docs/devel/reset.rst

21 to control it. All resettable control functions must be called while holding
26 instantly reset an object, without keeping it in reset state, just call
33   Cold reset is supported by every resettable object. In QEMU, it means we reset
35   from what is a real hardware cold reset. It differs from other resets (like
59   This is only used for S390 CPU objects; it clears interrupts, stops
63   This is only used for S390 CPU objects; it does everything
65   FPC, timer and control registers. It does not touch gprs, fprs or acrs.
72 ``resettable_assert_reset()`` then ``resettable_release_reset()``. It is
78 maintaining a count of in-progress resets; it is crucial to call
87 parameter. Still, it is a programming error to call a resettable function on a
88 non-resettable object and it will trigger a run time assert error. Since most
102 between resetting a bus and resetting the controller bridge which owns it.
106 it but not the controller.
124 1. The **enter** phase is executed when the object enters reset. It resets only
125    local state of the object; it must not do anything that has a side-effect
143 the object does not need to care how many of reset controllers it has and how
156 must provide and what functions it has access to. It is intended for people
230 In the above example, we override all three phases. It is possible to override
256 it will probably need to ignore it while in reset; then it can for
273 about if you are extending it to work with a new base class other than
275 people can ignore it.
286 The structure must be allocated by the base class; preferably it should be
289 ``child_foreach()`` is more complex. It should execute the given callback on
296 to follow the bus hierarchy; for a bus, it calls the function on every child
297 device; for a device, it calls the function on every bus child. When we reset
310 parameters, it takes the object being moved, the old parent if any and the new
314 a reset operation it must be used only in *hold* phase. Using it in *enter* or
316 Also it should not be used during machine creation, although it is harmless to
322 1. *device hotplug*; it means a new device is introduced on a live bus.
324 2. *hot bus change*; it means an existing live device is added, moved or
325    removed in the bus hierarchy. At the moment, it occurs only in the raspi
344    the current machine, if it has one. That method must call
349    the three-phase mechanism listed above. It resets all objects
350    that were registered with it using ``qemu_register_resettable()``.
351    It also calls all the functions registered with it using