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Altera_Forum's avatar
Altera_Forum
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10 years ago

Bus error when trying to write to memory

Hi

I use cycone V board with 2GB Micron sdram, i cofigure the preloader and u-boot to have 2GB sdram also.

I cant write with memtool to address from 0x80000000 to 0xc0000000 - i have Bus error massage

If i write to other address i do not have error

root@socfpga_cyclone5:~# echo 1 > /sys/class/fpga-bridge/lwhps2fpga/enable

root@socfpga_cyclone5:~# echo 1 > /sys/class/fpga-bridge/hps2fpga/enable

root@socfpga_cyclone5:~# echo 1 > /sys/class/fpga-bridge/fpga2hps/enable

root@socfpga_cyclone5:~# memtool -32 0x80000000=0x00200100

Writing 32-bit value 0x200100 to address 0x80000000

[ 6839.386707] Unhandled fault: external abort on non-linefetch (0x1818) at 0x76fd3000

Bus error

And i know it is related to preloader only (if i use older preloader - 13.1 or 14.0 it works O.K, the problem appears if i use 14.1 or 15.0, i dont change the other boot files DTB,ZIMAGE...)

With QSYS i configure AVALONE 32 bit FPGA to HPS interface, Number of chip select/depth expansion: 2

My linux Kernel ver is 3.18

attached my boot log when using preloader generated with SoCEDS14.1

thanks a lot

Otzri Yehuda

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    A couple of things to check before you access physical address 0x8000_0000:

    1) You have configured the FPGA before you go to access this location right? That location is the H2F bridge

    2) Double check that the bridge is mapped into the address space, there is a remap register in the L3 at address 0xFF80_0000 and if the H2F bridge is mapped properly then bit 3 should be set. If the bridge isn't mapped then you should expect an abort.