The branch main has been updated by mhorne:
URL:
https://cgit.FreeBSD.org/src/commit/?id=d72e944812f8774ab0b78fdff9b0204386dd6151
commit d72e944812f8774ab0b78fdff9b0204386dd6151
Author: Mitchell Horne <mho...@freebsd.org>
AuthorDate: 2020-09-11 17:02:17 +0000
Commit: Mitchell Horne <mho...@freebsd.org>
CommitDate: 2022-01-10 17:40:12 +0000
riscv: gdb(4) support
Add the MD portion required for the gdb stub.
Reviewed by: jhb (earlier version)
Discussed with: jrtc27
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D33734
---
sys/conf/files.riscv | 1 +
sys/riscv/conf/GENERIC | 2 +-
sys/riscv/conf/NOTES | 3 -
sys/riscv/include/gdb_machdep.h | 88 ++++++++++++++++++++++++++
sys/riscv/riscv/gdb_machdep.c | 135 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 225 insertions(+), 4 deletions(-)
diff --git a/sys/conf/files.riscv b/sys/conf/files.riscv
index e343b9b7f9b3..4a2d4efad137 100644
--- a/sys/conf/files.riscv
+++ b/sys/conf/files.riscv
@@ -46,6 +46,7 @@ riscv/riscv/dump_machdep.c standard
riscv/riscv/elf_machdep.c standard
riscv/riscv/exception.S standard
riscv/riscv/exec_machdep.c standard
+riscv/riscv/gdb_machdep.c optional gdb
riscv/riscv/intr_machdep.c standard
riscv/riscv/identcpu.c standard
riscv/riscv/locore.S standard no-obj
diff --git a/sys/riscv/conf/GENERIC b/sys/riscv/conf/GENERIC
index 055574920bb5..2ea0ba5c3576 100644
--- a/sys/riscv/conf/GENERIC
+++ b/sys/riscv/conf/GENERIC
@@ -173,7 +173,7 @@ options KDB # Enable kernel
debugger support.
options KDB_TRACE # Print a stack trace for a panic.
# For full debugger support use (turn off in stable branch):
options DDB # Support DDB.
-# options GDB # Support remote GDB.
+options GDB # Support remote GDB.
options DEADLKRES # Enable the deadlock resolver
options INVARIANTS # Enable calls of extra sanity checking
options INVARIANT_SUPPORT # Extra sanity checks of internal
structures, required by INVARIANTS
diff --git a/sys/riscv/conf/NOTES b/sys/riscv/conf/NOTES
index 7dda89bfe1a8..1e4b8af1840e 100644
--- a/sys/riscv/conf/NOTES
+++ b/sys/riscv/conf/NOTES
@@ -90,9 +90,6 @@ nooptions COMPAT_FREEBSD9
nooptions COMPAT_FREEBSD10
nooptions COMPAT_FREEBSD11
-# No support for remote GDB
-nooptions GDB
-
# riscv doesn't support inb/outb, so disable chipset probing which needs it
nooptions PPC_PROBE_CHIPSET
diff --git a/sys/riscv/include/gdb_machdep.h b/sys/riscv/include/gdb_machdep.h
new file mode 100644
index 000000000000..422f57a5742b
--- /dev/null
+++ b/sys/riscv/include/gdb_machdep.h
@@ -0,0 +1,88 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Mitchell Horne <mho...@freebsd.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _MACHINE_GDB_MACHDEP_H_
+#define _MACHINE_GDB_MACHDEP_H_
+
+#define GDB_BUFSZ 4096
+#define GDB_NREGS 33
+#define GDB_REG_ZERO 0
+#define GDB_REG_RA 1
+#define GDB_REG_SP 2
+#define GDB_REG_GP 3
+#define GDB_REG_TP 4
+#define GDB_REG_T0 5
+#define GDB_REG_FP 8
+#define GDB_REG_S1 9
+#define GDB_REG_A0 10
+#define GDB_REG_S2 18
+#define GDB_REG_T3 28
+#define GDB_REG_PC 32
+#define GDB_REG_CSR_BASE 65
+#define GDB_REG_SSTATUS (GDB_REG_CSR_BASE + 0x100)
+#define GDB_REG_SCAUSE (GDB_REG_CSR_BASE + 0x142)
+#define GDB_REG_STVAL (GDB_REG_CSR_BASE + 0x143)
+_Static_assert(GDB_BUFSZ >= (GDB_NREGS * 8), "buffer fits 'g' regs");
+
+static __inline size_t
+gdb_cpu_regsz(int regnum __unused)
+{
+
+ return (8);
+}
+
+static __inline int
+gdb_cpu_query(void)
+{
+ return (0);
+}
+
+static __inline void *
+gdb_begin_write(void)
+{
+
+ return (NULL);
+}
+
+static __inline void
+gdb_end_write(void *arg __unused)
+{
+
+}
+
+static __inline void
+gdb_cpu_stop_reason(int type __unused, int code __unused)
+{
+
+}
+
+void *gdb_cpu_getreg(int, size_t *);
+void gdb_cpu_setreg(int, void *);
+int gdb_cpu_signal(int, int);
+
+#endif /* !_MACHINE_GDB_MACHDEP_H_ */
diff --git a/sys/riscv/riscv/gdb_machdep.c b/sys/riscv/riscv/gdb_machdep.c
new file mode 100644
index 000000000000..06d4b8ba6e22
--- /dev/null
+++ b/sys/riscv/riscv/gdb_machdep.c
@@ -0,0 +1,135 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Mitchell Horne <mho...@freebsd.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kdb.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/signal.h>
+
+#include <machine/frame.h>
+#include <machine/gdb_machdep.h>
+#include <machine/pcb.h>
+#include <machine/riscvreg.h>
+
+#include <gdb/gdb.h>
+
+void *
+gdb_cpu_getreg(int regnum, size_t *regsz)
+{
+ *regsz = gdb_cpu_regsz(regnum);
+
+ if (kdb_thread == curthread) {
+ switch (regnum) {
+ case GDB_REG_RA: return (&kdb_frame->tf_ra);
+ case GDB_REG_PC: return (&kdb_frame->tf_sepc);
+ case GDB_REG_SSTATUS: return (&kdb_frame->tf_sstatus);
+ case GDB_REG_STVAL: return (&kdb_frame->tf_stval);
+ case GDB_REG_SCAUSE: return (&kdb_frame->tf_scause);
+ default:
+ if (regnum >= GDB_REG_A0 && regnum < GDB_REG_S2)
+ return (&kdb_frame->tf_a[regnum - GDB_REG_A0]);
+ if (regnum >= GDB_REG_T0 && regnum < GDB_REG_FP)
+ return (&kdb_frame->tf_t[regnum - GDB_REG_T0]);
+ if (regnum >= GDB_REG_T3 && regnum < GDB_REG_PC)
+ return (&kdb_frame->tf_t[regnum - GDB_REG_T3]);
+ break;
+ }
+ }
+ switch (regnum) {
+ case GDB_REG_PC: /* FALLTHROUGH */
+ case GDB_REG_RA: return (&kdb_thrctx->pcb_ra);
+ case GDB_REG_SP: return (&kdb_thrctx->pcb_sp);
+ case GDB_REG_GP: return (&kdb_thrctx->pcb_gp);
+ case GDB_REG_TP: return (&kdb_thrctx->pcb_tp);
+ case GDB_REG_FP: return (&kdb_thrctx->pcb_s[0]);
+ case GDB_REG_S1: return (&kdb_thrctx->pcb_s[1]);
+ default:
+ if (regnum >= GDB_REG_S2 && regnum < GDB_REG_T3)
+ return (&kdb_thrctx->pcb_s[regnum - GDB_REG_S2]);
+ break;
+ }
+
+ return (NULL);
+}
+
+void
+gdb_cpu_setreg(int regnum, void *val)
+{
+ register_t regval = *(register_t *)val;
+
+ /* For curthread, keep the pcb and trapframe in sync. */
+ if (kdb_thread == curthread) {
+ switch (regnum) {
+ case GDB_REG_PC: kdb_frame->tf_sepc = regval; break;
+ case GDB_REG_RA: kdb_frame->tf_ra = regval; break;
+ case GDB_REG_SP: kdb_frame->tf_sp = regval; break;
+ case GDB_REG_GP: kdb_frame->tf_gp = regval; break;
+ case GDB_REG_TP: kdb_frame->tf_tp = regval; break;
+ case GDB_REG_FP: kdb_frame->tf_s[0] = regval; break;
+ case GDB_REG_S1: kdb_frame->tf_s[1] = regval; break;
+ case GDB_REG_SSTATUS: kdb_frame->tf_sstatus = regval; break;
+ case GDB_REG_STVAL: kdb_frame->tf_stval = regval; break;
+ case GDB_REG_SCAUSE: kdb_frame->tf_scause = regval; break;
+ default:
+ if (regnum >= GDB_REG_A0 && regnum < GDB_REG_S2)
+ kdb_frame->tf_a[regnum - GDB_REG_A0] = regval;
+ if (regnum >= GDB_REG_S2 && regnum < GDB_REG_T3)
+ kdb_frame->tf_s[regnum - GDB_REG_S2] = regval;
+ if (regnum >= GDB_REG_T0 && regnum < GDB_REG_FP)
+ kdb_frame->tf_t[regnum - GDB_REG_T0] = regval;
+ if (regnum >= GDB_REG_T3 && regnum < GDB_REG_PC)
+ kdb_frame->tf_t[regnum - GDB_REG_T3] = regval;
+ break;
+ }
+ }
+ switch (regnum) {
+ case GDB_REG_PC: /* FALLTHROUGH */
+ case GDB_REG_RA: kdb_thrctx->pcb_ra = regval; break;
+ case GDB_REG_SP: kdb_thrctx->pcb_sp = regval; break;
+ case GDB_REG_GP: kdb_thrctx->pcb_gp = regval; break;
+ case GDB_REG_TP: kdb_thrctx->pcb_tp = regval; break;
+ case GDB_REG_FP: kdb_thrctx->pcb_s[0] = regval; break;
+ case GDB_REG_S1: kdb_thrctx->pcb_s[1] = regval; break;
+ default:
+ if (regnum >= GDB_REG_S2 && regnum < GDB_REG_T3)
+ kdb_thrctx->pcb_s[regnum - GDB_REG_S2] = regval;
+ break;
+ }
+}
+
+int
+gdb_cpu_signal(int type, int code)
+{
+
+ if (type == SCAUSE_BREAKPOINT)
+ return (SIGTRAP);
+
+ return (SIGEMT);
+}
