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- /* Remote target system call callback support.
- Copyright (C) 1997-2022 Free Software Foundation, Inc.
- Contributed by Cygnus Solutions.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /* This interface isn't intended to be specific to any particular kind
- of remote (hardware, simulator, whatever). As such, support for it
- (e.g. sim/common/callback.c) should *not* live in the simulator source
- tree, nor should it live in the gdb source tree. */
- /* There are various ways to handle system calls:
- 1) Have a simulator intercept the appropriate trap instruction and
- directly perform the system call on behalf of the target program.
- This is the typical way of handling system calls for embedded targets.
- [Handling system calls for embedded targets isn't that much of an
- oxymoron as running compiler testsuites make use of the capability.]
- This method of system call handling is done when STATE_ENVIRONMENT
- is ENVIRONMENT_USER.
- 2) Have a simulator emulate the hardware as much as possible.
- If the program running on the real hardware communicates with some sort
- of target manager, one would want to be able to run this program on the
- simulator as well.
- This method of system call handling is done when STATE_ENVIRONMENT
- is ENVIRONMENT_OPERATING.
- */
- #ifndef SIM_CALLBACK_H
- #define SIM_CALLBACK_H
- #include <stdarg.h>
- #include <stdint.h>
- #include <ansidecl.h>
- /* Needed for enum bfd_endian. */
- #include <bfd.h>
- /* Mapping of host/target values. */
- /* ??? For debugging purposes, one might want to add a string of the
- name of the symbol. */
- typedef struct {
- const char *name;
- int host_val;
- int target_val;
- } CB_TARGET_DEFS_MAP;
- #define MAX_CALLBACK_FDS 10
- /* Forward decl for stat/fstat. */
- struct stat;
- typedef struct host_callback_struct host_callback;
- struct host_callback_struct
- {
- int (*close) (host_callback *,int);
- int (*get_errno) (host_callback *);
- int (*isatty) (host_callback *, int);
- int64_t (*lseek) (host_callback *, int, int64_t, int);
- int (*open) (host_callback *, const char*, int mode);
- int (*read) (host_callback *,int, char *, int);
- int (*read_stdin) ( host_callback *, char *, int);
- int (*rename) (host_callback *, const char *, const char *);
- int (*system) (host_callback *, const char *);
- int64_t (*time) (host_callback *);
- int (*unlink) (host_callback *, const char *);
- int (*write) (host_callback *,int, const char *, int);
- int (*write_stdout) (host_callback *, const char *, int);
- void (*flush_stdout) (host_callback *);
- int (*write_stderr) (host_callback *, const char *, int);
- void (*flush_stderr) (host_callback *);
- int (*to_stat) (host_callback *, const char *, struct stat *);
- int (*to_fstat) (host_callback *, int, struct stat *);
- int (*to_lstat) (host_callback *, const char *, struct stat *);
- int (*ftruncate) (host_callback *, int, int64_t);
- int (*truncate) (host_callback *, const char *, int64_t);
- int (*getpid) (host_callback *);
- int (*kill) (host_callback *, int, int);
- int (*pipe) (host_callback *, int *);
- /* Called by the framework when a read call has emptied a pipe buffer. */
- void (*pipe_empty) (host_callback *, int read_fd, int write_fd);
- /* Called by the framework when a write call makes a pipe buffer
- non-empty. */
- void (*pipe_nonempty) (host_callback *, int read_fd, int write_fd);
- /* When present, call to the client to give it the oportunity to
- poll any io devices for a request to quit (indicated by a nonzero
- return value). */
- int (*poll_quit) (host_callback *);
- /* Used when the target has gone away, so we can close open
- handles and free memory etc etc. */
- int (*shutdown) (host_callback *);
- int (*init) (host_callback *);
- /* depreciated, use vprintf_filtered - Talk to the user on a console. */
- void (*printf_filtered) (host_callback *, const char *, ...)
- ATTRIBUTE_PRINTF_2;
- /* Talk to the user on a console. */
- void (*vprintf_filtered) (host_callback *, const char *, va_list)
- ATTRIBUTE_PRINTF (2, 0);
- /* Same as vprintf_filtered but to stderr. */
- void (*evprintf_filtered) (host_callback *, const char *, va_list)
- ATTRIBUTE_PRINTF (2, 0);
- /* Print an error message and "exit".
- In the case of gdb "exiting" means doing a longjmp back to the main
- command loop. */
- void (*error) (host_callback *, const char *, ...)
- ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_2;
- int last_errno; /* host format */
- int fdmap[MAX_CALLBACK_FDS];
- /* fd_buddy is used to contruct circular lists of target fds that point to
- the same host fd. A uniquely mapped fd points to itself; for a closed
- one, fd_buddy has the value -1. The host file descriptors for stdin /
- stdout / stderr are never closed by the simulators, so they are put
- in a special fd_buddy circular list which also has MAX_CALLBACK_FDS
- as a member. */
- /* ??? We don't have a callback entry for dup, although it is trival to
- implement now. */
- short fd_buddy[MAX_CALLBACK_FDS+1];
- /* 0 = none, >0 = reader (index of writer),
- <0 = writer (negative index of reader).
- If abs (ispipe[N]) == N, then N is an end of a pipe whose other
- end is closed. */
- short ispipe[MAX_CALLBACK_FDS];
- /* A writer stores the buffer at its index. Consecutive writes
- realloc the buffer and add to the size. The reader indicates the
- read part in its .size, until it has consumed it all, at which
- point it deallocates the buffer and zeroes out both sizes. */
- struct pipe_write_buffer
- {
- int size;
- char *buffer;
- } pipe_buffer[MAX_CALLBACK_FDS];
- /* System call numbers. */
- CB_TARGET_DEFS_MAP *syscall_map;
- /* Errno values. */
- CB_TARGET_DEFS_MAP *errno_map;
- /* Flags to the open system call. */
- CB_TARGET_DEFS_MAP *open_map;
- /* Signal numbers. */
- CB_TARGET_DEFS_MAP *signal_map;
- /* Layout of `stat' struct.
- The format is a series of "name,length" pairs separated by colons.
- Empty space is indicated with a `name' of "space".
- All padding must be explicitly mentioned.
- Lengths are in bytes. If this needs to be extended to bits,
- use "name.bits".
- Example: "st_dev,4:st_ino,4:st_mode,4:..." */
- const char *stat_map;
- enum bfd_endian target_endian;
- /* Program command line options. */
- char **argv;
- /* Program environment. */
- char **envp;
- /* Size of an "int" on the target (for syscalls whose ABI uses "int").
- This must include padding, and only padding-at-higher-address is
- supported. For example, a 64-bit target with 32-bit int:s which
- are padded to 64 bits when in an array, should supposedly set this
- to 8. The default is 4 which matches ILP32 targets and 64-bit
- targets with 32-bit ints and no padding. */
- int target_sizeof_int;
- /* Marker for those wanting to do sanity checks.
- This should remain the last member of this struct to help catch
- miscompilation errors. */
- #define HOST_CALLBACK_MAGIC 4705 /* teds constant */
- int magic;
- };
- extern host_callback default_callback;
- /* Canonical versions of system call numbers.
- It's not intended to willy-nilly throw every system call ever heard
- of in here. Only include those that have an important use.
- ??? One can certainly start a discussion over the ones that are currently
- here, but that will always be true. */
- /* These are used by the ANSI C support of libc. */
- #define CB_SYS_exit 1
- #define CB_SYS_open 2
- #define CB_SYS_close 3
- #define CB_SYS_read 4
- #define CB_SYS_write 5
- #define CB_SYS_lseek 6
- #define CB_SYS_unlink 7
- #define CB_SYS_getpid 8
- #define CB_SYS_kill 9
- #define CB_SYS_fstat 10
- /*#define CB_SYS_sbrk 11 - not currently a system call, but reserved. */
- /* ARGV support. */
- #define CB_SYS_argvlen 12
- #define CB_SYS_argv 13
- /* These are extras added for one reason or another. */
- #define CB_SYS_chdir 14
- #define CB_SYS_stat 15
- #define CB_SYS_chmod 16
- #define CB_SYS_utime 17
- #define CB_SYS_time 18
- /* More standard syscalls. */
- #define CB_SYS_lstat 19
- #define CB_SYS_rename 20
- #define CB_SYS_truncate 21
- #define CB_SYS_ftruncate 22
- #define CB_SYS_pipe 23
- /* New ARGV support. */
- #define CB_SYS_argc 24
- #define CB_SYS_argnlen 25
- #define CB_SYS_argn 26
- /* Struct use to pass and return information necessary to perform a
- system call. */
- /* FIXME: Need to consider target word size. */
- typedef struct cb_syscall {
- /* The target's value of what system call to perform. */
- int func;
- /* The arguments to the syscall. */
- long arg1, arg2, arg3, arg4, arg5, arg6, arg7;
- /* The result. */
- long result;
- /* Some system calls have two results. */
- long result2;
- /* The target's errno value, or 0 if success.
- This is converted to the target's value with host_to_target_errno. */
- int errcode;
- /* Working space to be used by memory read/write callbacks. */
- void *p1;
- void *p2;
- long x1,x2;
- /* Callbacks for reading/writing memory (e.g. for read/write syscalls).
- ??? long or unsigned long might be better to use for the `count'
- argument here. We mimic sim_{read,write} for now. Be careful to
- test any changes with -Wall -Werror, mixed signed comparisons
- will get you. */
- int (*read_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/,
- unsigned long /*taddr*/, char * /*buf*/,
- int /*bytes*/);
- int (*write_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/,
- unsigned long /*taddr*/, const char * /*buf*/,
- int /*bytes*/);
- /* For sanity checking, should be last entry. */
- int magic;
- } CB_SYSCALL;
- /* Magic number sanity checker. */
- #define CB_SYSCALL_MAGIC 0x12344321
- /* Macro to initialize CB_SYSCALL. Called first, before filling in
- any fields. */
- #define CB_SYSCALL_INIT(sc) \
- do { \
- memset ((sc), 0, sizeof (*(sc))); \
- (sc)->magic = CB_SYSCALL_MAGIC; \
- } while (0)
- /* Return codes for various interface routines. */
- typedef enum {
- CB_RC_OK = 0,
- /* generic error */
- CB_RC_ERR,
- /* either file not found or no read access */
- CB_RC_ACCESS,
- CB_RC_NO_MEM
- } CB_RC;
- /* Read in target values for system call numbers, errno values, signals. */
- CB_RC cb_read_target_syscall_maps (host_callback *, const char *);
- /* Translate target to host syscall function numbers. */
- int cb_target_to_host_syscall (host_callback *, int);
- /* Translate host to target errno value. */
- int cb_host_to_target_errno (host_callback *, int);
- /* Translate target to host open flags. */
- int cb_target_to_host_open (host_callback *, int);
- /* Translate target signal number to host. */
- int cb_target_to_host_signal (host_callback *, int);
- /* Translate host signal number to target. */
- int cb_host_to_gdb_signal (host_callback *, int);
- /* Translate symbols into human readable strings. */
- const char *cb_host_str_syscall (host_callback *, int);
- const char *cb_host_str_errno (host_callback *, int);
- const char *cb_host_str_signal (host_callback *, int);
- const char *cb_target_str_syscall (host_callback *, int);
- const char *cb_target_str_errno (host_callback *, int);
- const char *cb_target_str_signal (host_callback *, int);
- /* Translate host stat struct to target.
- If stat struct ptr is NULL, just compute target stat struct size.
- Result is size of target stat struct or 0 if error. */
- int cb_host_to_target_stat (host_callback *, const struct stat *, void *);
- /* Translate a value to target endian. */
- void cb_store_target_endian (host_callback *, char *, int, long);
- /* Tests for special fds. */
- int cb_is_stdin (host_callback *, int);
- int cb_is_stdout (host_callback *, int);
- int cb_is_stderr (host_callback *, int);
- /* Read a string out of the target. */
- int cb_get_string (host_callback *, CB_SYSCALL *, char *, int, unsigned long);
- /* Perform a system call. */
- CB_RC cb_syscall (host_callback *, CB_SYSCALL *);
- #endif
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