LAW Config: PCIe0 --- 0xf80000000
Core hang during read address 0xf80000000. It looks like an unrecoverable error while accessing the address.
It is normal that Machine Check is generated when a PCIe read transaction addressed memory region assigned to a target device which is not present.
In this case no valid data can be returned, so asynchronous Machine Check is generated.
> What is the correct CPU response when accessing 0xf80000000?
What is mapped to this address?
Please provide U-Boot booting log.
ufedor, Thanks for your replay!
>What is mapped to this address?
I just specify the address 0xf80000000(it could be any other address) as PCIe space through LAW and no real PCIe device assigned to this address.
Not clear, I'm asking for this because I caught the machine check exception on T2080RDB CPU version 1.1 but CPU hanged on T2080RDB CPU version 1.0, T2080QDS and T4240QDS.
>In this case no valid data can be returned, so asynchronous Machine Check is generated.
I think this is the real reason for this problem, accessing the PCIe address without a hardware populated may cause an asynchronous MCK.
And does the asynchronous MCK will cause CPU to hang?
> And does the asynchronous MCK will cause CPU to hang?
Please use a debugger to determine what the processor is doing during the hang state.
Please consider that it could be a read instruction which can't be completed because a valid data is not provided.
I have done that before and that is why i have posted this question page. When a load assembly instruction "lwz r6,0(r5)" (reading address 0xf80000000)was executed, the CodeWarrior TAP was disconnected and the value of registers MSR/MCSR and other status registers changed to meaningless. And the core has no response anymore.
However thanks for your replay.
Root Cause :
OB_CK bit of PCI Express Configuration Register (PEX_CONFIG offset is 0x14) was not set.
Retrieving data ...