Am 13.08.2013 12:05, schrieb James Hogan: > On 12 August 2013 20:44, Aurelien Jarno <aurel...@aurel32.net> wrote: >> Since commit c658b94f6e8c206c59d02aa6fbac285b86b53d2c, MIPS raises >> exceptions when accessing invalid memory. This is not the correct >> behaviour for MIPS Malta Core LV, as the GT-64120A system controller >> just ignore undecoded access. This feature is used by the Linux kernel >> to probe for some devices. >> >> Emulate the correct behaviour in QEMU by adding an empty slot covering >> the entire memory space decoded by the GT-64120A. >> >> Signed-off-by: Aurelien Jarno <aurel...@aurel32.net> >> --- > > <snip> > >> @@ -908,6 +909,11 @@ void mips_malta_init(QEMUMachineInitArgs *args) >> DeviceState *dev = qdev_create(NULL, TYPE_MIPS_MALTA); >> MaltaState *s = MIPS_MALTA(dev); >> >> + /* The whole address space decoded by the GT-64120A doesn't generate >> + exception when accessing invalid memory. Create an empty slot to >> + emulate this feature. */ >> + empty_slot_init(0, 0x1fffffff); > > Out of interest, any particular reason not to put this in > hw/mips/gt64xxx_pci.c? As far as I can tell from your description it's > specific to the GT-64* system controller rather than the malta board?
I was assuming that we didn't properly model that device when putting it on the board directly, but if there is one then putting it into such a device will avoid having to copy it into multiple boards. Perhaps in that case we can even have a proper MemoryRegion in the SysBus device instead of a separate empty slot pseudo-device? FWIW gt64xxx_pci.c could certainly use some more love to eliminate gt64120_register() and to create PCIDevice and PCIBus in the bridge itself for instance... Regards, Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
