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1.. _platform:
2
3Platform
4========
5
6:class:`Platform`\ s describe the system underlying the OS. They encapsulate
7hardware- and firmware-specific details. In most cases, the generic
8:class:`Platform` class, which gets used if a platform is not explicitly
9specified on :class:`Target` creation, will be sufficient. It will automatically
10query as much platform information (such CPU topology, hardware model, etc) if
11it was not specified explicitly by the user.
12
13
14.. class:: Platform(name=None, core_names=None, core_clusters=None,\
15                    big_core=None, model=None, modules=None)
16
17    :param name: A user-friendly identifier for the platform.
18    :param core_names: A list of CPU core names in the order they appear
19                       registered with the OS. If they are not specified,
20                       they will be queried at run time.
21    :param core_clusters: Alist with cluster ids of each core (starting with
22                          0). If this is not specified, clusters will be
23                          inferred from core names (cores with the same name are
24                          assumed to be in a cluster).
25    :param big_core: The name of the big core in a big.LITTLE system. If this is
26                     not specified it will be inferred (on systems with exactly
27                     two clasters).
28    :param model: Model name of the hardware system. If this is not specified it
29                  will be queried at run time.
30    :param modules: Modules with additional functionality supported by the
31                    platfrom (e.g. for handling flashing, rebooting, etc). These
32                    would be added to the Target's modules. (See :ref:`modules`\ ).
33
34
35Versatile Express
36-----------------
37
38The generic platform may be extended to support hardware- or
39infrastructure-specific functionality. Platforms exist for ARM
40VersatileExpress-based :class:`Juno` and :class:`TC2` development boards. In
41addition to the standard :class:`Platform` parameters above, these platfroms
42support additional configuration:
43
44
45.. class:: VersatileExpressPlatform
46
47    Normally, this would be instatiated via one of its derived classes
48    (:class:`Juno` or :class:`TC2`) that set appropriate defaults for some of
49    the parameters.
50
51    :param serial_port: Identifies the serial port (usual a /dev node) on which the
52                        device is connected.
53    :param baudrate: Baud rate for the serial connection. This defaults to
54                     ``115200`` for :class:`Juno` and ``38400`` for
55                     :class:`TC2`.
56    :param vemsd_mount: Mount point for the VEMSD (Versatile Express MicroSD card
57                        that is used for board configuration files and firmware
58                        images). This defaults to ``"/media/JUNO"`` for
59                        :class:`Juno` and ``"/media/VEMSD"`` for :class:`TC2`,
60                        though you would most likely need to change this for
61                        your setup as it would depend both on the file system
62                        label on the MicroSD card, and on how the card was
63                        mounted on the host system.
64    :param hard_reset_method: Specifies the method for hard-resetting the devices
65                            (e.g. if it becomes unresponsive and normal reboot
66                            method doesn not work). Currently supported methods
67                            are:
68
69                            :dtr: reboot by toggling DTR line on the serial
70                                  connection (this is enabled via a DIP switch
71                                  on the board).
72                            :reboottxt: reboot by writing a filed called
73                                        ``reboot.txt`` to the root of the VEMSD
74                                        mount (this is enabled via board
75                                        configuration file).
76
77                            This defaults to ``dtr`` for :class:`Juno` and
78                            ``reboottxt`` for :class:`TC2`.
79    :param bootloader: Specifies the bootloader configuration used by the board.
80                      The following values are currently supported:
81
82                       :uefi: Boot via UEFI menu, by selecting the entry
83                              specified by ``uefi_entry`` paramter. If this
84                              entry does not exist, it will be automatically
85                              created based on values provided for ``image``,
86                              ``initrd``, ``fdt``, and ``bootargs`` parameters.
87                       :uefi-shell: Boot by going via the UEFI shell.
88                       :u-boot: Boot using Das U-Boot.
89                       :bootmon: Boot directly via Versatile Express Bootmon
90                                 using the values provided for ``image``,
91                                 ``initrd``, ``fdt``, and ``bootargs``
92                                 parameters.
93
94                      This defaults to ``u-boot`` for :class:`Juno` and
95                      ``bootmon`` for :class:`TC2`.
96    :param flash_method: Specifies how the device is flashed. Currently, only
97                        ``"vemsd"`` method is supported, which flashes by
98                        writing firmware images to an appropriate location on
99                        the VEMSD.
100    :param image: Specfies the kernel image name for ``uefi``  or ``bootmon`` boot.
101    :param fdt: Specifies the device tree blob for  ``uefi``  or ``bootmon`` boot.
102    :param initrd: Specifies the ramdisk image for  ``uefi`` or ``bootmon`` boot.
103    :param bootargs: Specifies the boot arguments that will be pass to the
104                     kernel by the bootloader.
105    :param uefi_entry: Then name of the UEFI entry to be used/created by
106                       ``uefi`` bootloader.
107    :param ready_timeout: Timeout, in seconds, for the time it takes the
108                          platform to become ready to accept connections. Note:
109                          this does not mean that the system is fully booted;
110                          just that the services needed to establish a
111                          connection (e.g. sshd or adbd) are up.
112
113
114.. _gem5-platform:
115
116Gem5 Simulation Platform
117------------------------
118
119By initialising a Gem5SimulationPlatform, devlib will start a gem5 simulation (based upon the
120arguments the user provided) and then connect to it using :class:`Gem5Connection`.
121Using the methods discussed above, some methods of the :class:`Target` will be altered
122slightly to better suit gem5.
123
124.. class:: Gem5SimulationPlatform(name, host_output_dir, gem5_bin, gem5_args, gem5_virtio, gem5_telnet_port=None)
125
126    During initialisation the gem5 simulation will be kicked off (based upon the arguments
127    provided by the user) and the telnet port used by the gem5 simulation will be intercepted
128    and stored for use by the :class:`Gem5Connection`.
129
130    :param name: Platform name
131
132    :param host_output_dir: Path on the host where the gem5 outputs will be placed (e.g. stats file)
133
134    :param gem5_bin: gem5 binary
135
136    :param gem5_args: Arguments to be passed onto gem5 such as config file etc.
137
138    :param gem5_virtio: Arguments to be passed onto gem5 in terms of the virtIO device used
139                        to transfer files between the host and the gem5 simulated system.
140
141    :param gem5_telnet_port: Not yet in use as it would be used in future implementations
142                             of devlib in which the user could use the platform to pick
143                             up an existing and running simulation.
144
145
146.. method:: Gem5SimulationPlatform.init_target_connection([target])
147
148    Based upon the OS defined in the :class:`Target`, the type of :class:`Gem5Connection`
149    will be set (:class:`AndroidGem5Connection` or :class:`AndroidGem5Connection`).
150
151.. method:: Gem5SimulationPlatform.update_from_target([target])
152
153    This method provides specific setup procedures for a gem5 simulation. First of all, the m5
154    binary will be installed on the guest (if it is not present). Secondly, three methods
155    in the :class:`Target` will be monkey-patched:
156
157            - **reboot**: this is not supported in gem5
158            - **reset**: this is not supported in gem5
159            - **capture_screen**: gem5 might already have screencaps so the
160              monkey-patched method will first try to
161              transfer the existing screencaps.
162              In case that does not work, it will fall back
163              to the original :class:`Target` implementation
164              of :func:`capture_screen`.
165
166    Finally, it will call the parent implementation of :func:`update_from_target`.
167
168.. method:: Gem5SimulationPlatform.setup([target])
169
170    The m5 binary be installed, if not yet installed on the gem5 simulated system.
171    It will also resize the gem5 shell, to avoid line wrapping issues.
172