Running the WDR opcode triggers a segfault:
$ cat > foo.S << EOF
> __start:
> wdr
> EOF
$ avr-gcc -nostdlib -nostartfiles -mmcu=avr6 foo.S -o foo.elf
$ qemu-system-avr -serial mon:stdio -nographic -no-reboot \
-M mega -bios foo.elf -d in_asm --singlestep
IN:
0x00000000: WDR
Segmentation fault (core dumped)
(gdb) bt
#0 0x00005555add0b23a in gdb_get_cpu_pid (cpu=0x5555af5a4af0) at
../gdbstub.c:718
#1 0x00005555add0b2dd in gdb_get_cpu_process (cpu=0x5555af5a4af0) at
../gdbstub.c:743
#2 0x00005555add0e477 in gdb_set_stop_cpu (cpu=0x5555af5a4af0) at
../gdbstub.c:2742
#3 0x00005555adc99b96 in cpu_handle_guest_debug (cpu=0x5555af5a4af0) at
../softmmu/cpus.c:306
#4 0x00005555adcc66ab in rr_cpu_thread_fn (arg=0x5555af5a4af0) at
../accel/tcg/tcg-accel-ops-rr.c:224
#5 0x00005555adefaf12 in qemu_thread_start (args=0x5555af5d9870) at
../util/qemu-thread-posix.c:521
#6 0x00007f692d940ea5 in start_thread () from /lib64/libpthread.so.0
#7 0x00007f692d6699fd in clone () from /lib64/libc.so.6
Since the watchdog peripheral is not implemented, simply
log the opcode as unimplemented and keep going.
Reported-by: Fred Konrad <konrad@adacore.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
target/avr/helper.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/target/avr/helper.c b/target/avr/helper.c
index 35e10195940..981c29da453 100644
--- a/target/avr/helper.c
+++ b/target/avr/helper.c
@@ -188,11 +188,7 @@ void helper_break(CPUAVRState *env)
void helper_wdr(CPUAVRState *env)
{
- CPUState *cs = env_cpu(env);
-
- /* WD is not implemented yet, placeholder */
- cs->exception_index = EXCP_DEBUG;
- cpu_loop_exit(cs);
+ qemu_log_mask(LOG_UNIMP, "WDG reset (not implemented)\n");
}