323 lines
12 KiB
C
323 lines
12 KiB
C
/* Remote target system call callback support.
|
||
Copyright 1997 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 2 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, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
||
|
||
/* 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 CALLBACK_H
|
||
#define CALLBACK_H
|
||
|
||
/* ??? The reason why we check for va_start here should be documented. */
|
||
|
||
#ifndef va_start
|
||
#include <ansidecl.h>
|
||
#include <stdarg.h>
|
||
#endif
|
||
/* 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 {
|
||
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) PARAMS ((host_callback *,int));
|
||
int (*get_errno) PARAMS ((host_callback *));
|
||
int (*isatty) PARAMS ((host_callback *, int));
|
||
int (*lseek) PARAMS ((host_callback *, int, long , int));
|
||
int (*open) PARAMS ((host_callback *, const char*, int mode));
|
||
int (*read) PARAMS ((host_callback *,int, char *, int));
|
||
int (*read_stdin) PARAMS (( host_callback *, char *, int));
|
||
int (*rename) PARAMS ((host_callback *, const char *, const char *));
|
||
int (*system) PARAMS ((host_callback *, const char *));
|
||
long (*time) PARAMS ((host_callback *, long *));
|
||
int (*unlink) PARAMS ((host_callback *, const char *));
|
||
int (*write) PARAMS ((host_callback *,int, const char *, int));
|
||
int (*write_stdout) PARAMS ((host_callback *, const char *, int));
|
||
void (*flush_stdout) PARAMS ((host_callback *));
|
||
int (*write_stderr) PARAMS ((host_callback *, const char *, int));
|
||
void (*flush_stderr) PARAMS ((host_callback *));
|
||
int (*stat) PARAMS ((host_callback *, const char *, struct stat *));
|
||
int (*fstat) PARAMS ((host_callback *, int, struct stat *));
|
||
int (*lstat) PARAMS ((host_callback *, const char *, struct stat *));
|
||
int (*ftruncate) PARAMS ((host_callback *, int, long));
|
||
int (*truncate) PARAMS ((host_callback *, const char *, long));
|
||
int (*pipe) PARAMS ((host_callback *, int *));
|
||
|
||
/* Called by the framework when a read call has emptied a pipe buffer. */
|
||
void (*pipe_empty) PARAMS ((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) PARAMS ((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) PARAMS ((host_callback *));
|
||
|
||
/* Used when the target has gone away, so we can close open
|
||
handles and free memory etc etc. */
|
||
int (*shutdown) PARAMS ((host_callback *));
|
||
int (*init) PARAMS ((host_callback *));
|
||
|
||
/* depreciated, use vprintf_filtered - Talk to the user on a console. */
|
||
void (*printf_filtered) PARAMS ((host_callback *, const char *, ...));
|
||
|
||
/* Talk to the user on a console. */
|
||
void (*vprintf_filtered) PARAMS ((host_callback *, const char *, va_list));
|
||
|
||
/* Same as vprintf_filtered but to stderr. */
|
||
void (*evprintf_filtered) PARAMS ((host_callback *, const char *, va_list));
|
||
|
||
/* Print an error message and "exit".
|
||
In the case of gdb "exiting" means doing a longjmp back to the main
|
||
command loop. */
|
||
void (*error) PARAMS ((host_callback *, const char *, ...));
|
||
|
||
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;
|
||
|
||
/* 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
|
||
|
||
/* 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;
|
||
|
||
/* 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. */
|
||
PTR p1;
|
||
PTR 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) PARAMS ((host_callback * /*cb*/, struct cb_syscall * /*sc*/,
|
||
unsigned long /*taddr*/, char * /*buf*/,
|
||
int /*bytes*/));
|
||
int (*write_mem) PARAMS ((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 PARAMS ((host_callback *, const char *));
|
||
|
||
/* Translate target to host syscall function numbers. */
|
||
int cb_target_to_host_syscall PARAMS ((host_callback *, int));
|
||
|
||
/* Translate host to target errno value. */
|
||
int cb_host_to_target_errno PARAMS ((host_callback *, int));
|
||
|
||
/* Translate target to host open flags. */
|
||
int cb_target_to_host_open PARAMS ((host_callback *, int));
|
||
|
||
/* Translate target signal number to host. */
|
||
int cb_target_to_host_signal PARAMS ((host_callback *, int));
|
||
|
||
/* Translate host signal number to target. */
|
||
int cb_host_to_target_signal PARAMS ((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 PARAMS ((host_callback *, const struct stat *, PTR));
|
||
|
||
/* Translate a value to target endian. */
|
||
void cb_store_target_endian PARAMS ((host_callback *, char *, int, long));
|
||
|
||
/* Perform a system call. */
|
||
CB_RC cb_syscall PARAMS ((host_callback *, CB_SYSCALL *));
|
||
|
||
#endif
|