Access to PCIe via M7 or u-boot on iMX8

[Hideo_Noda]

Hi, I am trying to access PCIe Registers at 0x33800000 on iMX8PLUS via the M7 core before the Linux boots, but reading a PCIe register hangs M7.
M7 can successfully read the PCIe registers after the Linux booted.
Reading the register by u-boot freezes the A53Core as well.
What configuration is needed before access to the PCIe registers without Linux?

[weidong_sun]

Hi,

See the following, please!

1. put cpu is in Serial download mode

2. using debugger link M7 core

3. try to access register of PCIe in your application

Try it, please!

Have a good day!

Regards,

weidong