plat/arm/board/arm_fpga: Use preloaded BL33 alternative boot flow
This makes use of the PRELOADED_BL33_BASE flag to indicate to BL31 that
the BL33 payload (kernel) has already been loaded and resides in memory;
BL31 will then jump to the non-secure address.
For this port the BL33 payload is the Linux kernel, and in accordance
with the pre-kernel setup requirements (as specified in the `Booting
AArch64 Linux' documentation:
https://www.kernel.org/doc/Documentation/arm64/booting.txt),
this change also sets up the primary CPU's registers x0-x3 so they are
the expected values, which includes the address of the DTB at x0.
An external linker script is currently required to combine BL31, the
BL33 payload, and any other software images to create an ELF file that
can be uploaded to the FPGA board along with the bit file. It therefore
has dependencies on the value of PRELOADED_BL33_BASE (kernel base) and
the DTB base (plus any other relevant base addresses used to
distinguish the different ELF sections), both of which are set in this
patch.
Signed-off-by: Oliver Swede <oli.swede@arm.com>
Change-Id: If7ae8ee82d1e09fb05f553f6077ae13680dbf66b
1 file changed