Memory address 0x0 is invalid

[hyperion009]

Hi My riscv core is used in a kind of specific suitation. The program's address linked by ld is to be at 0x0. However, I got following error messages: Access exception occurred while loading payload hmrv_core_arithmetic_basic_test_0.o: Memory address 0x0 is invalid

what else can I do to work around this issue?

thanks in advance.

[liweiwei90]

The default DRAM_BASE is 0x80000000. You can specify memory layout by "-m" option.

[scottj97]

I believe Spike has a debug ROM at 0. You might have to disable the external debug feature, which would require source code changes to Spike.

[hyperion009]

@liweiwei90 thanks, something like -m 0x0:64, right?

[hyperion009]

@liweiwei90 I appended -m 0:64 to spike and got a message: Warning: the memory at [0x0, 0x3F] has been realigned to the 4 KiB page size: [0x0, 0xFFF] Access excpetion occurred while loading payload hmrv_core_arithmetic_basic_test_0.o: Memory address 0x0 is invalid

[hyperion009]

@scottj97 thanks scott， I am a newbie to spike. Could you provide more details on this, it's better to show me an example.

[scottj97]

I'm afraid I don't know much about the debug hardware that's modeled in Spike, but it might be as simple as removing the debug device here

[scottj97]

Or changing DEBUG_START to point to somewhere else.

[timsifive]

Or changing DEBUG_START to point to somewhere else.

A quick test shows that this breaks debugging.

[scottj97]

A quick test shows that this breaks debugging.

Not surprising. I'm assuming since OP has program code residing at address 0, he doesn't care about debugging.

[hyperion009]

@scottj97 @timsifive thanks Scott&Tim. @timsifive what kind of broken debugging issues show up?