On 18.01.2017 18:57, Alistair Francis wrote: > On Wed, Jan 18, 2017 at 4:44 AM, Thomas Huth <th...@redhat.com> wrote: >> Sometimes it is useful to have just a machine with CPU and RAM, without >> any further hardware in it, e.g. if you just want to do some instruction >> debugging for TCG with a remote GDB attached to QEMU, or run some embedded >> code with the "-semihosting" QEMU parameter. qemu-system-m68k already >> features a "dummy" machine, and xtensa a "sim" machine for exactly this >> purpose. >> All target architectures have nowadays also a "none" machine, which would >> be a perfect match for this, too - but it currently does not allow to add >> CPU and RAM yet. Thus let's add these possibilities in a generic way to the >> "none" machine, too, so that we hopefully do not need additional "dummy" >> machines in the future anymore (and maybe can also get rid of the already >> existing "dummy"/"sim" machines one day). >> Note that the default behaviour of the "none" machine is not changed, i.e. >> no CPU and no RAM is instantiated by default. You have explicitely got to >> specify the CPU model with "-cpu" and the amount of RAM with "-m" to get >> these new features. >> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> v3: >> - Get rid of the cpu_init_def() wrapper again, make null-machine.o >> target dependent instead and use cpu_init() directly. >> - Omit the loader code for the "-kernel" option for now (users can >> use "-device loader,..." instead). We can add code for the -kernel >> parameter later (either an implementation or a warning), once we've >> decided how it should behave for the "none" machine. > > I think there should at least be a warning to start with though. It > seems confusing that no errors are reported but the argument is > ignored.
I'm still rather in favor of adding the hunk here that calls the generic loader for "-kernel" ... anyway, we can add either behavior with a later patch. So far the "none" machine never reported an error here, so this is not a regression if we do not have this right from the start. Thomas
