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Diffstat (limited to 'src/arch/arm/semihosting.hh')
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diff --git a/src/arch/arm/semihosting.hh b/src/arch/arm/semihosting.hh new file mode 100644 index 000000000..a4aa845a3 --- /dev/null +++ b/src/arch/arm/semihosting.hh @@ -0,0 +1,348 @@ +/* + * 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 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; + + 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); + std::string readString(ThreadContext *tc, Addr ptr, size_t len); + + private: + typedef std::pair<uint64_t, SemiErrno> RetErrno; + static constexpr RetErrno retError(SemiErrno e) { + return RetErrno((uint64_t)-1, e); + } + + static constexpr 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 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; +}; + +#endif // __ARCH_ARM_SEMIHOSTING_HH__ |