiling tispl.bin. Use the new tispl.bin to boot the board to see the splash screen at the SPL stage.


AM62P Splash Flow

Figure 4-1 Splash Flow

All information related to splash screens is stored in a board.env file, board/ti/am62px.env contains all the splash-related variables for the AM62P device:

splashfile=ti_logo_414x97_32bpp.bmp.gz 
splashimage=0x80200000 
splashpos=m,m 
splashsource=mmc
  1. Instructions for displaying a custom logo:

    To display a custom logo update the splash file with the file name of the custom logo. In a case where the AM62P splash source is MMC (this refers to SD card boot media) to replace the image copy the new splash image in the boot partition of the SD card.

    Note: U-Boot only supports .bmp and compressed .bmp images.
  2. Instructions for changing boot media:

    The splash_source struct defined in board/ti/am62px/evm.c defines the different sources from which the splash image can be displayed.

    static struct splash_location default_splash_locations[] = {
    {
        .name = "sf",
        .storage = SPLASH_STORAGE_SF,
        .flags = SPLASH_STORAGE_RAW,
        .offset = 0x700000,
    },
    {
        .name = "mmc",
        .storage = SPLASH_STORAGE_MMC,
        .flags = SPLASH_STORAGE_FS,
        .devpart = "1:1",
    },
};

To change the splash source, update the splashsource variable in board.env file with the variable name of the sources defined in the default_splash_locations struct. AM62P supports two boot medias; "sf" refers to Octal Serial Peripheral Interface (OSPI) and "mmc" refers to an SD card. Use one of the boot media from the sources defined. To use a different boot media, add the information in the struct and update the splashsource with the name of the new boot media.