Thomas Huth <th...@redhat.com> writes: > On 25.04.2018 17:33, Alex Bennée wrote: >> People following old instructions for QEMU get the message "No machine >> specified, and there is no default" and run -machine help to pick a >> new machine. Lay people might consider the null-machine to be such a >> basic starting point but they won't get far. This leads to confusion, >> see https://bugs.launchpad.net/qemu/+bug/1766896 as an example. >> >> I'm open to better words - I figured "THIS PROBABLY ISN'T WHAT YOU >> WANT" seemed less helpful though. >> >> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> >> --- >> hw/core/null-machine.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c >> index cde4d3eb57..72f0815045 100644 >> --- a/hw/core/null-machine.c >> +++ b/hw/core/null-machine.c >> @@ -50,7 +50,7 @@ static void machine_none_init(MachineState *mch) >> >> static void machine_none_machine_init(MachineClass *mc) >> { >> - mc->desc = "empty machine"; >> + mc->desc = "empty machine (for probing/QMP)"; > > Actually, with certain CPUs, you can really use the "none" machine as a > pure instruction set testing system. For example, on m68k, there used to > be an explicit "dummy" machine for this job, and we removed it in favour > of the "none" machine: > > https://git.qemu.org/?p=qemu.git;a=commitdiff;h=22f2dbe7eaf3e12e38c9c210
Ahh OK. Do you know what other CPUs can be used in this way? > So I'd rather not add such wording. We should rather fix those segfaults > instead (QEMU should never segfault - in case a device can not be used > with the "none" machine, there rather should be an error message instead). Hmm the ARM world is complicated by peripherals that are on-chip but not part of the "CPU". I wonder if this is a edge case for our modelling? Should for example -cpu cortex-m3 imply additional peripherals and how do we handle that in the -m none case? -- Alex Bennée
