binutils-gdb/gdb/ser-go32.c
Steve Chamberlain be5e6fff5a Work to reduce the interrupts-off duration when running in DOS.
* ser-go32.c:  (dos_async_ready): See if anything is in the buffer.
	(dos_async_rx): rewrite to unpack as many characters from the
	asynctsr as possible into a local buffer.
1994-08-22 17:58:47 +00:00

479 lines
9.1 KiB
C

/* Remote serial interface for local (hardwired) serial ports for GO32.
Copyright 1992, 1993 Free Software Foundation, Inc.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "defs.h"
#include "serial.h"
#include <sys/dos.h>
#define disable() asm("cli")
#define enable() asm("sti")
struct go32_ttystate
{
int bogus;
};
typedef struct
{
short jmp_op;
short signature;
short version;
short buffer_start;
short buffer_end;
short getp;
short putp;
short iov;
short count;
short overflow;
short buffer_size;
short ovflushes;
}
ASYNC_STRUCT;
#define AOFF_JMP_OP 0
#define AOFF_SIGNATURE 2
#define AOFF_VERSION 4
#define AOFF_BUFFER_START 6
#define AOFF_BUFFER_END 8
#define AOFF_GETP 10
#define AOFF_PUTP 12
#define AOFF_IOV 14
#define AOFF_COUNT 16
#define AOFF_OVERFLOW 18
#define AOFF_BUFFER_SIZE 20
#define AOFF_OVFLUSHES 22
static ASYNC_STRUCT a; /* Copy in our mem of the struct */
static long aindex; /* index into dos space of struct */
static int go32_open PARAMS ((serial_t scb, const char *name));
static void go32_raw PARAMS ((serial_t scb));
static int go32_readchar PARAMS ((serial_t scb, int timeout));
static int go32_setbaudrate PARAMS ((serial_t scb, int rate));
static int go32_write PARAMS ((serial_t scb, const char *str, int len));
static void go32_close PARAMS ((serial_t scb));
static serial_ttystate go32_get_tty_state PARAMS ((serial_t scb));
static int go32_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
static unsigned char aptr PARAMS ((short p));
static unsigned long getivec PARAMS ((int which));
static int dos_async_init PARAMS ((int port));
static void dos_async_tx PARAMS ((const char c));
static int dos_async_rx PARAMS (());
static int dosasync_read PARAMS ((int fd, char *buf, int len, int timeout));
static int dosasync_write PARAMS ((int fd, const char *buf, int len));
#define SIGNATURE 0x4154
#define VERSION 1
#define OFFSET 0x104
char packet[50];
int packet_len;
int packet_idx;
unsigned char bb;
unsigned short sb;
unsigned long sl;
#define SET_BYTE(x,y) { char _buf = y;dosmemput(&_buf,1, x);}
#define SET_WORD(x,y) { short _buf = y;dosmemput(&_buf,2, x);}
#define GET_BYTE(x) ( dosmemget((x),1,&bb), bb)
#define GET_LONG(x) ( dosmemget((x),4,&sl), sl)
static
unsigned short
GET_WORD (x)
{
unsigned short sb;
dosmemget ((x), 2, &sb);
return sb;
}
static int iov[2];
#define com_rb(n) iov[n]
#define com_tb(n) iov[n]
#define com_ier(n) iov[n]+1
#define com_ifr(n) iov[n]+2
#define com_bfr(n) iov[n]+3
#define com_mcr(n) iov[n]+4
#define com_lsr(n) iov[n]+5
#define com_msr(n) iov[n]+6
static unsigned char
aptr (p)
short p;
{
return GET_BYTE (aindex - OFFSET + p);
}
static unsigned long
getivec (int which)
{
long tryaindex;
if (GET_WORD (which * 4) != OFFSET)
return 0;
/* Find out where in memory this lives */
tryaindex = GET_WORD (which * 4 + 2) * 16 + GET_WORD (which * 4);
if (GET_WORD (tryaindex + 2) != SIGNATURE)
return 0;
if (GET_WORD (tryaindex + 4) != VERSION)
return 0;
return tryaindex;
}
static int
dos_async_init (port)
int port;
{
switch (port)
{
case 1:
aindex = getivec (12);
break;
case 2:
aindex = getivec (11);
break;
default:
return 0;
}
if (!aindex)
{
error ("GDB cannot connect to asynctsr program, check that it is installed\n\
and that serial I/O is not being redirected (perhaps by NFS)\n\n\
example configuration:\n\
C> mode com%d:9600,n,8,1,p\n\
C> asynctsr %d\n\
C> gdb \n", port, port);
}
iov[0] = GET_WORD (aindex + AOFF_IOV);
outportb (com_ier (0), 0x0f);
outportb (com_bfr (0), 0x03);
outportb (com_mcr (0), 0x0b);
return 1;
}
static void
dos_async_tx (c)
const char c;
{
while (~inportb (com_lsr (0)) & 0x20)
;
outportb (com_tb (0), c);
}
static int
dos_async_ready ()
{
int ret;
if (packet_idx < packet_len)
return 1;
disable ();
#if RDY_CNT
ret = GET_WORD (aindex + AOFF_COUNT);
#else
ret = GET_WORD (aindex + AOFF_GETP) != GET_WORD (aindex + AOFF_PUTP);
#endif
enable ();
return ret;
}
static int
dos_async_rx ()
{
char rv;
short idx;
while (1)
{
if (packet_idx < packet_len)
{
char x = packet[packet_idx++];
return x;
}
while (!dos_async_ready ())
{
if (kbhit ())
{
printf_unfiltered ("abort!\n");
return 0;
}
}
disable ();
{
/* Sometimes we can read more than one char at a time
from the buffer, which is good, cause it'll mean
less time with interrupts turned off, which means
less dropped characters */
/* We only do the simplest case here - not bothering with
wrap around */
int len;
int getp = GET_WORD (aindex + AOFF_GETP);
int putp = GET_WORD (aindex + AOFF_PUTP);
int endb = GET_WORD (aindex + AOFF_BUFFER_END);
int startb = GET_WORD (aindex + AOFF_BUFFER_START);
/* We'd like to grab to the end of the the input,
but it may have wrapped, so max is to the end
of the buffer */
if (putp > endb || putp < getp)
putp = endb;
/* Work out the length of the suck */
len = putp - getp;
/* But only suck as many as we can hold in one go */
if (len > sizeof (packet))
len = sizeof (packet);
dosmemget (aindex - OFFSET + getp, len, packet);
packet_len = len;
packet_idx = 0;
if (getp + len >= endb)
{
getp = startb;
}
else
{
getp = getp + len;
}
SET_WORD (aindex + AOFF_GETP, getp);
SET_WORD (aindex + AOFF_COUNT, GET_WORD (aindex + AOFF_COUNT) - len);
}
enable ();
}
}
static int
dosasync_read (fd, buf, len, timeout)
int fd;
char *buf;
int len;
int timeout;
{
long now, then;
int i;
int its = 0;
time (&now);
then = now + timeout;
for (i = 0; i < len; i++)
{
if (timeout)
{
while (!dos_async_ready ())
{
time (&now);
if (now >= then && timeout > 0 && its > 1000)
return i;
its++;
}
}
*buf++ = dos_async_rx ();
}
return len;
}
static int
dosasync_write (fd, buf, len)
int fd;
const char *buf;
int len;
{
int l;
for (l = 0; l < len; l++)
dos_async_tx (*buf++);
return len;
}
static int
go32_open (scb, name)
serial_t scb;
const char *name;
{
int port;
if (strncasecmp (name, "com", 3) != 0)
{
errno = ENOENT;
return -1;
}
port = name[3] - '0';
if ((port != 1) && (port != 2))
{
errno = ENOENT;
return -11;
}
scb->fd = dos_async_init (port);
if (!scb->fd)
return -1;
return 0;
}
static int
go32_noop (scb)
serial_t scb;
{
return 0;
}
static void
go32_raw (scb)
serial_t scb;
{
/* Always in raw mode */
}
static int
go32_readchar (scb, timeout)
serial_t scb;
int timeout;
{
char buf;
/* Shortcut for polling */
if (timeout == 0)
{
if (dos_async_ready ())
{
return dos_async_rx ();
}
return SERIAL_TIMEOUT;
}
if (dosasync_read (scb->fd, &buf, 1, timeout))
return buf;
else
return SERIAL_TIMEOUT;
}
/* go32_{get set}_tty_state() are both dummys to fill out the function
vector. Someday, they may do something real... */
static serial_ttystate
go32_get_tty_state (scb)
serial_t scb;
{
struct go32_ttystate *state;
state = (struct go32_ttystate *) xmalloc (sizeof *state);
return (serial_ttystate) state;
}
static int
go32_set_tty_state (scb, ttystate)
serial_t scb;
serial_ttystate ttystate;
{
return 0;
}
static int
go32_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
serial_t scb;
serial_ttystate new_ttystate;
serial_ttystate old_ttystate;
{
return 0;
}
static void
go32_print_tty_state (scb, ttystate)
serial_t scb;
serial_ttystate ttystate;
{
/* Nothing to print. */
return;
}
static int
go32_setbaudrate (scb, rate)
serial_t scb;
int rate;
{
return 0;
}
static int
go32_write (scb, str, len)
serial_t scb;
const char *str;
int len;
{
dosasync_write (scb->fd, str, len);
return 0;
}
static void
go32_close (scb)
serial_t scb;
{
}
static struct serial_ops go32_ops =
{
"hardwire",
0,
go32_open,
go32_close,
go32_readchar,
go32_write,
go32_noop, /* flush output */
go32_noop, /* flush input */
go32_noop, /* send break -- currently used only for nindy */
go32_raw,
go32_get_tty_state,
go32_set_tty_state,
go32_print_tty_state,
go32_noflush_set_tty_state,
go32_setbaudrate,
};
void
_initialize_ser_go32 ()
{
serial_add_interface (&go32_ops);
}