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Altera_Forum
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12 years ago

Cyclone V - How to split DDR3 memory for HPS and FPGA?

Hello everybody, I have an EBV SoCrates Board (Cyclone V) with me. I want to devide the external DDR3 memory into 3 partiions. One partition for linux/hps, one partition for the fpga and a...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Hi Guinea, I managed to create 2 partitions on the HPS SDRAM - 1 for the Linux operating system, the other for exclusive use by the FPGA. You can take a look at: https://support.criticallink.com/redmine/projects/mityarm-5cs/wiki/writing_to_hps_memory for an excellent tutorial on how to do this. The magic is in setting the bootloader argument as follows:

  • setenv mmcboot 'setenv bootargs console=ttyS0,115200 root=${mmcroot} rw rootwait mem=512M;bootz ${loadaddr} - ${fdtaddr}'

  • saveenv

The above partitions 512MB of the SDRAM for Linux usage. The other 512MB is free for the FPGA to use and starts at address 0x3000_0000 for the Cyclone V SOC. Hope this helps! :)