/*
* Copyright (c) 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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.
*
* Authors: Andreas Sandberg
*/
#ifndef __ARCH_ARM_SEMIHOSTING_HH__
#define __ARCH_ARM_SEMIHOSTING_HH__
#include <cstdio>
#include <map>
#include <memory>
#include <utility>
#include <vector>
#include "sim/sim_object.hh"
struct ArmSemihostingParams;
class PortProxy;
class SerialDevice;
class ThreadContext;
/**
* Semihosting for AArch32 and AArch64
*
* This class implements the Arm semihosting interface. This interface
* allows baremetal code access service, such as IO, from the
* simulator. It is conceptually a simplified version of gem5's more
* general syscall emulation mode.
*
* Exits calls (SYS_EXIT, SYS_EXIT_EXTENDED) from the guest get
* translated into simualtion exits. Well-known exit codes are
* translated to messages on the form 'semi:ADP_.*' while unknown
* codes are returned in hex ('semi:0x..'). The subcode is reported in
* the gem5 exit event.
*/
class ArmSemihosting : public SimObject
{
public:
ArmSemihosting(const ArmSemihostingParams *p);
/** Perform an Arm Semihosting call from aarch64 code. */
uint64_t call64(ThreadContext *tc, uint32_t op, uint64_t param);
/** Perform an Arm Semihosting call from aarch32 code. */
uint32_t call32(ThreadContext *tc, uint32_t op, uint32_t param);
public: // SimObject and related interfaces
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
protected: // Configuration
const std::string cmdLine;
const Addr memReserve;
const Addr stackSize;
/**
* Base time when the simulation started. This is used to
* calculate the time of date when the guest call SYS_TIME.
*/
const time_t timeBase;
/** Number of bits to right shift gem5 ticks to fit in a uint32_t */
const unsigned tickShift;
protected: // Internal state
typedef uint64_t SemiErrno;
SemiErrno semiErrno;
protected: // File IO
/**
* Internal state for open files
*
* This class describes the internal state of a file opened
* through the semihosting interface.
*
* A file instance is normally created using one of the
* ArmSemihosting::FileBase::create() factory methods. These
* methods handle some the magic file names in the Arm Semihosting
* specification and instantiate the right implementation. For the
* same, when unserializing a checkpoint, the create method must
* be used to unserialize a new instance of a file descriptor.
*/
class FileBase : public Serializable
{
public:
FileBase(ArmSemihosting &_parent, const char *name, const char *_mode)
: parent(_parent), _name(name), mode(_mode) {}
virtual ~FileBase() {};
FileBase() = delete;
FileBase(FileBase &) = delete;
static std::unique_ptr<FileBase> create(
ArmSemihosting &parent, const std::string &fname,
const char *mode);
static std::unique_ptr<FileBase> create(
ArmSemihosting &parent, CheckpointIn &cp, const std::string &sec);
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
const std::string &fileName() { return _name; }
public:
/** @{
* Semihosting file IO interfaces
*
* These interfaces implement common IO functionality in the
* Semihosting interface.
*
* All functions return a negative value that corresponds to a
* UNIX errno value when they fail and >=0 on success.
*/
/**
* Open the the file.
*
* @return <0 on error (-errno), 0 on success.
*/
virtual int64_t open() { return 0; }
/**
* Close the file.
*
* @return <0 on error (-errno), 0 on success.
*/
virtual int64_t close() { return 0; }
/**
* Check if a file corresponds to a TTY device.
*
* @return True if the file is a TTY, false otherwise.
*/
virtual bool isTTY() const { return false; }
/**
* Read data from file.
*
* @return <0 on error (-errno), bytes read on success (0 for EOF).
*/
virtual int64_t read(uint8_t *buffer, uint64_t size);
/**
* Write data to file.
*
* @return <0 on error (-errno), bytes written on success.
*/
virtual int64_t write(const uint8_t *buffer, uint64_t size);
/**
* Seek to an absolute position in the file.
*
* @param pos Byte offset from start of file.
* @return <0 on error (-errno), 0 on success.
*/
virtual int64_t seek(uint64_t pos);
/**
* Get the length of a file in bytes.
*
* @return <0 on error (-errno), length on success
*/
virtual int64_t flen();
/** @} */
protected:
ArmSemihosting &parent;
std::string _name;
std::string mode;
};
/** Implementation of the ':semihosting-features' magic file. */
class FileFeatures : public FileBase
{
public:
FileFeatures(ArmSemihosting &_parent,
const char *name, const char *mode);
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
int64_t read(uint8_t *buffer, uint64_t size) override;
int64_t seek(uint64_t pos) override;
protected:
size_t pos;
};
class File : public FileBase
{
public:
File(ArmSemihosting &_parent, const char *name, const char *mode);
~File();
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
int64_t open() override { return openImpl(false); }
int64_t close() override;
bool isTTY() const override;
int64_t read(uint8_t *buffer, uint64_t size) override;
int64_t write(const uint8_t *buffer, uint64_t size) override;
int64_t seek(uint64_t pos) override;
int64_t flen() override;
protected:
int64_t openImpl(bool unserialize);
bool needClose() const { return !isTTY(); }
FILE *file;
};
std::vector<std::unique_ptr<FileBase>> files;
FILE *stdin;
FILE *stdout;
FILE *stderr;
protected: // Helper functions
unsigned calcTickShift() const {
int msb = findMsbSet(SimClock::Frequency);
return msb > 31 ? msb - 31 : 0;
}
uint64_t semiTick(Tick tick) const {
return tick >> tickShift;
}
void semiExit(uint64_t code, uint64_t subcode);
PortProxy &physProxy(ThreadContext *tc);
std::string readString(ThreadContext *tc, Addr ptr, size_t len);
std::unique_ptr<PortProxy> physProxyS;
private:
typedef std::pair<uint64_t, SemiErrno> RetErrno;
static RetErrno retError(SemiErrno e) {
return RetErrno((uint64_t)-1, e);
}
static RetErrno retOK(uint64_t r) {
return RetErrno(r, 0);
}
/**
* Semihosting call information structure.
*
* This structure describes how a semi-hosting call is
* implemented. It contains debug information (e.g., the name of
* the call), a pointer to the implementation, and information
* needed to read its parameters from guest memory.
*/
struct SemiCall
{
/** Call name */
const char *name;
/**
* Pointer to call implementation
*
* @param tc ThreadContext pointer for caller
* @param aarch64 True if in aarc64 mode, false otherwise.
* @parma argv Argument vector. argv[0] always corresponds to
* the pointer to the argument list. Remaining
* entries are read as consecutive words starting
* at the address pointed to by argv[0].
* @return a (return value, errno) pair
*/
RetErrno (ArmSemihosting::*call)(ThreadContext *tc, bool aarch64,
std::vector<uint64_t> &argv);
/** Number of aarch32 arguments to read from guest memory. -1
* if unimplemented.*/
int argc32;
/** Number of aarch32 arguments to read from guest memory. -1
* if unimplemented.*/
int argc64;
/** Is call implemented in aarch32? */
bool implemented32() const { return call && argc32 >= 0; }
/** Is call implemented in aarch64? */
bool implemented64() const { return call && argc64 >= 0; }
};
#define SEMI_CALL(N) \
RetErrno call ## N (ThreadContext *tc, \
bool aarch64, std::vector<uint64_t> &argv)
SEMI_CALL(Open);
SEMI_CALL(Close);
SEMI_CALL(WriteC);
SEMI_CALL(Write0);
SEMI_CALL(Write);
SEMI_CALL(Read);
SEMI_CALL(ReadC);
SEMI_CALL(IsError);
SEMI_CALL(IsTTY);
SEMI_CALL(Seek);
SEMI_CALL(FLen);
SEMI_CALL(TmpNam);
SEMI_CALL(Remove);
SEMI_CALL(Rename);
SEMI_CALL(Clock);
SEMI_CALL(Time);
SEMI_CALL(System);
SEMI_CALL(Errno);
SEMI_CALL(GetCmdLine);
SEMI_CALL(HeapInfo);
SEMI_CALL(Exit);
SEMI_CALL(ExitExtended);
SEMI_CALL(Elapsed);
SEMI_CALL(TickFreq);
#undef SEMI_CALL
static const SemiCall *getCall(uint32_t op, bool aarch64);
static FILE *getSTDIO(const char *stream_name,
const std::string &name, const char *mode);
static const std::map<uint32_t, SemiCall> calls;
static const std::vector<const char *> fmodes;
static const std::map<uint64_t, const char *> exitCodes;
static const std::vector<uint8_t> features;
static const std::map<const std::string, FILE *> stdioMap;
};
#endif // __ARCH_ARM_SEMIHOSTING_HH__