arm64: gdb(4) machine-dependent bits

Everything required for remote kernel debugging over a serial
connection. For FDT-based systems, a debug port can be specified by
setting hw.fdt.dbgport to the desired device tree node in loader.conf.
For example, hw.fdt.dbgport="uart1", or
hw.fdt.dbgport="serial@ff1a0000".

Looks good:	emaste
Tested by:	rwatson
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D27727
This commit is contained in:
mhorne 2020-12-09 16:38:42 -04:00 committed by Mitchell Horne
parent 5f66d5a313
commit bbfa199cbc
4 changed files with 195 additions and 1 deletions

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@ -0,0 +1,112 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 The FreeBSD Foundation
*
* This software was developed by Mitchell Horne under sponsorship from
* the FreeBSD Foundation.
*
* 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/armreg.h>
#include <machine/frame.h>
#include <machine/gdb_machdep.h>
#include <machine/pcb.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_LR: return (&kdb_frame->tf_lr);
case GDB_REG_SP: return (&kdb_frame->tf_sp);
case GDB_REG_PC: return (&kdb_frame->tf_elr);
case GDB_REG_CSPR: return (&kdb_frame->tf_spsr);
}
}
switch (regnum) {
case GDB_REG_SP: return (&kdb_thrctx->pcb_sp);
case GDB_REG_PC: /* FALLTHROUGH */
case GDB_REG_LR: return (&kdb_thrctx->pcb_lr);
default:
if (regnum >= GDB_REG_X0 && regnum <= GDB_REG_X29)
return (&kdb_thrctx->pcb_x[regnum]);
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_elr = regval; break;
case GDB_REG_SP: kdb_frame->tf_sp = regval; break;
default:
if (regnum >= GDB_REG_X0 && regnum <= GDB_REG_X29) {
kdb_frame->tf_x[regnum] = regval;
}
break;
}
}
switch (regnum) {
case GDB_REG_PC: /* FALLTHROUGH */
case GDB_REG_LR: kdb_thrctx->pcb_lr = regval; break;
case GDB_REG_SP: kdb_thrctx->pcb_sp = regval; break;
default:
if (regnum >= GDB_REG_X0 && regnum <= GDB_REG_X29) {
kdb_thrctx->pcb_x[regnum] = regval;
}
break;
}
}
int
gdb_cpu_signal(int type, int code __unused)
{
switch (type) {
case EXCP_WATCHPT_EL1:
case EXCP_SOFTSTP_EL1:
case EXCP_BRK:
return (SIGTRAP);
}
return (SIGEMT);
}

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@ -87,7 +87,7 @@ 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

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@ -0,0 +1,81 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 The FreeBSD Foundation
*
* This software was developed by Mitchell Horne under sponsorship from
* the FreeBSD Foundation.
*
* 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 68
#define GDB_REG_X0 0
#define GDB_REG_X29 29
#define GDB_REG_LR 30
#define GDB_REG_SP 31
#define GDB_REG_PC 32
#define GDB_REG_CSPR 33
#define GDB_REG_V0 34
#define GDB_REG_V31 65
#define GDB_REG_FPSR 66
#define GDB_REG_FPCR 67
_Static_assert(GDB_BUFSZ >= (GDB_NREGS * 16), "buffer fits 'g' regs");
static __inline size_t
gdb_cpu_regsz(int regnum)
{
if (regnum == GDB_REG_CSPR || regnum == GDB_REG_FPSR ||
regnum == GDB_REG_FPCR)
return (4);
else if (regnum >= GDB_REG_V0 && regnum <= GDB_REG_V31)
return (16);
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)
{
}
void *gdb_cpu_getreg(int, size_t *);
void gdb_cpu_setreg(int, void *);
int gdb_cpu_signal(int, int);
#endif /* !_MACHINE_GDB_MACHDEP_H_ */

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@ -168,6 +168,7 @@ arm64/arm64/elf32_machdep.c optional compat_freebsd32
arm64/arm64/elf_machdep.c standard
arm64/arm64/exception.S standard
arm64/arm64/freebsd32_machdep.c optional compat_freebsd32
arm64/arm64/gdb_machdep.c optional gdb
arm64/arm64/gicv3_its.c optional intrng fdt
arm64/arm64/gic_v3.c standard
arm64/arm64/gic_v3_acpi.c optional acpi