How does memory work

https://en.wikipedia.org/wiki/Input%E2%80%93output_memory_management_unit

Example of kernel driver

• From linux https://github.com/Xilinx/linux-xlnx/blob/master/drivers/dma/dmatest.c

• Sunxi dma https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/dma/sunxi-dma.c

HW (device tree)

https://github.com/torvalds/linux/blob/master/arch/arm/boot/dts/sun8i-h2-plus-orangepi-zero.dts

https://github.com/ARM-software/u-boot/blob/master/arch/arm/dts/sun8i-h3.dtsi

Main documentation

https://linux-sunxi.org/H3#Variants

Similar poject for RPI

• Example copy memory to memory https://github.com/Wallacoloo/Raspberry-Pi-DMA-Example/blob/master/dma-example.c

• Example copy IO to memory https://github.com/Wallacoloo/Raspberry-Pi-DMA-Example/blob/master/dma-gpio.c

Block Diagram of engine

Current output

For now simple mem2mem works

H2 data-sheet important pages

• Clock domains are visible on page: 88
• DMA bloc clock domain: 191

Video codec

http://linux-sunxi.org/Cedrus