Question about DTB in Mini-OS on ARM

[Chen Baozi <baozich@gmail.com>]

Hi Ian,

I've turned to arm32 porting of Mini-OS as you suggested. Right now, I've
finished most of entry header, which setups an initial page table, saves
DTB pointer (from r2 which arm booting protocol defines), setups the stack
before jumping to start_kernel, and includes the exception's entry.

At this stage, I could get the DTB's address in arch_init(), parse it and
translate it to fill start_info structure Mini-OS used. In order to
implement this logic, I was seeking and reading DTB's related codes of
arm guest creation and found that the DTB used in domU in arm is thought
to be appended with the guest kernel:

	/*
	 * ATAGS/DTB: We currently require that the guest kernel to be
	 * using CONFIG_ARM_APPENDED_DTB. Ensure that r2 does not look
	 * like a valid pointer to a set of ATAGS or a DTB.
	 */

In this case, I cannot get the DTB's phys address to fill start_info from
r2 currently. Does it means we need to wrap the mini-os kernel together with
a DTB?

Any ideas?

Thanks.

	Baozi