Hi,
I am planning to boot ARM A-78 core with Linux.I have gone through some documents and ended up with below understanding of cortex ARM-A78's boot process:
ARM A-78 Core Reset => BootROM => 1st stage BootLoader => 2nd stage BootLoader => Kernel Image
Is my understanding correct or I have missed something ?
If this is the case, can any one help me for BootROM code ?Like,
- from where to get the source code of BootROM ? - How to develop one by our self ?
If this isn't the case, please help me understand it better.
Thanks You,Maunik Patel
Which chip, or SoC are you talking about? I recommend to read the TRM of the SoC, it (in general) explains the boot process.
I am not using any SoC or Chip.There is a DDR RAM with ARM A78 core and a interconnect between them.No other peripherals are attached with the core, for now.I will store the boot Code in this DDR RAM, for now, and wish that ARM A78 will execute that code.I am not clear exactly, what should be there in the boot code.I need some example boot code or some help to develop one.If I am not clear, please feel free to inform me.I will be happy to explain.
Are you talking about a simulation or ASIC?!
Anyway, the Cortex-A starts at address zero or 0xffff0000 if high-vector is set. So place your code there.
It is true for v7-A or armv8-A with aarch32 EL3 that Cortex-A starts at address zero or 0xffff0000 if high-vector is set. For armv8-A processors, there are some hardware signals that decide EL3 is aarch32 or aarch64, and where CPU fetches the first instruction (start address) with aarch64 EL3.
I am talking about the simulator.
Thanks,
Neel Desai