docs/devel/kconfig.rst

11 card, even though the boards use different PCI host bridges, and they
13 SCSI adapters.  Arm, s390 and x86 boards can all present a virtio-blk
21 QEMU uses a simple domain-specific language to describe the dependencies
36 This domain-specific language is based on the Kconfig language that
41 is instead specified in per-target files under the ``configs/``
48 --------------------
59       config ARM_VIRT
68 The ``config`` keyword introduces a new configuration element.  In the example
78 include it for clarity and future-proofing.  After ``bool`` the following
93     config FOO
105   Default values are assigned to the config symbol if no other value was
125     config FOO
129     config BAZ
136 ------------------------------------
145     config SCSI
160     config MEGASAS_SCSI_PCI
186     config PCI_DEVICES
199   for example only VFIO (passthrough) and virtio-pci devices.
202   board (and not ones which are very board-specific or that need
212     config SUN4M
248     config ECCMEMCTL
258 --------------------------------------------
261 a file called ``configs/TARGETNAME-softmmu.mak``.  These files
262 initialize some Kconfig variables to non-default values and provide the
267     # Default configuration for alpha-softmmu
278 The first part, consisting of commented-out ``=n`` assignments, tells
286 ``--without-default-devices`` option.  When this is done, everything defaults
298 machine, and even then only if ``--nodefaults`` is specified on the
299 command line.  Starting a VM *without* ``--nodefaults`` is allowed to
301 ``--without-default-devices`` are considered bugs in the test code:
302 the tests should either use ``--nodefaults``, and should be skipped
311 ``Kconfig.host``
312 ----------------
314 In some special cases, a configurable element depends on host features
317 of a library on the host.
319 These symbols should be listed in ``Kconfig.host`` like this::
321     config TPM
324 and also listed as follows in the top-level meson.build's host_kconfig