projects / OpenSPARC-T2-SAM / blame
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1 | <html> |
| 2 | ||
| 3 | <head> | |
| 4 | <title>SPARC Architectural Model: Device and Utility API</title> | |
| 5 | </head> | |
| 6 | ||
| 7 | <body bgcolor="#FFFFFF" LANG="en-US"> | |
| 8 | ||
| 9 | <h2>Introduction</h2> | |
| 10 | This document describes the MMI (Module Model Interface) device-model API | |
| 11 | for the SPARC Architectural Model (SAM). A SAM device model is built as a | |
| 12 | shared library (loadable module) which is dynamically loaded into SAM during | |
| 13 | initialization. | |
| 14 | <p> | |
| 15 | The <tt>sysconf</tt> directives in the input configuration file specify the device module, instance name and its associated properties. | |
| 16 | <p> | |
| 17 | API function and type names are prefixed with <tt>mmi_</tt>. | |
| 18 | <p> | |
| 19 | <h4>Attaching Modules</h4> | |
| 20 | ||
| 21 | <li> A device-model is typically contained within a shared object (.so file). A shared object typically has only one visible module that plugs into SAM. | |
| 22 | Internally within the device model, there can be a hierarchy of components (for example, Niagara ethernet module).</li><br> | |
| 23 | ||
| 24 | <li>An <i>instance</i> is what actually represents a device in SAM. There are generally multiple instances of a given device module.</li><br> | |
| 25 | ||
| 26 | <li> <a href="sysconf.html">The <tt><b>sysconf</b></tt> directive</a> | |
| 27 | <p><ul> | |
| 28 | <tt>sysconf</tt> directives are specified in the simulation configuration file. Each sysconf line specifies | |
| 29 | the module to be loaded if necessary, and the name of the device node to be instantiated. To properly instantiate the device node, | |
| 30 | SAM calls the instance creator function registered from within the module. | |
| 31 | </ul> </li> | |
| 32 | </ul> | |
| 33 | ||
| 34 | <h4> The <tt>mmi_instance_t</tt> handle</h4> | |
| 35 | ||
| 36 | Each instance can be referred to using an opaque <tt>mmi_instance_t</tt> handle. This includes code referring to its own instance (eg to register certain callback functions) as well as other instances (eg to get an exported interface) | |
| 37 | ||
| 38 | <h4>Threading Model </h4> | |
| 39 | ||
| 40 | SAM can be run in multi-threaded mode. It is recommended that module developers for SAM | |
| 41 | assume that simulated SPARCv9 CPUs may be bound to separate host threads, running on different | |
| 42 | processors on the host machine running the simulation. | |
| 43 | <p> | |
| 44 | A strand, however, is never simulated by more than one simulation thread, and | |
| 45 | when a strand performs a callback to the module it may be assumed that strand | |
| 46 | execution is stopped at the point of callback. | |
| 47 | ||
| 48 | <h4>Module to Module Interaction </h4> | |
| 49 | ||
| 50 | Modules may be loaded in any order (as specified in the sysconf file). In some cases, modules may be unloaded at any time. | |
| 51 | The SAM sysconf mechanism does not allow for device modules to be unloaded but the older <tt>ldm</tt> UI command does allow this. | |
| 52 | <p> | |
| 53 | Each module is notified when another module changes status | |
| 54 | (<a href="mmi_register_config_cb.html">mmi_register_config_cb</a>). | |
| 55 | <p> | |
| 56 | Modules may call each other by getting pointers to their interfaces | |
| 57 | (<a href=" mmi_get_interface.html">mmi_get_interface</a>). | |
| 58 | When a module is unloaded, other modules should receive the corresponding config change notification | |
| 59 | and remove their interface pointers to the unloaded module. | |
| 60 | ||
| 61 | <p> | |
| 62 | <hr> | |
| 63 | </body> | |
| 64 | ||
| 65 | </html> |