u-boot/kernel may use any uart, not just uart1, depending
on the device tree configuration. They will also reset the
corresponding uarts as well. It doesn't need to be done
here.
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
This drops the dependency to riscv_internal.h which ensures
less redefinition conflicts. OpenSBI declares some of the
variables again which are spread in many NuttX files.
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
fw_start and fw_size were miscalculated. What was needed
was the pointed values of the offsets __mpfs_nuttx_start
and __mpfs_nuttx_end, not the values they had in place.
Also add the next_arg1 initialization.
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
OpenSBI may be compiled as an external library. OpenSBI commit d249d65
(Dec. 11, 2021) needs to be reverted as it causes memcpy / memcmp to
end up in the wrong section. That issue has yet no known workaround.
OpenSBI may be lauched from the hart0 (e51). It will start the U-Boot
and eventually the Linux kernel on harts 1-4.
OpenSBI, once initialized properly, will trap and handle illegal
instructions (for example, CSR time) and unaligned address accesses
among other things.
Due to size size limitations for the mpfs eNVM area where the NuttX
is located, we actually set up the OpenSBI on its own section which
is in the bottom of the DDR memory. Special care must be taken so that
the kernel doesn't override the OpenSBI. For example, the Linux device
tree may reserve some space from the beginning:
opensbi_reserved: opensbi@80000000 {
reg = <0x80000000 0x200000>;
label = "opensbi-reserved";
};
The resulting nuttx.bin file is very large, but objcopy is used to
create the final binary images for the regions (eNVM and DDR) using
the nuttx elf file.
Co-authored-by: Petro Karashchenko <petro.karashchenko@gmail.com>
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
