(the value we had before supervisor exception occurred).
This helps consumers (e.g. DTrace) to not proceed additional calculations.
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
memory system.
RISC-V ISA has only single page table base register for both kernel
and user addresses translation. Before this commit we were using an
extra (4th) level of pagetables for switching between kernel and user
pagetables, but then realized FPGA hardware has 3-level page system
hardcoded. It is also become clear that the bitfile synthesized for
4-level system is untested/broken, so we can't use extra level for
switching.
We are now share level 1 of pagetables between kernel and user VA.
This requires to keep track of all the user pmaps created and once we
adding L1 page to kernel pmap we have to add it to all the user pmaps.
o Change the VM layout as we must have topmost bit to be 1 in the
selected page system for kernel addresses and 0 for user addresses.
o Implement pmap_kenter_device().
o Create the l3 tables for the early devmap.
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Sounds strange, but both RocketCore and lowRISC do not operate
if we set it.
All the known implementations (Spike, QEMU, RocketCore, lowRISC) uses
default machine trap vector address and operates fine with this.
Original Berkeley Boot Loader (bbl) does not set this as well.
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
There is no need to clear all the DDR memory (we only need to clear
BSS section).
I was playing with non-default version of hardware (the bitfile
synthesized for 4-level page memory system) and clearing was helpful,
but then realized support for 4-level page system is untested/broken
in both RocketCore and lowRISC.
Summary:
As part of the migration of rman_res_t to be typed to uintmax_t, memory ranges
must be clamped appropriately for the bus, to prevent completely bogus addresses
from being used.
This is extracted from D4544.
Reviewed By: cem
Sponsored by: Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5134
Use u_long instead of uint32_t variables to avoid overflow
in case of PA space bigger than 32-bit.
Obtained from: Semihalf
Submitted by: Michal Stanek <mst@semihalf.com>
Sponsored by: Annapurna Labs
Approved by: cognet (mentor)
Reviewed by: andrew, br, wma
Differential revision: https://reviews.freebsd.org/D5393
o Implement growkernel bits for L1 level of pagetables.
This allows us to boot with 128GB of physical memory.
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Tested on Spike simulator with 2 and 16 cores (tlb enabled),
so set MAXCPU to 16 at this time.
This uses FDT data to get information about CPUs
(code based on arm64 mp_machdep).
Invalidate entire TLB cache as it is the only way yet.
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
need to include it explicitly when <vm/vm_param.h> is already included.
Suggested by: alc
Reviewed by: alc
Differential Revision: https://reviews.freebsd.org/D5379
This simplifies checking for default resource range for bus_alloc_resource(),
and improves readability.
This is part of, and related to, the migration of rman_res_t from u_long to
uintmax_t.
Discussed with: jhb
Suggested by: marcel
o Add kernel configuration for QEMU.
Both SPIKE and QEMU kernel configs are temporary (until
we will be able to obtain DTB from loader).
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
This fixes operation in QEMU and saves some booting time as well.
Pointed out by: Sagar Karandikar <skarandikar@berkeley.edu>
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
gp (global pointer) is used by compiler in userland only,
so re-use it for pcpup in kernel, save it on stack on switching
out to userland and load back on return to kernel.
Discussed with: jhb, andrew, kib
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D5178
This is the final step required allowing to compile and to run RISC-V
kernel and userland from HEAD.
RISC-V is a completely open ISA that is freely available to academia
and industry.
Thanks to all the people involved! Special thanks to Andrew Turner,
David Chisnall, Ed Maste, Konstantin Belousov, John Baldwin and
Arun Thomas for their help.
Thanks to Robert Watson for organizing this project.
This project sponsored by UK Higher Education Innovation Fund (HEIF5) and
DARPA CTSRD project at the University of Cambridge Computer Laboratory.
FreeBSD/RISC-V project home: https://wiki.freebsd.org/riscv
Reviewed by: andrew, emaste, kib
Relnotes: Yes
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D4982
