syscall_emul: add EmulatedDriver object

Fake SE-mode device drivers can now be added by
deriving from this abstract object.

1 files changed, 90 insertions, 0 deletions

diff --git a/src/sim/emul_driver.hh b/src/sim/emul_driver.hh
new file mode 100644
index 000000000..778fc6461
--- /dev/null
+++ b/src/sim/emul_driver.hh
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2014 Advanced Micro Devices, Inc.
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Steve Reinhardt
+ */
+
+#ifndef __SIM_EMUL_DRIVER_HH
+#define __SIM_EMUL_DRIVER_HH
+
+#include <string>
+
+#include "params/EmulatedDriver.hh"
+#include "sim/sim_object.hh"
+
+class LiveProcess;
+class ThreadContext;
+
+/**
+ * EmulatedDriver is an abstract base class for fake SE-mode device drivers.
+ *
+ * Specific drivers that allow applications to communicate with simulated
+ * hardware inside gem5 can be created by deriving from this class and
+ * overriding the abstract virtual methods.
+ *
+ * Currently only open() and ioctl() calls are supported, but other calls
+ * (e.g., read(), write(), mmap()) could be added as needed.
+ */
+class EmulatedDriver : public SimObject
+{
+  protected:
+    /**
+     * filename for opening this driver (under /dev)
+     */
+    const std::string &filename;
+
+  public:
+    EmulatedDriver(EmulatedDriverParams *p)
+        : SimObject(p), filename(p->filename)
+    {
+    }
+
+    /**
+     * Check for a match with this driver's filename.
+     */
+    bool match(const std::string &s) const { return (s == filename); }
+
+    /**
+     * Abstract method, invoked when the user program calls open() on
+     * the device driver.  The parameters are the same as those passed
+     * to openFunc() (q.v.).
+     * @return A newly allocated target fd, or -1 on error.
+     */
+    virtual int open(LiveProcess *p, ThreadContext *tc,
+                     int mode, int flags) = 0;
+
+    /**
+     * Abstract method, invoked when the user program calls ioctl() on
+     * the file descriptor returned by a previous open().  The parameters
+     * are the same as those passed in to ioctlFunc() (q.v.).
+     * @return The return code for the ioctl, or the negation of the errno
+     * (see the SyscallReturn class).
+     */
+    virtual int ioctl(LiveProcess *p, ThreadContext *tc, unsigned req) = 0;
+};
+
+#endif // __SIM_EMUL_DRIVER_HH