include/sim/sim.h

   1 /* This file defines the interface between the simulator and gdb.
   2
   3    Copyright (C) 1993-2023 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 #ifndef SIM_SIM_H
  21 #define SIM_SIM_H 1
  22
  23 #include <stdint.h>
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 /* Semi-opaque type used as result of sim_open and passed back to all
  30    other routines.  "desc" is short for "descriptor".
  31    It is up to each simulator to define `sim_state'.  */
  32
  33 typedef struct sim_state *SIM_DESC;
  34
  35
  36 /* Values for `kind' arg to sim_open.  */
  37
  38 typedef enum {
  39   SIM_OPEN_STANDALONE, /* simulator used standalone (run.c) */
  40   SIM_OPEN_DEBUG       /* simulator used by debugger (gdb) */
  41 } SIM_OPEN_KIND;
  42
  43
  44 /* Return codes from various functions.  */
  45
  46 typedef enum {
  47   SIM_RC_FAIL = 0,
  48   SIM_RC_OK = 1
  49 } SIM_RC;
  50
  51
  52 /* Some structs, as opaque types.  */
  53
  54 struct bfd;
  55 struct host_callback_struct;
  56
  57
  58 /* Main simulator entry points.  */
  59
  60
  61 /* Create a fully initialized simulator instance.
  62
  63    (This function is called when the simulator is selected from the
  64    gdb command line.)
  65
  66    KIND specifies how the simulator shall be used.  Currently there
  67    are only two kinds: stand-alone and debug.
  68
  69    CALLBACK specifies a standard host callback (defined in callback.h).
  70
  71    ABFD, when non NULL, designates a target program.  The program is
  72    not loaded.
  73
  74    ARGV is a standard ARGV pointer such as that passed from the
  75    command line.  The syntax of the argument list is is assumed to be
  76    ``SIM-PROG { SIM-OPTION } [ TARGET-PROGRAM { TARGET-OPTION } ]''.
  77    The trailing TARGET-PROGRAM and args are only valid for a
  78    stand-alone simulator.
  79
  80    On success, the result is a non NULL descriptor that shall be
  81    passed to the other sim_foo functions.  While the simulator
  82    configuration can be parameterized by (in decreasing precedence)
  83    ARGV's SIM-OPTION, ARGV's TARGET-PROGRAM and the ABFD argument, the
  84    successful creation of the simulator shall not dependent on the
  85    presence of any of these arguments/options.
  86
  87    Hardware simulator: The created simulator shall be sufficiently
  88    initialized to handle, with out restrictions any client requests
  89    (including memory reads/writes, register fetch/stores and a
  90    resume).
  91
  92    Process simulator: that process is not created until a call to
  93    sim_create_inferior.  FIXME: What should the state of the simulator
  94    be? */
  95
  96 SIM_DESC sim_open (SIM_OPEN_KIND kind, struct host_callback_struct *callback,
  97                    struct bfd *abfd, char * const *argv);
  98
  99
 100 /* Destory a simulator instance.
 101
 102    QUITTING is non-zero if we cannot hang on errors.
 103
 104    This may involve freeing target memory and closing any open files
 105    and mmap'd areas.  You cannot assume sim_kill has already been
 106    called. */
 107
 108 void sim_close (SIM_DESC sd, int quitting);
 109
 110
 111 /* Load program PROG into the simulators memory.
 112
 113    If ABFD is non-NULL, the bfd for the file has already been opened.
 114    The result is a return code indicating success.
 115
 116    Hardware simulator: Normally, each program section is written into
 117    memory according to that sections LMA using physical (direct)
 118    addressing.  The exception being systems, such as PPC/CHRP, which
 119    support more complicated program loaders.  A call to this function
 120    should not effect the state of the processor registers.  Multiple
 121    calls to this function are permitted and have an accumulative
 122    effect.
 123
 124    Process simulator: Calls to this function may be ignored.
 125
 126    FIXME: Most hardware simulators load the image at the VMA using
 127    virtual addressing.
 128
 129    FIXME: For some hardware targets, before a loaded program can be
 130    executed, it requires the manipulation of VM registers and tables.
 131    Such manipulation should probably (?) occure in
 132    sim_create_inferior. */
 133
 134 SIM_RC sim_load (SIM_DESC sd, const char *prog, struct bfd *abfd, int from_tty);
 135
 136
 137 /* Prepare to run the simulated program.
 138
 139    ABFD, if not NULL, provides initial processor state information.
 140    ARGV and ENV, if non NULL, are NULL terminated lists of pointers.
 141
 142    Hardware simulator: This function shall initialize the processor
 143    registers to a known value.  The program counter and possibly stack
 144    pointer shall be set using information obtained from ABFD (or
 145    hardware reset defaults).  ARGV and ENV, dependant on the target
 146    ABI, may be written to memory.
 147
 148    Process simulator: After a call to this function, a new process
 149    instance shall exist. The TEXT, DATA, BSS and stack regions shall
 150    all be initialized, ARGV and ENV shall be written to process
 151    address space (according to the applicable ABI) and the program
 152    counter and stack pointer set accordingly. */
 153
 154 SIM_RC sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 155                             char * const *argv, char * const *env);
 156
 157
 158 /* Fetch LENGTH bytes of the simulated program's memory.  Start fetch
 159    at virtual address MEM and store in BUF.  Result is number of bytes
 160    read, or zero if error.  */
 161
 162 uint64_t sim_read (SIM_DESC sd, uint64_t mem, void *buf, uint64_t length);
 163
 164
 165 /* Store LENGTH bytes from BUF into the simulated program's
 166    memory. Store bytes starting at virtual address MEM. Result is
 167    number of bytes write, or zero if error.  */
 168
 169 uint64_t sim_write (SIM_DESC sd, uint64_t mem, const void *buf, uint64_t length);
 170
 171
 172 /* Fetch register REGNO storing its raw (target endian) value in the
 173    LENGTH byte buffer BUF.  Return the actual size of the register or
 174    zero if REGNO is not applicable.
 175
 176    Legacy implementations ignore LENGTH and always return -1.
 177
 178    If LENGTH does not match the size of REGNO no data is transfered
 179    (the actual register size is still returned). */
 180
 181 int sim_fetch_register (SIM_DESC sd, int regno, void *buf, int length);
 182
 183
 184 /* Store register REGNO from the raw (target endian) value in BUF.
 185
 186    Return the actual size of the register, any size not equal to
 187    LENGTH indicates the register was not updated correctly.
 188
 189    Return a LENGTH of -1 to indicate the register was not updated
 190    and an error has occurred.
 191
 192    Return a LENGTH of 0 to indicate the register was not updated
 193    but no error has occurred. */
 194
 195 int sim_store_register (SIM_DESC sd, int regno, const void *buf, int length);
 196
 197
 198 /* Print whatever statistics the simulator has collected.
 199
 200    VERBOSE is currently unused and must always be zero.  */
 201
 202 void sim_info (SIM_DESC sd, int verbose);
 203
 204
 205 /* Return a memory map in XML format.
 206
 207    The caller must free the returned string.
 208
 209    For details on the format, see GDB's Memory Map Format documentation.  */
 210
 211 char *sim_memory_map (SIM_DESC sd);
 212
 213
 214 /* Run (or resume) the simulated program.
 215
 216    STEP, when non-zero indicates that only a single simulator cycle
 217    should be emulated.
 218
 219    SIGGNAL, if non-zero is a (HOST) SIGRC value indicating the type of
 220    event (hardware interrupt, signal) to be delivered to the simulated
 221    program.
 222
 223    Hardware simulator: If the SIGRC value returned by
 224    sim_stop_reason() is passed back to the simulator via SIGGNAL then
 225    the hardware simulator shall correctly deliver the hardware event
 226    indicated by that signal.  If a value of zero is passed in then the
 227    simulation will continue as if there were no outstanding signal.
 228    The effect of any other SIGGNAL value is is implementation
 229    dependant.
 230
 231    Process simulator: If SIGRC is non-zero then the corresponding
 232    signal is delivered to the simulated program and execution is then
 233    continued.  A zero SIGRC value indicates that the program should
 234    continue as normal. */
 235
 236 void sim_resume (SIM_DESC sd, int step, int siggnal);
 237
 238
 239 /* Asynchronous request to stop the simulation.
 240    A nonzero return indicates that the simulator is able to handle
 241    the request */
 242
 243 int sim_stop (SIM_DESC sd);
 244
 245
 246 /* Fetch the REASON why the program stopped.
 247
 248    SIM_EXITED: The program has terminated. SIGRC indicates the target
 249    dependant exit status.
 250
 251    SIM_STOPPED: The program has stopped.  SIGRC uses the host's signal
 252    numbering as a way of identifying the reaon: program interrupted by
 253    user via a sim_stop request (SIGINT); a breakpoint instruction
 254    (SIGTRAP); a completed single step (SIGTRAP); an internal error
 255    condition (SIGABRT); an illegal instruction (SIGILL); Access to an
 256    undefined memory region (SIGSEGV); Mis-aligned memory access
 257    (SIGBUS).  For some signals information in addition to the signal
 258    number may be retained by the simulator (e.g. offending address),
 259    that information is not directly accessable via this interface.
 260
 261    SIM_SIGNALLED: The program has been terminated by a signal. The
 262    simulator has encountered target code that causes the program
 263    to exit with signal SIGRC.
 264
 265    SIM_RUNNING, SIM_POLLING: The return of one of these values
 266    indicates a problem internal to the simulator. */
 267
 268 enum sim_stop { sim_running, sim_polling, sim_exited, sim_stopped, sim_signalled };
 269
 270 void sim_stop_reason (SIM_DESC sd, enum sim_stop *reason, int *sigrc);
 271
 272
 273 /* Passthru for other commands that the simulator might support.
 274    Simulators should be prepared to deal with any combination of NULL
 275    or empty CMD. */
 276
 277 void sim_do_command (SIM_DESC sd, const char *cmd);
 278
 279 /* Complete a command based on the available sim commands.  Returns an
 280    array of possible matches.  */
 281
 282 char **sim_complete_command (SIM_DESC sd, const char *text, const char *word);
 283
 284 #ifdef __cplusplus
 285 }
 286 #endif
 287
 288 #endif /* !defined (SIM_SIM_H) */