U-Boot Splash Screen

Introduction

On this page you will learn how to activate LCD support in U-Boot and display a Splash Screen at boot.

Note: The following instructions have only be tested on OPOS6UL.

Installation

• Save your image as BMP file (in Gimp use Run-Length (RLE) encoding, no alpha channel and no color informations (compatibility options))
• Activate LCD in U-Boot (here ST0700):

BIOS> setenv videomode video=ctfb:x:800,y:480,depth:18,pclk:33033,le:8,ri:4,up:2,lo:4,hs:64,vs:4,sync:0,vmode:0

Test it

BIOS> tftpboot ${loadaddr} xxx.bmp
BIOS> bmp info ${loadaddr}
Image size    : 296 x 72
Bits per pixel: 8
Compression   : 0

BIOS> bmp display ${loadaddr} 100 50

Deploy it

• Here we assume that logo is stored in /boot directory of rootfs eMMC partition as logo.bmp:

BIOS> setenv splashimage 0x80000000
BIOS> setenv splashfile /boot/logo.bmp
BIOS> setenv splashsource mmc_fs

Continuity with Linux Boot Logo

• If you want Linux to keep your U-Boot Logo during boot process, then some tweaks are needed:
  • define CONFIG_SYS_MEM_TOP_HIDE in U-Boot configuration file, here we reserve 2MBytes:

    #define CONFIG_SYS_MEM_TOP_HIDE         (2 << 20)
    

• Force framebuffer RAM address in U-Boot LCD driver (OPOS6UL has 256MBytes (0x10000000) RAM starting at physical 0x80000000):

  @@ -197,8 +197,8 @@
   	panel.memSize = mode.xres * mode.yres * panel.gdfBytesPP;
   
   	/* Allocate framebuffer */
  -	fb = memalign(ARCH_DMA_MINALIGN,
  -		      roundup(panel.memSize, ARCH_DMA_MINALIGN));
  +	fb = (void *)0x8fe00000; /*memalign(ARCH_DMA_MINALIGN,
  +		      roundup(panel.memSize, ARCH_DMA_MINALIGN));*/
   	if (!fb) {
   		printf("MXSFB: Error allocating framebuffer!\n");
   		return NULL;
  

• Tell Linux to not print cursor on Framebuffer and to not use last 2M of RAM:

  BIOS> setenv extrabootargs vt.global_cursor_default=0 mem=248M

• Force framebuffer RAM address to same value in Linux LCD driver:

  @@ -825,17 +824,18 @@
          var->vmode = FB_VMODE_NONINTERLACED;
  
          /* Memory allocation for framebuffer */
  +#define FORCED_FB_ADDR 0x8fe00000
          fb_size = SZ_2M;
  -       fb_virt = dma_alloc_wc(dev, PAGE_ALIGN(fb_size), &fb_phys, GFP_KERNEL);
  +       fb_virt = ioremap_wc(FORCED_FB_ADDR, fb_size);
          if (!fb_virt)
                  return -ENOMEM;
  
  +       fb_phys = FORCED_FB_ADDR;
          fb_info->fix.smem_start = fb_phys;
          fb_info->screen_base = fb_virt;
          fb_info->screen_size = fb_info->fix.smem_len = fb_size;
  
  -       if (mxsfb_restore_mode(host, vmode))
  -               memset(fb_virt, 0, fb_size);
  +       mxsfb_restore_mode(host, vmode);
  
          return 0;
   }
  

• Reflash all that on your board and... That's it ! ;-)

Links

• http://www.denx.de/wiki/DULG/UBootSplashScreen