NOTE: THIS ONLY WORKS WHEN KERNEL RUNS IN M-MODE FOR NOW
This frees the PMP for other use, e.g. HART memory separation.
The page tables are statically allocated, 1 per level.
This feature is now behind CONFIG_MPFS_USE_MMU_AS_MPU, because
only the MPFS target supports this (others are not tested).
If the MMU is used for memory separation within a HART, the PMP must
still be configured to allow user access to the memory mapped for the
HART, because PMP *rekoves* access by default. At this point all of
the user memory as well as the kernel RAM are opened.
A more flexible solution for PMP configuration will follow.
The old implementation used the default ld.script for the kernel side
which did not obey the memory.ld limits whatsoever.
Also, provide the user space addresses from the linker script to get rid
of the pre-processor macros that define (incorrect) default values for
the user space composition.
Some of the configuration options have changed, so update this
config file accordingly.
In this example config, the following hart configuration takes
place:
hart1: 0xafb00000 (Another NuttX)
hart2: unused
hart3: 0x80200000 (u-boot and Linux kernel)
hart4: 0x80200000 (u-boot and Linux kernel)
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
RAM is expected to start from 0x08000000, not from
0x80000000 in this case. DDR starts from 0x80000000.
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
Add a pinmap header for mpfs to be able to configure MSSIO GPIOs
This also adds Kconfigs for some different chip/package types of the PolarFire SOC
Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
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>
