Commit Graph

8 Commits (aa464db69b40b4b695be31085e6d2f1e90956c89)

Author SHA1 Message Date
Jonathan Behrens 81d2929c41
target/riscv: Make the priv register writable by GDB
Currently only PRV_U, PRV_S and PRV_M are supported, so this patch ensures that
the privilege mode is set to one of them. Once support for the H-extension is
added, this code will also need to properly update the virtualization status
when switching between VU/VS-modes and M-mode.

Signed-off-by: Jonathan Behrens <jonathan@fintelia.io>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-10-28 07:47:29 -07:00
Jonathan Behrens ab9056ff9b
target/riscv: Expose "priv" register for GDB for reads
This patch enables a debugger to read the current privilege level via a virtual
"priv" register. When compiled with CONFIG_USER_ONLY the register is still
visible but always reports the value zero.

Signed-off-by: Jonathan Behrens <jonathan@fintelia.io>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-10-28 07:47:29 -07:00
Jonathan Behrens a555ad1399
target/riscv: Tell gdbstub the correct number of CSRs
If the number of registers reported to the gdbstub code does not match the
number in the associated XML file, then the register numbers used by the stub
may get out of sync with a remote GDB instance.

Signed-off-by: Jonathan Behrens <jonathan@fintelia.io>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-10-28 07:47:28 -07:00
KONRAD Frederic b3e8692918
gdbstub: riscv: fix the fflags registers
While debugging an application with GDB the following might happen:

(gdb) return
Make xxx return now? (y or n) y
Could not fetch register "fflags"; remote failure reply 'E14'

This is because riscv_gdb_get_fpu calls riscv_csrrw_debug with a wrong csr
number (8). It should use the csr_register_map in order to reach the
riscv_cpu_get_fflags callback.

Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-09-17 08:42:50 -07:00
Markus Armbruster a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Jim Wilson 5371f5cd71
RISC-V: Add hooks to use the gdb xml files.
The gdb CSR xml file has registers in documentation order, not numerical
order, so we need a table to map the register numbers.  This also adds
fairly standard gdb hooks to access xml specified registers.

notice:
    The fpu xml from gdb 8.3 has unused register #, 65 and make first
    csr register # become 69. We register extra register on gdb to correct
    csr offset calculation

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19 05:13:24 -07:00
Michael Clark c7b9517188
RISC-V: Implement modular CSR helper interface
Previous CSR code uses csr_read_helper and csr_write_helper
to update CSR registers however this interface prevents
atomic read/modify/write CSR operations; in addition
there is no trap-free method to access to CSRs due
to the monolithic CSR functions call longjmp.

The current iCSR interface is not safe to be called by
target/riscv/gdbstub.c as privilege checks or missing CSRs
may call longjmp to generate exceptions. It needs to
indicate existence so traps can be generated in the
CSR instruction helpers.

This commit moves CSR access from the monolithic switch
statements in target/riscv/op_helper.c into modular
read/write functions in target/riscv/csr.c using a new
function pointer table for dispatch (which can later
be used to allow CPUs to hook up model specific CSRs).

A read/modify/write interface is added to support atomic
CSR operations and a non-trapping interface is added
to allow exception-free access to CSRs by the debugger.

The CSR functions and CSR dispatch table are ordered
to match The RISC-V Instruction Set Manual, Volume II:
Privileged Architecture Version 1.10, 2.2 CSR Listing.

An API is added to allow derived cpu instances to modify
or implement new CSR operations.

Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-08 13:59:09 -08:00
Michael Clark 9438fe7d7c
RISC-V GDB Stub
GDB Register read and write routines.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Sagar Karandikar <sagark@eecs.berkeley.edu>
Signed-off-by: Michael Clark <mjc@sifive.com>
2018-03-07 08:30:28 +13:00