This patchset implements the m68k "any instruction" tracing mode which is used
by the NetBSD kernel debugger to implement single-stepping. It is based upon
reading through the M68000 PRM and looking at how the ARM target handles both
gdbstub and architectural single-step exceptions.
With this patchset it becomes possible to single-step the NetBSD kernel using
the in-built kernel debugger:
Stopped in pid 0.1 (system) at netbsd:cpu_Debugger+0x6: unlk a6
db> s
Stopped in pid 0.1 (system) at netbsd:cpu_Debugger+0x8: rts
db>
Stopped in pid 0.1 (system) at netbsd:main+0x2c: jsr kernel_lock_init
[addr:0x1a38f6 ]
db>
Stopped in pid 0.1 (system) at netbsd:kernel_lock_init: linkw a6,#0
db>
Stopped in pid 0.1 (system) at netbsd:kernel_lock_init+0x4: clrb kernel_l
ock [addr:0x33f400 ]
db>
Stopped in pid 0.1 (system) at netbsd:kernel_lock_init+0xa: clrb kernel_l
ock_dodebug [addr:0x35b48c ]
db>
Stopped in pid 0.1 (system) at netbsd:kernel_lock_init+0x10: unlk a6
db>
Stopped in pid 0.1 (system) at netbsd:kernel_lock_init+0x12: rts
db> c
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
[ 1.0000000] 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015,
2016, 2017,
[ 1.0000000] 2018, 2019, 2020 The NetBSD Foundation, Inc. All rights
reserved.
[ 1.0000000] Copyright (c) 1982, 1986, 1989, 1991, 1993
[ 1.0000000] The Regents of the University of California. All rights
reserved.
[ 1.0000000] NetBSD 9.1 (GENERIC) #0: Sun Oct 18 19:24:30 UTC 2020
... etc ...
Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
[q800-macos-upstream patchset series: 2]
Mark Cave-Ayland (4):
target/m68k: introduce is_singlestepping() function
target/m68k: call gen_raise_exception() directly if single-stepping in
gen_jmp_tb()
target/m68k: introduce gen_singlestep_exception() function
target/m68k: implement m68k "any instruction" trace mode
target/m68k/cpu.h | 8 +++++++
target/m68k/translate.c | 51 ++++++++++++++++++++++++++++++++++-------
2 files changed, 51 insertions(+), 8 deletions(-)
--
2.20.1
