[Qemu-discuss] Vector table and memory allocating vexpress-a9

[Mirela Simonović]

Hi,

I don't have mush experience with Qemu, any help would be appreciated.

I'm using vexpress-a9 platform and qemu-1.0.1 version.

I know that on real Vexpress ARM platform Vector Table should be placed at the address 

0x0 or at 0xFFFF0000, depending on the  VINITHI signal. 

How this works on Qemu and at which address Vector Table begins?

I thought I can come to the conclusion where is the start address

of the Vector Table with the following:

I instantiated one CPU, 1 GB memory (-m 1024 option), 

my code starts from the address 0x60030000. 

I attached gdb and tried to fill the memory from the addresses 0x0 and

0xFFFF0000 with 7 x "B ." instructions (typing "set *0x0=..."). 

That should be easy way to capture interrupt (without additional interrupt handling).

But write to 0xFFFF0000 is ignored (after write I read zeros).

At which addresses Qemu is allocating 1 GB memory?

Branch to reset vector in my code is placed at address 0x60030000, and it works.

I guess that is because Qemu sets PC start address and therefore bootloader is not needed?

Can you please give me some explanations/advices that is actually happening?

Thanks,

Mirela