The splash video feature can be used to display a video while the system is booting to the operating system. This section describes how to configure the options needed.
Splash Video with 8 MB of Stolen Memory Example
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The Video DMA area is where the video will be streamed. It is part of the stolen memory of our graphics device.
The external PCIe device that is connected to the camera needs to know the exact DDR RAM physical address to stream, or dump the video data at that memory location.
To calculate the Start DDR RAM physical address:
Start_Phy_Ram_Addr = BGSM + Video_Offset
where BGSM = Base of Graphics Stolen Memory
and Video_Offset = Offset where the video data is present. This is what you enter into the CED tool.
There are two ways to calculate BGSM:
• The recommended method is to use the setpci command in Linux to find the BGSM from the PCIe Config space.
At the Linux command prompt, type the following:
• Find the amount of physical RAM populated in the system, for example, 1 GB, and the stolen memory selected by the user in the system BIOS, for example, 8 MB.
BGSM = 1 GB - 8 MB = 0x4000 0000 - 0x80 0000 = 0x3F80 0000
How to Select the Video_Offset
Determine the size of the maximum resolution of the framebuffer.
Size = framebuffer_height * framebuffer_pitch
where framebuffer_pitch = framebuffer_width * Bytes_per_Pixel (page aligned)
For example, 1024x768 at 32-bit BPP:
Size = 768 * (1024 * 4) = 3145728 = 0x30 0000
For some usage models, the framebuffer pitch is set to 8192 bytes. In that case:
Size = 768 * (8192) = 6291456 = 0x60 0000
The Video_Offset can start from 0x30 0000 or 0x60 0000 (if the pitch is 8192). See the notes below on the recommended values for the Video Offset.
1. For the Splash Video option the stolen memory MUST be a minimum of 8 MB. This is selected in the BIOS menu.
2. The recommended Video Offsets for the splash video are 0x600000 and 0x700000.
3. If the Size of the Video frame is more than 1 MB, please choose 0x600000.