-/* Remote target communications for serial-line targets in custom GDB protocol
- Copyright 1988, 1991, 1992 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. */
-
-/* Remote communication protocol.
- All values are encoded in ascii hex digits.
-
- Request Packet
-
- read registers g
- reply XX....X Each byte of register data
- is described by two hex digits.
- Registers are in the internal order
- for GDB, and the bytes in a register
- are in the same order the machine uses.
- or ENN for an error.
-
- write regs GXX..XX Each byte of register data
- is described by two hex digits.
- reply OK for success
- ENN for an error
-
- read mem mAA..AA,LLLL AA..AA is address, LLLL is length.
- reply XX..XX XX..XX is mem contents
- or ENN NN is errno
-
- write mem MAA..AA,LLLL:XX..XX
- AA..AA is address,
- LLLL is number of bytes,
- XX..XX is data
- reply OK for success
- ENN for an error
-
- cont cAA..AA AA..AA is address to resume
- If AA..AA is omitted,
- resume at same address.
-
- step sAA..AA AA..AA is address to resume
- If AA..AA is omitted,
- resume at same address.
-
- last signal ? Reply the current reason for stopping.
- This is the same reply as is generated
- for step or cont : SAA where AA is the
- signal number.
-
- There is no immediate reply to step or cont.
- The reply comes when the machine stops.
- It is SAA AA is the "signal number"
-
- or... TAAPPPPPPPPFFFFFFFF
- where AA is the signal number,
- PPPPPPPP is the PC (PC_REGNUM), and
- FFFFFFFF is the frame ptr (FP_REGNUM).
-
- kill req k
-*/
-
-#include "defs.h"
-#include <string.h>
-#include "serial.h"
-#include "frame.h"
-#include "inferior.h"
-#include "target.h"
-#include "wait.h"
-#include "terminal.h"
-#include "gdbcmd.h"
-
-#include <signal.h>
-
-static int kiodebug = 0;
-static int timeout = 5;
-
-#define PBUFSIZ 1024
-
-/* Maximum number of bytes to read/write at once. The value here
- is chosen to fill up a packet (the headers account for the 32). */
-#define MAXBUFBYTES ((PBUFSIZ-32)/2)
-
-/* Round up PBUFSIZ to hold all the registers, at least. */
-#if REGISTER_BYTES > MAXBUFBYTES
-#undef PBUFSIZ
-#define PBUFSIZ (REGISTER_BYTES * 2 + 32)
-#endif
-\f
-/* remote_detach()
- takes a program previously attached to and detaches it.
- We better not have left any breakpoints
- in the program or it'll die when it hits one.
- Close the open connection to the remote debugger.
- Use this when you want to detach and do something else
- with your gdb. */
-
-static void
-remote_detach (args, from_tty)
- char *args;
- int from_tty;
-{
- if (args)
- error ("Argument given to \"detach\" when remotely debugging.");
-
- pop_target ();
- if (from_tty)
- printf ("Ending remote debugging.\n");
-}
-
-/* Convert hex digit A to a number. */
-
-static int
-fromhex (a)
- int a;
-{
- if (a >= '0' && a <= '9')
- return a - '0';
- else if (a >= 'a' && a <= 'f')
- return a - 'a' + 10;
- else
- error ("Reply contains invalid hex digit");
- return -1;
-}
-
-/* Convert number NIB to a hex digit. */
-
-static int
-tohex (nib)
- int nib;
-{
- if (nib < 10)
- return '0'+nib;
- else
- return 'a'+nib-10;
-}
-\f
-/* Tell the remote machine to resume. */
-
-/* Send a packet to the remote machine, with error checking.
- The data of the packet is in BUF. */
-
-static void
-putpkt (buf)
- char *buf;
-{
- int i;
- unsigned char csum = 0;
- char buf2[PBUFSIZ];
- int cnt = strlen (buf);
- char ch;
- char *p;
-
- /* Copy the packet into buffer BUF2, encapsulating it
- and giving it a checksum. */
-
- if (cnt > sizeof(buf2) - 5) /* Prosanity check */
- abort();
-
- p = buf2;
- *p++ = '$';
-
- for (i = 0; i < cnt; i++)
- {
- csum += buf[i];
- *p++ = buf[i];
- }
- *p++ = '#';
- *p++ = tohex ((csum >> 4) & 0xf);
- *p++ = tohex (csum & 0xf);
-
- /* Send it over and over until we get a positive ack. */
-
- do {
- if (kiodebug)
- {
- *p = '\0';
- printf ("Sending packet: %s...", buf2); fflush(stdout);
- }
- serial_write (buf2, p - buf2);
-
- /* read until either a timeout occurs (\0) or '+' is read */
- do {
- ch = readchar ();
- if (kiodebug) {
- if (ch == '+')
- printf("Ack\n");
- else
- printf ("%02X%c ", ch&0xFF, ch);
- }
- } while ((ch != '+') && (ch != '\0'));
- } while (ch != '+');
-}
-
-/* Read a packet from the remote machine, with error checking,
- and store it in BUF. BUF is expected to be of size PBUFSIZ. */
-
-static void
-getpkt (buf)
- char *buf;
-{
- char *bp;
- unsigned char csum;
- int c;
- unsigned char c1, c2;
-
- while (1)
- {
- /* Force csum to be zero here because of possible error retry. */
- csum = 0;
-
- while ((c = readchar()) != '$');
-
- bp = buf;
- while (1)
- {
- c = readchar ();
- if (c == '#')
- break;
- if (bp >= buf+PBUFSIZ-1)
- {
- *bp = '\0';
- printf_filtered ("Remote packet too long: %s\n", buf);
- goto whole;
- }
- *bp++ = c;
- csum += c;
- }
- *bp = 0;
-
- c1 = fromhex (readchar ());
- c2 = fromhex (readchar ());
- if ((csum & 0xff) == (c1 << 4) + c2)
- break;
- printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=%s\n",
- (c1 << 4) + c2, csum & 0xff, buf);
- /* Try the whole thing again. */
-whole:
- serial_write ("-", 1);
- }
-
-#if 0
- immediate_quit--;
-#endif
-
- serial_write ("+", 1);
-
- if (kiodebug)
- fprintf (stderr,"Packet received: %s\n", buf);
-}
-
-static void
-remote_resume (step, siggnal)
- int step, siggnal;
-{
- char buf[PBUFSIZ];
-
- if (siggnal)
- error ("Can't send signals to a remote system. Try `handle %d ignore'.",
- siggnal);
-
-#if 0
- dcache_flush ();
-#endif
-
- strcpy (buf, step ? "s": "c");
-
- putpkt (buf);
-}
-
-/* Send ^C to target to halt it. Target will respond, and send us a
- packet. */
-
-void remote_interrupt(signo)
- int signo;
-{
-
- if (kiodebug)
- printf ("remote_interrupt called\n");
-
- serial_write ("\003", 1); /* Send a ^C */
-}
-
-
-/* Wait until the remote machine stops, then return,
- storing status in STATUS just as `wait' would.
- Returns "pid" (though it's not clear what, if anything, that
- means in the case of this target). */
-
-static int
-remote_wait (status)
- WAITTYPE *status;
-{
- unsigned char buf[PBUFSIZ];
- void (*ofunc)();
- unsigned char *p;
- int i;
- char regs[REGISTER_RAW_SIZE (PC_REGNUM) + REGISTER_RAW_SIZE (FP_REGNUM)];
-
- WSETEXIT ((*status), 0);
-
- ofunc = (void (*)()) signal (SIGINT, remote_interrupt);
- getpkt ((char *) buf);
- signal (SIGINT, ofunc);
-
- if (buf[0] == 'E')
- error ("Remote failure reply: %s", buf);
- if (buf[0] == 'T')
- {
- /* Expedited reply, containing Signal, PC, and FP. */
- p = &buf[3]; /* after Txx */
- for (i = 0; i < sizeof (regs); i++)
- {
- if (p[0] == 0 || p[1] == 0)
- error ("Remote reply is too short: %s", buf);
- regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
- p += 2;
- }
- supply_register (PC_REGNUM, ®s[0]);
- supply_register (FP_REGNUM, ®s[REGISTER_RAW_SIZE (PC_REGNUM)]);
- }
- else if (buf[0] != 'S')
- error ("Invalid remote reply: %s", buf);
-
- WSETSTOP ((*status), (((fromhex (buf[1])) << 4) + (fromhex (buf[2]))));
-
- return 0;
-}
-
-/* Send the command in BUF to the remote machine,
- and read the reply into BUF.
- Report an error if we get an error reply. */
-
-static void
-remote_send (buf)
- char *buf;
-{
-
- putpkt (buf);
- getpkt (buf);
-
- if (buf[0] == 'E')
- error ("Remote failure reply: %s", buf);
-}
-
-/* Read the remote registers into the block REGS. */
-/* Currently we just read all the registers, so we don't use regno. */
-/* ARGSUSED */
-static void
-remote_fetch_registers (regno)
- int regno;
-{
- char buf[PBUFSIZ];
- int i;
- char *p;
- char regs[REGISTER_BYTES];
-
- sprintf (buf, "g");
- remote_send (buf);
-
- /* Reply describes registers byte by byte, each byte encoded as two
- hex characters. Suck them all up, then supply them to the
- register cacheing/storage mechanism. */
-
- p = buf;
- for (i = 0; i < REGISTER_BYTES; i++)
- {
- if (p[0] == 0 || p[1] == 0)
- error ("Remote reply is too short: %s", buf);
- regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
- p += 2;
- }
- for (i = 0; i < NUM_REGS; i++)
- supply_register (i, ®s[REGISTER_BYTE(i)]);
-}
-
-/* Prepare to store registers. Since we send them all, we have to
- read out the ones we don't want to change first. */
-
-static void
-remote_prepare_to_store ()
-{
- remote_fetch_registers (-1);
-}
-
-/* Store the remote registers from the contents of the block REGISTERS.
- FIXME, eventually just store one register if that's all that is needed. */
-
-/* ARGSUSED */
-static void
-remote_store_registers (regno)
- int regno;
-{
- char buf[PBUFSIZ];
- int i;
- char *p;
-
- buf[0] = 'G';
-
- /* Command describes registers byte by byte,
- each byte encoded as two hex characters. */
-
- p = buf + 1;
- for (i = 0; i < REGISTER_BYTES; i++)
- {
- *p++ = tohex ((registers[i] >> 4) & 0xf);
- *p++ = tohex (registers[i] & 0xf);
- }
- *p = '\0';
-
- remote_send (buf);
-}
-
-\f
-/* Write memory data directly to the remote machine.
- This does not inform the data cache; the data cache uses this.
- MEMADDR is the address in the remote memory space.
- MYADDR is the address of the buffer in our space.
- LEN is the number of bytes. */
-
-static void
-remote_write_bytes (memaddr, myaddr, len)
- CORE_ADDR memaddr;
- char *myaddr;
- int len;
-{
- char buf[PBUFSIZ];
- int i;
- char *p;
-
- if (len > PBUFSIZ / 2 - 20)
- abort ();
-
- sprintf (buf, "M%x,%x:", memaddr, len);
-
- /* We send target system values byte by byte, in increasing byte addresses,
- each byte encoded as two hex characters. */
-
- p = buf + strlen (buf);
- for (i = 0; i < len; i++)
- {
- *p++ = tohex ((myaddr[i] >> 4) & 0xf);
- *p++ = tohex (myaddr[i] & 0xf);
- }
- *p = '\0';
-
- remote_send (buf);
-}
-
-/* Read memory data directly from the remote machine.
- This does not use the data cache; the data cache uses this.
- MEMADDR is the address in the remote memory space.
- MYADDR is the address of the buffer in our space.
- LEN is the number of bytes. */
-
-static void
-remote_read_bytes (memaddr, myaddr, len)
- CORE_ADDR memaddr;
- char *myaddr;
- int len;
-{
- char buf[PBUFSIZ];
- int i;
- char *p;
-
- if (len > PBUFSIZ / 2 - 1)
- abort ();
-
- sprintf (buf, "m%x,%x", memaddr, len);
- remote_send (buf);
-
- /* Reply describes memory byte by byte,
- each byte encoded as two hex characters. */
-
- p = buf;
- for (i = 0; i < len; i++)
- {
- if (p[0] == 0 || p[1] == 0)
- error ("Remote reply is too short: %s", buf);
- myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
- p += 2;
- }
-}
-\f
-/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
- to or from debugger address MYADDR. Write to inferior if SHOULD_WRITE is
- nonzero. Returns length of data written or read; 0 for error. */
-
-/* ARGSUSED */
-static int
-remote_xfer_memory(memaddr, myaddr, len, should_write, target)
- CORE_ADDR memaddr;
- char *myaddr;
- int len;
- int should_write;
- struct target_ops *target; /* ignored */
-{
- int origlen = len;
- int xfersize;
- while (len > 0)
- {
- if (len > MAXBUFBYTES)
- xfersize = MAXBUFBYTES;
- else
- xfersize = len;
-
- if (should_write)
- remote_write_bytes(memaddr, myaddr, xfersize);
- else
- remote_read_bytes (memaddr, myaddr, xfersize);
- memaddr += xfersize;
- myaddr += xfersize;
- len -= xfersize;
- }
- return origlen; /* no error possible */
-}
-
-static void
-remote_files_info (ignore)
-struct target_ops *ignore;
-{
- printf ("Debugging a target over a serial line.\n");
-}
-\f
-/*
-
-A debug packet whose contents are <data>
-is encapsulated for transmission in the form:
-
- $ <data> # CSUM1 CSUM2
-
- <data> must be ASCII alphanumeric and cannot include characters
- '$' or '#'
-
- CSUM1 and CSUM2 are ascii hex representation of an 8-bit
- checksum of <data>, the most significant nibble is sent first.
- the hex digits 0-9,a-f are used.
-
-Receiver responds with:
-
- + - if CSUM is correct and ready for next packet
- - - if CSUM is incorrect
-
-*/
-
-/* Read a single character from the remote end.
- (If supported, we actually read many characters and buffer them up.) */
-
-static int
-readchar ()
-{
- static int inbuf_index, inbuf_count;
-#define INBUFSIZE PBUFSIZ
- static char inbuf[INBUFSIZE];
-
- if (inbuf_index >= inbuf_count)
- {
- /* Time to do another read... */
- inbuf_index = 0;
- inbuf_count = 0;
- inbuf[0] = 0; /* Just in case */
- if ((inbuf[inbuf_index] = serial_readchar (timeout)) < 0)
- inbuf_count = -1;
- else
- inbuf_count = 1;
- }
-
- /* Just return the next character from the buffer. */
- return inbuf[inbuf_index++] & 0x7f;
-}
-
-
-\f
-/* The data cache leads to incorrect results because it doesn't know about
- volatile variables, thus making it impossible to debug functions which
- use hardware registers. Therefore it is #if 0'd out. Effect on
- performance is some, for backtraces of functions with a few
- arguments each. For functions with many arguments, the stack
- frames don't fit in the cache blocks, which makes the cache less
- helpful. Disabling the cache is a big performance win for fetching
- large structures, because the cache code fetched data in 16-byte
- chunks. */
-#if 0
-/* The data cache records all the data read from the remote machine
- since the last time it stopped.
-
- Each cache block holds 16 bytes of data
- starting at a multiple-of-16 address. */
-
-#define DCACHE_SIZE 64 /* Number of cache blocks */
-
-struct dcache_block {
- struct dcache_block *next, *last;
- unsigned int addr; /* Address for which data is recorded. */
- int data[4];
-};
-
-struct dcache_block dcache_free, dcache_valid;
-
-/* Free all the data cache blocks, thus discarding all cached data. */
-
-static void
-dcache_flush ()
-{
- register struct dcache_block *db;
-
- while ((db = dcache_valid.next) != &dcache_valid)
- {
- remque (db);
- insque (db, &dcache_free);
- }
-}
-
-/*
- * If addr is present in the dcache, return the address of the block
- * containing it.
- */
-
-struct dcache_block *
-dcache_hit (addr)
-{
- register struct dcache_block *db;
-
- if (addr & 3)
- abort ();
-
- /* Search all cache blocks for one that is at this address. */
- db = dcache_valid.next;
- while (db != &dcache_valid)
- {
- if ((addr & 0xfffffff0) == db->addr)
- return db;
- db = db->next;
- }
- return NULL;
-}
-
-/* Return the int data at address ADDR in dcache block DC. */
-
-int
-dcache_value (db, addr)
- struct dcache_block *db;
- unsigned int addr;
-{
- if (addr & 3)
- abort ();
- return (db->data[(addr>>2)&3]);
-}
-
-/* Get a free cache block, put it on the valid list,
- and return its address. The caller should store into the block
- the address and data that it describes. */
-
-struct dcache_block *
-dcache_alloc ()
-{
- register struct dcache_block *db;
-
- if ((db = dcache_free.next) == &dcache_free)
- /* If we can't get one from the free list, take last valid */
- db = dcache_valid.last;
-
- remque (db);
- insque (db, &dcache_valid);
- return (db);
-}
-
-/* Return the contents of the word at address ADDR in the remote machine,
- using the data cache. */
-
-int
-dcache_fetch (addr)
- CORE_ADDR addr;
-{
- register struct dcache_block *db;
-
- db = dcache_hit (addr);
- if (db == 0)
- {
- db = dcache_alloc ();
- remote_read_bytes (addr & ~0xf, db->data, 16);
- db->addr = addr & ~0xf;
- }
- return (dcache_value (db, addr));
-}
-
-/* Write the word at ADDR both in the data cache and in the remote machine. */
-
-dcache_poke (addr, data)
- CORE_ADDR addr;
- int data;
-{
- register struct dcache_block *db;
-
- /* First make sure the word is IN the cache. DB is its cache block. */
- db = dcache_hit (addr);
- if (db == 0)
- {
- db = dcache_alloc ();
- remote_read_bytes (addr & ~0xf, db->data, 16);
- db->addr = addr & ~0xf;
- }
-
- /* Modify the word in the cache. */
- db->data[(addr>>2)&3] = data;
-
- /* Send the changed word. */
- remote_write_bytes (addr, &data, 4);
-}
-
-/* Initialize the data cache. */
-
-dcache_init ()
-{
- register i;
- register struct dcache_block *db;
-
- db = (struct dcache_block *) xmalloc (sizeof (struct dcache_block) *
- DCACHE_SIZE);
- dcache_free.next = dcache_free.last = &dcache_free;
- dcache_valid.next = dcache_valid.last = &dcache_valid;
- for (i=0;i<DCACHE_SIZE;i++,db++)
- insque (db, &dcache_free);
-}
-#endif /* 0 */
-
-/* Define the target subroutine names */
-
-struct target_ops remote_ops = {
- "remote-ser", /* to_shortname */
- "Remote serial target in gdb-specific protocol with serial-packaging routines", /* to_longname */
- "Use a remote computer via a serial line, using a gdb-specific protocol.\n\
-Specify the serial device it is connected to (e.g. /dev/ttya).", /* to_doc */
- serial_open, /* to_open */
- serial_close, /* to_close */
- NULL, /* to_attach */
- remote_detach, /* to_detach */
- remote_resume, /* to_resume */
- remote_wait, /* to_wait */
- remote_fetch_registers, /* to_fetch_registers */
- remote_store_registers, /* to_store_registers */
- remote_prepare_to_store, /* to_prepare_to_store */
- NULL, /* to_convert_to_virtual */
- NULL, /* to_convert_from_virtual */
- remote_xfer_memory, /* to_xfer_memory */
- remote_files_info, /* to_files_info */
- NULL, /* to_insert_breakpoint */
- NULL, /* to_remove_breakpoint */
- NULL, /* to_terminal_init */
- NULL, /* to_terminal_inferior */
- NULL, /* to_terminal_ours_for_output */
- NULL, /* to_terminal_ours */
- NULL, /* to_terminal_info */
- NULL, /* to_kill */
- NULL, /* to_load */
- NULL, /* to_lookup_symbol */
- NULL, /* to_create_inferior */
- NULL, /* to_mourn_inferior */
- process_stratum, /* to_stratum */
- NULL, /* to_next */
- 1, /* to_has_all_memory */
- 1, /* to_has_memory */
- 1, /* to_has_stack */
- 1, /* to_has_registers */
- 1, /* to_has_execution */
- NULL, /* sections */
- NULL, /* sections_end */
- OPS_MAGIC /* to_magic */
-};
-
-void
-_initialize_remote ()
-{
- add_target (&remote_ops);
-
- add_show_from_set (
- add_set_cmd ("remotedebug", no_class, var_boolean, (char *)&kiodebug,
- "Set debugging of remote serial I/O.\n\
-When enabled, each packet sent or received with the remote target\n\
-is displayed.", &setlist),
- &showlist);
-}
-
projects / deliverable / binutils-gdb.git / blobdiff