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Hello Marcio,
Yes, there is quite some struggle here... :) At the moment I fell back on an example of CriticalLink (
https://support.criticallink.com/redmine/projects/mityarm-5cs/wiki/writing_to_hps_memory ) (Although I am using the DE0-Nano-SoC, but that shouldn't be an issue.(?))
I Also found a note by CL saying some steps have to be made in order to use the sdram-bridge (
https://support.criticallink.com/redmine/projects/mityarm-5cs/wiki/important_note_about_fpgahps_sdram_bridge). I made a small script in linux that takes care of this after boot:
#!/bin/bash# https://support.criticallink.com/redmine/projects/mityarm-5cs/wiki/Important_Note_about_FPGAHPS_SDRAM_Bridge# start by disabling all fpga-hps bridges
echo =
cat /sys/class/fpga-bridge/*/enable
echo 0 > /sys/class/fpga-bridge/fpga2hps/enable
echo 0 > /sys/class/fpga-bridge/hps2fpga/enable
echo 0 > /sys/class/fpga-bridge/lwhps2fpga/enable
echo =
cat /sys/class/fpga-bridge/*/enable
echo =
memtool -32 0xFFC25080=0x0
echo =
cat /sys/class/fpga/fpga0/status
dd if=P10.rbf of=/dev/fpga0 bs=1M
cat /sys/class/fpga/fpga0/status# at this point, if fpga status is not user mode - program the fpga manually with the programmer
read -p "Should I continue? y/n: " -n 1 -r
echo
if $ ]]
then
cat /sys/class/fpga/fpga0/status
sleep 1
echo =
memtool -32 0xFFC2505C=0x8
echo =
memtool -32 0xFFC25080=0x111
echo
echo 1 > /sys/class/fpga-bridge/fpga2hps/enable
echo 1 > /sys/class/fpga-bridge/hps2fpga/enable
echo 1 > /sys/class/fpga-bridge/lwhps2fpga/enable
cat /sys/class/fpga-bridge/*/enable
echo
memtool -32 0xFFC25080 1
fi
If I'm not mistaken, these steps should take care of everything mentioned by CL. with the only difference being it is done after boot instead of in the preloader ( because I am not yet familiar with making preloaders)
If I start my program after this, the hps will freeze the moment it reaches the descriptor part.
Does any of this ring a bell? :)
Kind regards,
Robin
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Hey, Robin!
The first time I put the system to work I had the same problem, but since it has been a couple of months since I solved it, I don't remember what is the exact solution. However, I can point out some situations so you can debug and see if it works with your design.
# 1 - Add the line "run bridge_enable_handoff;" in your u-boot and compile it again (and put the new u-boot in the sdcard). You can add this line right after the line "setenv bootimage zImage;". This way you can be sure the bridge is enabled.# 2 - Since your HPS freezes, I'm sure# 1 won't be your problem. What I think it happens is that your software messes up with the bridge and the system halts (I ran to the same problem. After the DMA transfered one packet of data I would loose communication with the board). Check if your streaming interface allows "sop" and "eop". If it does, then you have to check on SignalTap if you are generating these signals correctly. It might be a software problem as well... how are you configuring the dispatchers? Paste the code here if u want me to take a look! # 3 - Use SignalTap to see how your transfer starts and ends.
Also, I'm quite sure that you have to enable the bridge communication while booting the device. If you wanna do that, follow this tutorial:
https://rocketboards.org/foswiki/view/documentation/embeddedlinuxbeginnersguide Basically to compile an u-boot you will create a file called "boot.script"" and write this onto it (and other commands u want so you can modify your u-boot)
echo -- Programming FPGA --
fatload mmc 0:1 $fpgadata soc_system.rbf;fpga load 0 $fpgadata $filesize;run bridge_enable_handoff;echo -- Setting Env Variables --setenv fdtimage soc_system.dtb;setenv mmcroot /dev/mmcblk0p2;setenv mmcload 'mmc rescan;${mmcloadcmd} mmc 0:${mmcloadpart} ${loadaddr} ${bootimage};${mmcloadcmd} mmc 0:${mmcloadpart} ${fdtaddr} ${fdtimage};';setenv mmcboot 'setenv bootargs console=ttyS0,115200 root=${mmcroot} rw rootwait; bootz ${loadaddr} - ${fdtaddr}';run mmcload; run mmcboot;
And after doing the previous step you need to compile the script. You can do it by running this command:
mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "Boot Script Name" -d boot.script u-boot.scr
After that replace the u-boot.scr from your sdcard to the one you compiled.
Let me know if this helps or if you have doubts about anything else. Cheers.
Regards!
Honored Contributor
