The existing names were inherited from arm64, but we should prefer
RISC-V terminology. Change the prefix to SCAUSE, and further change the
names to better match the RISC-V spec and be more consistent with one
another. Also, remove two codes that are not defined for S-mode (machine
and hypervisor ecall).
While here, apply style(9) to some condition checks.
Reviewed by: kp
Discussed with: jrtc27
Differential Revision: https://reviews.freebsd.org/D26918
While cause codes higher than 16 are reserved, the exception code
field of the register is defined to be all bits but the upper-most
bit.
Reviewed by: mhorne
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23510
The SD bit is defined as the MSB of the sstatus register, meaning its
position will vary depending on the CSR's length. Previously, there were
two (unused) defines for this, for the 32 and 64-bit cases, but their
definitions were swapped.
Consolidate these into one define: SSTATUS_SD, and make the definition
dependent on the value of __riscv_xlen.
Reviewed by: br
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D23402
The existing copyin(9) and copyout(9) routines on RISC-V perform only a
simple byte-by-byte copy. Improve their performance by performing
word-sized copies where possible.
Submitted by: Mitchell Horne <mhorne063@gmail.com>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18851
The RISC-V spec defines several performance counter CSRs such as: cycle,
time, instret, hpmcounter(3...31). They are defined to be 64-bits wide
on all RISC-V architectures. On RV64 and RV128 they can be read from a
single CSR. On RV32, additional CSRs (given the suffix "h") are present
which contain the upper 32 bits of these counters, and must be read as
well. (See section 2.8 in the User ISA Spec for full details.)
This change adds macros for reading these values safely on any RISC-V
ISA length. Obviously we aren't supporting anything other than RV64
at the moment, but this ensures we won't need to change how we read
these values if we ever do.
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: jhb
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D17952
New version is not compatible on supervisor mode with v1.9.1
(previous version).
Highlights:
o BBL (Berkeley Boot Loader) provides no initial page tables
anymore allowing us to choose VM, to build page tables manually
and enable MMU in S-mode.
o SBI interface changed.
o GENERIC kernel.
FDT is now chosen standard for RISC-V hardware description.
DTB is now provided by Spike (golden model simulator). This
allows us to introduce GENERIC kernel. However, description
for console and timer devices is not provided in DTB, so move
these devices temporary to nexus bus.
o Supervisor can't access userspace by default. Solution is to
set SUM (permit Supervisor User Memory access) bit in sstatus
register.
o Compressed extension is now turned on by default.
o External GCC 7.1 compiler used.
o _gp renamed to __global_pointer$
o Compiler -march= string is now in use allowing us to choose
required extensions (compressed, FPU, atomic, etc).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11800
Hardfloat is now default (use riscv64sf as TARGET_ARCH
for softfloat).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D8529
Machine privilege level was specially designed to use in vendor's
firmware or bootloader. We have implemented operation in machine
mode in FreeBSD as part of understanding RISC-V ISA, but it is time
to remove it.
We now use BBL (Berkeley Boot Loader) -- standard RISC-V firmware,
which provides operation in machine mode for us.
We now use standard SBI calls to machine mode, instead of handmade
'syscalls'.
o Remove HTIF bus.
HTIF bus is now legacy and no longer exists in RISC-V specification.
HTIF code still exists in Spike simulator, but BBL do not provide
raw interface to it.
Memory disk is only choice for now to have multiuser booted in Spike,
until Spike has implemented more devices (e.g. Virtio, etc).
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
