include/sim/sim.h

   1 /* This file defines the interface between the simulator and gdb.
   2
   3    Copyright (C) 1993-2024 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 <stdbool.h>
  24 #include <stdint.h>
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 /* Semi-opaque type used as result of sim_open and passed back to all
  31    other routines.  "desc" is short for "descriptor".
  32    It is up to each simulator to define `sim_state'.  */
  33
  34 typedef struct sim_state *SIM_DESC;
  35
  36
  37 /* Values for `kind' arg to sim_open.  */
  38
  39 typedef enum {
  40   SIM_OPEN_STANDALONE, /* simulator used standalone (run.c) */
  41   SIM_OPEN_DEBUG       /* simulator used by debugger (gdb) */
  42 } SIM_OPEN_KIND;
  43
  44
  45 /* Return codes from various functions.  */
  46
  47 typedef enum {
  48   SIM_RC_FAIL = 0,
  49   SIM_RC_OK = 1
  50 } SIM_RC;
  51
  52
  53 /* Some structs, as opaque types.  */
  54
  55 struct bfd;
  56 struct host_callback_struct;
  57
  58
  59 /* Main simulator entry points.  */
  60
  61
  62 /* Create a fully initialized simulator instance.
  63
  64    (This function is called when the simulator is selected from the
  65    gdb command line.)
  66
  67    KIND specifies how the simulator shall be used.  Currently there
  68    are only two kinds: stand-alone and debug.
  69
  70    CALLBACK specifies a standard host callback (defined in callback.h).
  71
  72    ABFD, when non NULL, designates a target program.  The program is
  73    not loaded.
  74
  75    ARGV is a standard ARGV pointer such as that passed from the
  76    command line.  The syntax of the argument list is is assumed to be
  77    ``SIM-PROG { SIM-OPTION } [ TARGET-PROGRAM { TARGET-OPTION } ]''.
  78    The trailing TARGET-PROGRAM and args are only valid for a
  79    stand-alone simulator.
  80
  81    On success, the result is a non NULL descriptor that shall be
  82    passed to the other sim_foo functions.  While the simulator
  83    configuration can be parameterized by (in decreasing precedence)
  84    ARGV's SIM-OPTION, ARGV's TARGET-PROGRAM and the ABFD argument, the
  85    successful creation of the simulator shall not dependent on the
  86    presence of any of these arguments/options.
  87
  88    Hardware simulator: The created simulator shall be sufficiently
  89    initialized to handle, with out restrictions any client requests
  90    (including memory reads/writes, register fetch/stores and a
  91    resume).
  92
  93    Process simulator: that process is not created until a call to
  94    sim_create_inferior.  FIXME: What should the state of the simulator
  95    be? */
  96
  97 SIM_DESC sim_open (SIM_OPEN_KIND kind, struct host_callback_struct *callback,
  98                    struct bfd *abfd, char * const *argv);
  99
 100
 101 /* Destory a simulator instance.
 102
 103    QUITTING is non-zero if we cannot hang on errors.
 104
 105    This may involve freeing target memory and closing any open files
 106    and mmap'd areas.  You cannot assume sim_kill has already been
 107    called. */
 108
 109 void sim_close (SIM_DESC sd, int quitting);
 110
 111
 112 /* Load program PROG into the simulators memory.
 113
 114    If ABFD is non-NULL, the bfd for the file has already been opened.
 115    The result is a return code indicating success.
 116
 117    Hardware simulator: Normally, each program section is written into
 118    memory according to that sections LMA using physical (direct)
 119    addressing.  The exception being systems, such as PPC/CHRP, which
 120    support more complicated program loaders.  A call to this function
 121    should not effect the state of the processor registers.  Multiple
 122    calls to this function are permitted and have an accumulative
 123    effect.
 124
 125    Process simulator: Calls to this function may be ignored.
 126
 127    FIXME: Most hardware simulators load the image at the VMA using
 128    virtual addressing.
 129
 130    FIXME: For some hardware targets, before a loaded program can be
 131    executed, it requires the manipulation of VM registers and tables.
 132    Such manipulation should probably (?) occure in
 133    sim_create_inferior. */
 134
 135 SIM_RC sim_load (SIM_DESC sd, const char *prog, struct bfd *abfd, int from_tty);
 136
 137
 138 /* Prepare to run the simulated program.
 139
 140    ABFD, if not NULL, provides initial processor state information.
 141    ARGV and ENV, if non NULL, are NULL terminated lists of pointers.
 142
 143    Hardware simulator: This function shall initialize the processor
 144    registers to a known value.  The program counter and possibly stack
 145    pointer shall be set using information obtained from ABFD (or
 146    hardware reset defaults).  ARGV and ENV, dependant on the target
 147    ABI, may be written to memory.
 148
 149    Process simulator: After a call to this function, a new process
 150    instance shall exist. The TEXT, DATA, BSS and stack regions shall
 151    all be initialized, ARGV and ENV shall be written to process
 152    address space (according to the applicable ABI) and the program
 153    counter and stack pointer set accordingly. */
 154
 155 SIM_RC sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 156                             char * const *argv, char * const *env);
 157
 158
 159 /* Fetch LENGTH bytes of the simulated program's memory.  Start fetch
 160    at virtual address MEM and store in BUF.  Result is number of bytes
 161    read, or zero if error.  */
 162
 163 uint64_t sim_read (SIM_DESC sd, uint64_t mem, void *buf, uint64_t length);
 164
 165
 166 /* Store LENGTH bytes from BUF into the simulated program's
 167    memory. Store bytes starting at virtual address MEM. Result is
 168    number of bytes write, or zero if error.  */
 169
 170 uint64_t sim_write (SIM_DESC sd, uint64_t mem, const void *buf, uint64_t length);
 171
 172
 173 /* Fetch register REGNO storing its raw (target endian) value in the
 174    LENGTH byte buffer BUF.  Return the actual size of the register or
 175    zero if REGNO is not applicable.
 176
 177    Legacy implementations ignore LENGTH and always return -1.
 178
 179    If LENGTH does not match the size of REGNO no data is transfered
 180    (the actual register size is still returned). */
 181
 182 int sim_fetch_register (SIM_DESC sd, int regno, void *buf, int length);
 183
 184
 185 /* Store register REGNO from the raw (target endian) value in BUF.
 186
 187    Return the actual size of the register, any size not equal to
 188    LENGTH indicates the register was not updated correctly.
 189
 190    Return a LENGTH of -1 to indicate the register was not updated
 191    and an error has occurred.
 192
 193    Return a LENGTH of 0 to indicate the register was not updated
 194    but no error has occurred. */
 195
 196 int sim_store_register (SIM_DESC sd, int regno, const void *buf, int length);
 197
 198
 199 /* Print whatever statistics the simulator has collected.
 200
 201    When VERBOSE is enabled, extra details will be shown.  */
 202
 203 void sim_info (SIM_DESC sd, bool verbose);
 204
 205
 206 /* Return a memory map in XML format.
 207
 208    The caller must free the returned string.
 209
 210    For details on the format, see GDB's Memory Map Format documentation.  */
 211
 212 char *sim_memory_map (SIM_DESC sd);
 213
 214
 215 /* Run (or resume) the simulated program.
 216
 217    STEP, when non-zero indicates that only a single simulator cycle
 218    should be emulated.
 219
 220    SIGGNAL, if non-zero is a (HOST) SIGRC value indicating the type of
 221    event (hardware interrupt, signal) to be delivered to the simulated
 222    program.
 223
 224    Hardware simulator: If the SIGRC value returned by
 225    sim_stop_reason() is passed back to the simulator via SIGGNAL then
 226    the hardware simulator shall correctly deliver the hardware event
 227    indicated by that signal.  If a value of zero is passed in then the
 228    simulation will continue as if there were no outstanding signal.
 229    The effect of any other SIGGNAL value is is implementation
 230    dependant.
 231
 232    Process simulator: If SIGRC is non-zero then the corresponding
 233    signal is delivered to the simulated program and execution is then
 234    continued.  A zero SIGRC value indicates that the program should
 235    continue as normal. */
 236
 237 void sim_resume (SIM_DESC sd, int step, int siggnal);
 238
 239
 240 /* Asynchronous request to stop the simulation.
 241    A nonzero return indicates that the simulator is able to handle
 242    the request */
 243
 244 int sim_stop (SIM_DESC sd);
 245
 246
 247 /* Fetch the REASON why the program stopped.
 248
 249    SIM_EXITED: The program has terminated. SIGRC indicates the target
 250    dependant exit status.
 251
 252    SIM_STOPPED: The program has stopped.  SIGRC uses the host's signal
 253    numbering as a way of identifying the reaon: program interrupted by
 254    user via a sim_stop request (SIGINT); a breakpoint instruction
 255    (SIGTRAP); a completed single step (SIGTRAP); an internal error
 256    condition (SIGABRT); an illegal instruction (SIGILL); Access to an
 257    undefined memory region (SIGSEGV); Mis-aligned memory access
 258    (SIGBUS).  For some signals information in addition to the signal
 259    number may be retained by the simulator (e.g. offending address),
 260    that information is not directly accessable via this interface.
 261
 262    SIM_SIGNALLED: The program has been terminated by a signal. The
 263    simulator has encountered target code that causes the program
 264    to exit with signal SIGRC.
 265
 266    SIM_RUNNING, SIM_POLLING: The return of one of these values
 267    indicates a problem internal to the simulator. */
 268
 269 enum sim_stop { sim_running, sim_polling, sim_exited, sim_stopped, sim_signalled };
 270
 271 void sim_stop_reason (SIM_DESC sd, enum sim_stop *reason, int *sigrc);
 272
 273
 274 /* Passthru for other commands that the simulator might support.
 275    Simulators should be prepared to deal with any combination of NULL
 276    or empty CMD. */
 277
 278 void sim_do_command (SIM_DESC sd, const char *cmd);
 279
 280 /* Complete a command based on the available sim commands.  Returns an
 281    array of possible matches.  */
 282
 283 char **sim_complete_command (SIM_DESC sd, const char *text, const char *word);
 284
 285 #ifdef __cplusplus
 286 }
 287 #endif
 288
 289 #endif /* !defined (SIM_SIM_H) */