include/gdb/remote-sim.h

   1 /* This file defines the interface between the simulator and gdb.
   2
   3    Copyright (C) 1993-2017 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (REMOTE_SIM_H)
  21 #define REMOTE_SIM_H 1
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif
  26
  27 /* This file is used when building stand-alone simulators, so isolate this
  28    file from gdb.  */
  29
  30 /* Pick up CORE_ADDR_TYPE if defined (from gdb), otherwise use same value as
  31    gdb does (unsigned int - from defs.h).  */
  32
  33 #ifndef CORE_ADDR_TYPE
  34 typedef unsigned int SIM_ADDR;
  35 #else
  36 typedef CORE_ADDR_TYPE SIM_ADDR;
  37 #endif
  38
  39
  40 /* Semi-opaque type used as result of sim_open and passed back to all
  41    other routines.  "desc" is short for "descriptor".
  42    It is up to each simulator to define `sim_state'.  */
  43
  44 typedef struct sim_state *SIM_DESC;
  45
  46
  47 /* Values for `kind' arg to sim_open.  */
  48
  49 typedef enum {
  50   SIM_OPEN_STANDALONE, /* simulator used standalone (run.c) */
  51   SIM_OPEN_DEBUG       /* simulator used by debugger (gdb) */
  52 } SIM_OPEN_KIND;
  53
  54
  55 /* Return codes from various functions.  */
  56
  57 typedef enum {
  58   SIM_RC_FAIL = 0,
  59   SIM_RC_OK = 1
  60 } SIM_RC;
  61
  62
  63 /* Some structs, as opaque types.  */
  64
  65 struct bfd;
  66 struct host_callback_struct;
  67
  68
  69 /* Main simulator entry points.  */
  70
  71
  72 /* Create a fully initialized simulator instance.
  73
  74    (This function is called when the simulator is selected from the
  75    gdb command line.)
  76
  77    KIND specifies how the simulator shall be used.  Currently there
  78    are only two kinds: stand-alone and debug.
  79
  80    CALLBACK specifies a standard host callback (defined in callback.h).
  81
  82    ABFD, when non NULL, designates a target program.  The program is
  83    not loaded.
  84
  85    ARGV is a standard ARGV pointer such as that passed from the
  86    command line.  The syntax of the argument list is is assumed to be
  87    ``SIM-PROG { SIM-OPTION } [ TARGET-PROGRAM { TARGET-OPTION } ]''.
  88    The trailing TARGET-PROGRAM and args are only valid for a
  89    stand-alone simulator.
  90
  91    On success, the result is a non NULL descriptor that shall be
  92    passed to the other sim_foo functions.  While the simulator
  93    configuration can be parameterized by (in decreasing precedence)
  94    ARGV's SIM-OPTION, ARGV's TARGET-PROGRAM and the ABFD argument, the
  95    successful creation of the simulator shall not dependent on the
  96    presence of any of these arguments/options.
  97
  98    Hardware simulator: The created simulator shall be sufficiently
  99    initialized to handle, with out restrictions any client requests
 100    (including memory reads/writes, register fetch/stores and a
 101    resume).
 102
 103    Process simulator: that process is not created until a call to
 104    sim_create_inferior.  FIXME: What should the state of the simulator
 105    be? */
 106
 107 SIM_DESC sim_open (SIM_OPEN_KIND kind, struct host_callback_struct *callback,
 108                    struct bfd *abfd, char * const *argv);
 109
 110
 111 /* Destory a simulator instance.
 112
 113    QUITTING is non-zero if we cannot hang on errors.
 114
 115    This may involve freeing target memory and closing any open files
 116    and mmap'd areas.  You cannot assume sim_kill has already been
 117    called. */
 118
 119 void sim_close (SIM_DESC sd, int quitting);
 120
 121
 122 /* Load program PROG into the simulators memory.
 123
 124    If ABFD is non-NULL, the bfd for the file has already been opened.
 125    The result is a return code indicating success.
 126
 127    Hardware simulator: Normally, each program section is written into
 128    memory according to that sections LMA using physical (direct)
 129    addressing.  The exception being systems, such as PPC/CHRP, which
 130    support more complicated program loaders.  A call to this function
 131    should not effect the state of the processor registers.  Multiple
 132    calls to this function are permitted and have an accumulative
 133    effect.
 134
 135    Process simulator: Calls to this function may be ignored.
 136
 137    FIXME: Most hardware simulators load the image at the VMA using
 138    virtual addressing.
 139
 140    FIXME: For some hardware targets, before a loaded program can be
 141    executed, it requires the manipulation of VM registers and tables.
 142    Such manipulation should probably (?) occure in
 143    sim_create_inferior. */
 144
 145 SIM_RC sim_load (SIM_DESC sd, const char *prog, struct bfd *abfd, int from_tty);
 146
 147
 148 /* Prepare to run the simulated program.
 149
 150    ABFD, if not NULL, provides initial processor state information.
 151    ARGV and ENV, if non NULL, are NULL terminated lists of pointers.
 152
 153    Hardware simulator: This function shall initialize the processor
 154    registers to a known value.  The program counter and possibly stack
 155    pointer shall be set using information obtained from ABFD (or
 156    hardware reset defaults).  ARGV and ENV, dependant on the target
 157    ABI, may be written to memory.
 158
 159    Process simulator: After a call to this function, a new process
 160    instance shall exist. The TEXT, DATA, BSS and stack regions shall
 161    all be initialized, ARGV and ENV shall be written to process
 162    address space (according to the applicable ABI) and the program
 163    counter and stack pointer set accordingly. */
 164
 165 SIM_RC sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 166                             char * const *argv, char * const *env);
 167
 168
 169 /* Fetch LENGTH bytes of the simulated program's memory.  Start fetch
 170    at virtual address MEM and store in BUF.  Result is number of bytes
 171    read, or zero if error.  */
 172
 173 int sim_read (SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length);
 174
 175
 176 /* Store LENGTH bytes from BUF into the simulated program's
 177    memory. Store bytes starting at virtual address MEM. Result is
 178    number of bytes write, or zero if error.  */
 179
 180 int sim_write (SIM_DESC sd, SIM_ADDR mem, const unsigned char *buf, int length);
 181
 182
 183 /* Fetch register REGNO storing its raw (target endian) value in the
 184    LENGTH byte buffer BUF.  Return the actual size of the register or
 185    zero if REGNO is not applicable.
 186
 187    Legacy implementations ignore LENGTH and always return -1.
 188
 189    If LENGTH does not match the size of REGNO no data is transfered
 190    (the actual register size is still returned). */
 191
 192 int sim_fetch_register (SIM_DESC sd, int regno, unsigned char *buf, int length);
 193
 194
 195 /* Store register REGNO from the raw (target endian) value in BUF.
 196
 197    Return the actual size of the register, any size not equal to
 198    LENGTH indicates the register was not updated correctly.
 199
 200    Return a LENGTH of -1 to indicate the register was not updated
 201    and an error has occurred.
 202
 203    Return a LENGTH of 0 to indicate the register was not updated
 204    but no error has occurred. */
 205
 206 int sim_store_register (SIM_DESC sd, int regno, unsigned char *buf, int length);
 207
 208
 209 /* Print whatever statistics the simulator has collected.
 210
 211    VERBOSE is currently unused and must always be zero.  */
 212
 213 void sim_info (SIM_DESC sd, int verbose);
 214
 215
 216 /* Run (or resume) the simulated program.
 217
 218    STEP, when non-zero indicates that only a single simulator cycle
 219    should be emulated.
 220
 221    SIGGNAL, if non-zero is a (HOST) SIGRC value indicating the type of
 222    event (hardware interrupt, signal) to be delivered to the simulated
 223    program.
 224
 225    Hardware simulator: If the SIGRC value returned by
 226    sim_stop_reason() is passed back to the simulator via SIGGNAL then
 227    the hardware simulator shall correctly deliver the hardware event
 228    indicated by that signal.  If a value of zero is passed in then the
 229    simulation will continue as if there were no outstanding signal.
 230    The effect of any other SIGGNAL value is is implementation
 231    dependant.
 232
 233    Process simulator: If SIGRC is non-zero then the corresponding
 234    signal is delivered to the simulated program and execution is then
 235    continued.  A zero SIGRC value indicates that the program should
 236    continue as normal. */
 237
 238 void sim_resume (SIM_DESC sd, int step, int siggnal);
 239
 240
 241 /* Asynchronous request to stop the simulation.
 242    A nonzero return indicates that the simulator is able to handle
 243    the request */
 244
 245 int sim_stop (SIM_DESC sd);
 246
 247
 248 /* Fetch the REASON why the program stopped.
 249
 250    SIM_EXITED: The program has terminated. SIGRC indicates the target
 251    dependant exit status.
 252
 253    SIM_STOPPED: The program has stopped.  SIGRC uses the host's signal
 254    numbering as a way of identifying the reaon: program interrupted by
 255    user via a sim_stop request (SIGINT); a breakpoint instruction
 256    (SIGTRAP); a completed single step (SIGTRAP); an internal error
 257    condition (SIGABRT); an illegal instruction (SIGILL); Access to an
 258    undefined memory region (SIGSEGV); Mis-aligned memory access
 259    (SIGBUS).  For some signals information in addition to the signal
 260    number may be retained by the simulator (e.g. offending address),
 261    that information is not directly accessable via this interface.
 262
 263    SIM_SIGNALLED: The program has been terminated by a signal. The
 264    simulator has encountered target code that causes the program
 265    to exit with signal SIGRC.
 266
 267    SIM_RUNNING, SIM_POLLING: The return of one of these values
 268    indicates a problem internal to the simulator. */
 269
 270 enum sim_stop { sim_running, sim_polling, sim_exited, sim_stopped, sim_signalled };
 271
 272 void sim_stop_reason (SIM_DESC sd, enum sim_stop *reason, int *sigrc);
 273
 274
 275 /* Passthru for other commands that the simulator might support.
 276    Simulators should be prepared to deal with any combination of NULL
 277    or empty CMD. */
 278
 279 void sim_do_command (SIM_DESC sd, const char *cmd);
 280
 281 /* Complete a command based on the available sim commands.  Returns an
 282    array of possible matches.  */
 283
 284 char **sim_complete_command (SIM_DESC sd, const char *text, const char *word);
 285
 286 #ifdef __cplusplus
 287 }
 288 #endif
 289
 290 #endif /* !defined (REMOTE_SIM_H) */