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authorSteve Reinhardt <steve.reinhardt@amd.com>2014-10-22 15:53:34 -0700
committerSteve Reinhardt <steve.reinhardt@amd.com>2014-10-22 15:53:34 -0700
commit44ec1d212499246be3cef40ce7c96a3f65286153 (patch)
tree503f72a85b24db8b82f792cd22341aeb0bdcd112
parent6523aad25c32f2443c48b114db4dab078bfb16d1 (diff)
downloadgem5-44ec1d212499246be3cef40ce7c96a3f65286153.tar.xz
syscall_emul: add EmulatedDriver object
Fake SE-mode device drivers can now be added by deriving from this abstract object.
-rw-r--r--src/sim/Process.py8
-rw-r--r--src/sim/emul_driver.hh90
-rw-r--r--src/sim/process.cc19
-rw-r--r--src/sim/process.hh15
-rw-r--r--src/sim/syscall_emul.hh36
5 files changed, 157 insertions, 11 deletions
diff --git a/src/sim/Process.py b/src/sim/Process.py
index 6f2322805..7e5f75363 100644
--- a/src/sim/Process.py
+++ b/src/sim/Process.py
@@ -46,6 +46,12 @@ class Process(SimObject):
def export_methods(cls, code):
code('bool map(Addr vaddr, Addr paddr, int size);')
+class EmulatedDriver(SimObject):
+ type = 'EmulatedDriver'
+ cxx_header = "sim/emul_driver.hh"
+ abstract = True
+ filename = Param.String("device file name (under /dev)")
+
class LiveProcess(Process):
type = 'LiveProcess'
cxx_header = "sim/process.hh"
@@ -60,3 +66,5 @@ class LiveProcess(Process):
pid = Param.Int(100, 'process id')
ppid = Param.Int(99, 'parent process id')
simpoint = Param.UInt64(0, 'simulation point at which to start simulation')
+ drivers = VectorParam.EmulatedDriver([], 'Available emulated drivers')
+
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
diff --git a/src/sim/process.cc b/src/sim/process.cc
index 913e9298d..15dc8c3e8 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -278,7 +278,7 @@ Process::alloc_fd(int sim_fd, string filename, int flags, int mode, bool pipe)
// find first free target fd
for (int free_fd = 0; free_fd <= MAX_FD; ++free_fd) {
Process::FdMap *fdo = &fd_map[free_fd];
- if (fdo->fd == -1) {
+ if (fdo->fd == -1 && fdo->driver == NULL) {
fdo->fd = sim_fd;
fdo->filename = filename;
fdo->mode = mode;
@@ -309,6 +309,7 @@ Process::free_fd(int tgt_fd)
fdo->flags = 0;
fdo->isPipe = false;
fdo->readPipeSource = 0;
+ fdo->driver = NULL;
}
@@ -567,7 +568,8 @@ Process::map(Addr vaddr, Addr paddr, int size)
LiveProcess::LiveProcess(LiveProcessParams * params, ObjectFile *_objFile)
: Process(params), objFile(_objFile),
- argv(params->cmd), envp(params->env), cwd(params->cwd)
+ argv(params->cmd), envp(params->env), cwd(params->cwd),
+ drivers(params->drivers)
{
__uid = params->uid;
__euid = params->euid;
@@ -608,6 +610,19 @@ LiveProcess::getSyscallArg(ThreadContext *tc, int &i, int width)
return getSyscallArg(tc, i);
}
+
+EmulatedDriver *
+LiveProcess::findDriver(std::string filename)
+{
+ for (EmulatedDriver *d : drivers) {
+ if (d->match(filename))
+ return d;
+ }
+
+ return NULL;
+}
+
+
LiveProcess *
LiveProcess::create(LiveProcessParams * params)
{
diff --git a/src/sim/process.hh b/src/sim/process.hh
index 03380acf7..6e26bb8bd 100644
--- a/src/sim/process.hh
+++ b/src/sim/process.hh
@@ -50,6 +50,7 @@ struct LiveProcessParams;
class SyscallDesc;
class System;
class ThreadContext;
+class EmulatedDriver;
template<class IntType>
struct AuxVector
@@ -139,10 +140,11 @@ class Process : public SimObject
bool isPipe;
int readPipeSource;
uint64_t fileOffset;
+ EmulatedDriver *driver;
FdMap()
: fd(-1), filename("NULL"), mode(0), flags(0),
- isPipe(false), readPipeSource(0), fileOffset(0)
+ isPipe(false), readPipeSource(0), fileOffset(0), driver(NULL)
{ }
void serialize(std::ostream &os);
@@ -256,6 +258,9 @@ class LiveProcess : public Process
uint64_t __pid;
uint64_t __ppid;
+ // Emulated drivers available to this process
+ std::vector<EmulatedDriver *> drivers;
+
public:
enum AuxiliaryVectorType {
@@ -325,6 +330,14 @@ class LiveProcess : public Process
virtual SyscallDesc *getDesc(int callnum) = 0;
+ /**
+ * Find an emulated device driver.
+ *
+ * @param filename Name of the device (under /dev)
+ * @return Pointer to driver object if found, else NULL
+ */
+ EmulatedDriver *findDriver(std::string filename);
+
// this function is used to create the LiveProcess object, since
// we can't tell which subclass of LiveProcess to use until we
// open and look at the object file.
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index dff34982d..1c84e9f48 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -77,6 +77,7 @@
#include "mem/page_table.hh"
#include "mem/se_translating_port_proxy.hh"
#include "sim/byteswap.hh"
+#include "sim/emul_driver.hh"
#include "sim/process.hh"
#include "sim/syscallreturn.hh"
#include "sim/system.hh"
@@ -604,11 +605,17 @@ ioctlFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
DPRINTF(SyscallVerbose, "ioctl(%d, 0x%x, ...)\n", fd, req);
- if (fd < 0 || process->sim_fd(fd) < 0) {
+ Process::FdMap *fdObj = process->sim_fd_obj(fd);
+
+ if (fdObj == NULL) {
// doesn't map to any simulator fd: not a valid target fd
return -EBADF;
}
+ if (fdObj->driver != NULL) {
+ return fdObj->driver->ioctl(process, tc, req);
+ }
+
if (OS::isTtyReq(req)) {
return -ENOTTY;
}
@@ -629,13 +636,6 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
process->getSyscallArg(tc, index)))
return -EFAULT;
- if (path == "/dev/sysdev0") {
- // This is a memory-mapped high-resolution timer device on Alpha.
- // We don't support it, so just punt.
- warn("Ignoring open(%s, ...)\n", path);
- return -ENOENT;
- }
-
int tgtFlags = process->getSyscallArg(tc, index);
int mode = process->getSyscallArg(tc, index);
int hostFlags = 0;
@@ -661,6 +661,26 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
DPRINTF(SyscallVerbose, "opening file %s\n", path.c_str());
+ if (startswith(path, "/dev/")) {
+ std::string filename = path.substr(strlen("/dev/"));
+ if (filename == "sysdev0") {
+ // This is a memory-mapped high-resolution timer device on Alpha.
+ // We don't support it, so just punt.
+ warn("Ignoring open(%s, ...)\n", path);
+ return -ENOENT;
+ }
+
+ EmulatedDriver *drv = process->findDriver(filename);
+ if (drv != NULL) {
+ // the driver's open method will allocate a fd from the
+ // process if necessary.
+ return drv->open(process, tc, mode, hostFlags);
+ }
+
+ // fall through here for pass through to host devices, such as
+ // /dev/zero
+ }
+
int fd;
int local_errno;
if (startswith(path, "/proc/") || startswith(path, "/system/") ||