From 2e0fa11c9fe652eb9bd5734b3f62f22bc5c49f64 Mon Sep 17 00:00:00 2001 From: Rob Savoye Date: Thu, 18 Aug 1994 05:16:12 +0000 Subject: [PATCH] New file for remote protocol to embedded HPPA targets. --- gdb/remote-pa.c | 1479 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1479 insertions(+) create mode 100644 gdb/remote-pa.c diff --git a/gdb/remote-pa.c b/gdb/remote-pa.c new file mode 100644 index 00000000000..6628dff85e7 --- /dev/null +++ b/gdb/remote-pa.c @@ -0,0 +1,1479 @@ +/* Remote target communications for serial-line targets in custom GDB protocol + Copyright 1988, 1991, 1992, 1993, 1994 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. + + A debug packet whose contents are + is encapsulated for transmission in the form: + + $ # CSUM1 CSUM2 + + must be ASCII alphanumeric and cannot include characters + '$' or '#'. If starts with two characters followed by + ':', then the existing stubs interpret this as a sequence number. + + CSUM1 and CSUM2 are ascii hex representation of an 8-bit + checksum of , 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 + + is as follows: + 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 + + write reg Pn...=r... Write register n... with value r..., + which contains two hex digits for each + byte in the register (target byte + order). + reply OK for success + ENN for an error + (not supported by all stubs). + + read mem mAA..AA,LLLL AA..AA is address, LLLL is length. + reply XX..XX XX..XX is mem contents + Can be fewer bytes than requested + if able to read only part of the data. + 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 (this includes the case + where only part of the data was + written). + + 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... TAAn...:r...;n:r...;n...:r...; + AA = signal number + n... = register number + r... = register contents + or... WAA The process exited, and AA is + the exit status. This is only + applicable for certains sorts of + targets. + kill request k + + toggle debug d toggle debug flag (see 386 & 68k stubs) + reset r reset -- see sparc stub. + reserved On other requests, the stub should + ignore the request and send an empty + response ($#). This way + we can extend the protocol and GDB + can tell whether the stub it is + talking to uses the old or the new. + search tAA:PP,MM Search backwards starting at address + AA for a match with pattern PP and + mask MM. PP and MM are 4 bytes. + Not supported by all stubs. + + general query qXXXX Request info about XXXX. + general set QXXXX=yyyy Set value of XXXX to yyyy. + query sect offs qOffsets Get section offsets. Reply is + Text=xxx;Data=yyy;Bss=zzz + console output Otext Send text to stdout. Only comes from + remote target. + + Responses can be run-length encoded to save space. A '*' means that + the next character is an ASCII encoding giving a repeat count which + stands for that many repititions of the character preceding the '*'. + The encoding is n+29, yielding a printable character where n >=3 + (which is where rle starts to win). Don't use an n > 126. + + So + "0* " means the same as "0000". */ + +#include "defs.h" +#include +#include +#include "frame.h" +#include "inferior.h" +#include "bfd.h" +#include "symfile.h" +#include "target.h" +#include "wait.h" +#include "terminal.h" +#include "gdbcmd.h" +#include "objfiles.h" +#include "gdb-stabs.h" + +#include "dcache.h" + +#ifdef USG +#include +#endif + +#include +#include "serial.h" + +/* Prototypes for local functions */ + +static int +remote_write_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len)); + +static int +remote_read_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len)); + +static void +remote_files_info PARAMS ((struct target_ops *ignore)); + +static int +remote_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr, int len, + int should_write, struct target_ops *target)); + +static void +remote_prepare_to_store PARAMS ((void)); + +static void +remote_fetch_registers PARAMS ((int regno)); + +static void +remote_resume PARAMS ((int pid, int step, enum target_signal siggnal)); + +static int +remote_start_remote PARAMS ((char *dummy)); + +static void +remote_open PARAMS ((char *name, int from_tty)); + +static void +remote_close PARAMS ((int quitting)); + +static void +remote_store_registers PARAMS ((int regno)); + +static void +getpkt PARAMS ((char *buf, int forever)); + +static void +putpkt PARAMS ((char *buf)); + +static void +remote_send PARAMS ((char *buf)); + +static int +readchar PARAMS ((int timeout)); + +static int remote_wait PARAMS ((int pid, struct target_waitstatus *status)); + +static int +tohex PARAMS ((int nib)); + +static int +fromhex PARAMS ((int a)); + +static void +remote_detach PARAMS ((char *args, int from_tty)); + +static void +remote_interrupt PARAMS ((int signo)); + +static void +remote_interrupt_twice PARAMS ((int signo)); + +static void +interrupt_query PARAMS ((void)); + +extern struct target_ops remote_ops; /* Forward decl */ + +/* This was 5 seconds, which is a long time to sit and wait. + Unless this is going though some terminal server or multiplexer or + other form of hairy serial connection, I would think 2 seconds would + be plenty. */ +static int remote_timeout = 2; + +#if 0 +int icache; +#endif + +/* Descriptor for I/O to remote machine. Initialize it to NULL so that + remote_open knows that we don't have a file open when the program + starts. */ +serial_t remote_desc = NULL; + +/* Having this larger than 400 causes us to be incompatible with m68k-stub.c + and i386-stub.c. Normally, no one would notice because it only matters + for writing large chunks of memory (e.g. in downloads). Also, this needs + to be more than 400 if required to hold the registers (see below, where + we round it up based on REGISTER_BYTES). */ +#define PBUFSIZ 400 + +/* 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. */ +/* The blank line after the #if seems to be required to work around a + bug in HP's PA compiler. */ +#if REGISTER_BYTES > MAXBUFBYTES + +#undef PBUFSIZ +#define PBUFSIZ (REGISTER_BYTES * 2 + 32) +#endif + +/* Should we try the 'P' request? If this is set to one when the stub + doesn't support 'P', the only consequence is some unnecessary traffic. */ +static int stub_supports_P = 1; + + +/* Clean up connection to a remote debugger. */ + +/* ARGSUSED */ +static void +remote_close (quitting) + int quitting; +{ + if (remote_desc) + SERIAL_CLOSE (remote_desc); + remote_desc = NULL; +} + +/* Query the remote side for the text, data and bss offsets. */ + +static void +get_offsets () +{ + unsigned char buf[PBUFSIZ]; + int nvals; + CORE_ADDR text_addr, data_addr, bss_addr; + struct section_offsets *offs; + + putpkt ("qOffsets"); + + getpkt (buf, 0); + + if (buf[0] == '\000') + return; /* Return silently. Stub doesn't support this + command. */ + if (buf[0] == 'E') + { + warning ("Remote failure reply: %s", buf); + return; + } + + nvals = sscanf (buf, "Text=%lx;Data=%lx;Bss=%lx", &text_addr, &data_addr, + &bss_addr); + if (nvals != 3) + error ("Malformed response to offset query, %s", buf); + + if (symfile_objfile == NULL) + return; + + offs = (struct section_offsets *) alloca (sizeof (struct section_offsets) + + symfile_objfile->num_sections + * sizeof (offs->offsets)); + memcpy (offs, symfile_objfile->section_offsets, + sizeof (struct section_offsets) + + symfile_objfile->num_sections + * sizeof (offs->offsets)); + + /* FIXME: This code assumes gdb-stabs.h is being used; it's broken + for xcoff, dwarf, sdb-coff, etc. But there is no simple + canonical representation for this stuff. (Just what does "text" + as seen by the stub mean, anyway? I think it means all sections + with SEC_CODE set, but we currently have no way to deal with that). */ + + ANOFFSET (offs, SECT_OFF_TEXT) = text_addr; + + /* This is a temporary kludge to force data and bss to use the same offsets + because that's what nlmconv does now. The real solution requires changes + to the stub and remote.c that I don't have time to do right now. */ + + ANOFFSET (offs, SECT_OFF_DATA) = data_addr; + ANOFFSET (offs, SECT_OFF_BSS) = data_addr; + + objfile_relocate (symfile_objfile, offs); +} + +/* Stub for catch_errors. */ + +static int +remote_start_remote (dummy) + char *dummy; +{ + immediate_quit = 1; /* Allow user to interrupt it */ + + /* Ack any packet which the remote side has already sent. */ + + SERIAL_WRITE (remote_desc, "+", 1); + + get_offsets (); /* Get text, data & bss offsets */ + + putpkt ("?"); /* initiate a query from remote machine */ + immediate_quit = 0; + + start_remote (); /* Initialize gdb process mechanisms */ + + return 1; +} + +/* Open a connection to a remote debugger. + NAME is the filename used for communication. */ + +static DCACHE *remote_dcache; + +static void +remote_open (name, from_tty) + char *name; + int from_tty; +{ + if (name == 0) + error ( +"To open a remote debug connection, you need to specify what serial\n\ +device is attached to the remote system (e.g. /dev/ttya)."); + + target_preopen (from_tty); + + unpush_target (&remote_ops); + + remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes); + + remote_desc = SERIAL_OPEN (name); + if (!remote_desc) + perror_with_name (name); + + if (baud_rate != -1) + { + if (SERIAL_SETBAUDRATE (remote_desc, baud_rate)) + { + SERIAL_CLOSE (remote_desc); + perror_with_name (name); + } + } + + SERIAL_RAW (remote_desc); + + /* If there is something sitting in the buffer we might take it as a + response to a command, which would be bad. */ + SERIAL_FLUSH_INPUT (remote_desc); + + if (from_tty) + { + puts_filtered ("Remote debugging using "); + puts_filtered (name); + puts_filtered ("\n"); + } + push_target (&remote_ops); /* Switch to using remote target now */ + + /* Start out by trying the 'P' request to set registers. We set this each + time that we open a new target so that if the user switches from one + stub to another, we can (if the target is closed and reopened) cope. */ + stub_supports_P = 1; + + /* Without this, some commands which require an active target (such as kill) + won't work. This variable serves (at least) double duty as both the pid + of the target process (if it has such), and as a flag indicating that a + target is active. These functions should be split out into seperate + variables, especially since GDB will someday have a notion of debugging + several processes. */ + + inferior_pid = 42000; + + /* Start the remote connection; if error (0), discard this target. + In particular, if the user quits, be sure to discard it + (we'd be in an inconsistent state otherwise). */ + if (!catch_errors (remote_start_remote, (char *)0, + "Couldn't establish connection to remote target\n", RETURN_MASK_ALL)) + pop_target(); +} + +/* 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) + puts_filtered ("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"); +} + +/* Convert number NIB to a hex digit. */ + +static int +tohex (nib) + int nib; +{ + if (nib < 10) + return '0'+nib; + else + return 'a'+nib-10; +} + +/* Tell the remote machine to resume. */ + +static void +remote_resume (pid, step, siggnal) + int pid, step; + enum target_signal siggnal; +{ + char buf[PBUFSIZ]; + + if (siggnal) + { + target_terminal_ours_for_output (); + printf_filtered + ("Can't send signals to a remote system. %s not sent.\n", + target_signal_to_name (siggnal)); + target_terminal_inferior (); + } + + dcache_flush (remote_dcache); + + strcpy (buf, step ? "s": "c"); + + putpkt (buf); +} + +/* Send ^C to target to halt it. Target will respond, and send us a + packet. */ + +static void +remote_interrupt (signo) + int signo; +{ + /* If this doesn't work, try more severe steps. */ + signal (signo, remote_interrupt_twice); + + if (remote_debug) + printf_unfiltered ("remote_interrupt called\n"); + + SERIAL_WRITE (remote_desc, "\003", 1); /* Send a ^C */ +} + +static void (*ofunc)(); + +/* The user typed ^C twice. */ +static void +remote_interrupt_twice (signo) + int signo; +{ + signal (signo, ofunc); + + interrupt_query (); + + signal (signo, remote_interrupt); +} + +/* Ask the user what to do when an interrupt is received. */ + +static void +interrupt_query () +{ + target_terminal_ours (); + + if (query ("Interrupted while waiting for the program.\n\ +Give up (and stop debugging it)? ")) + { + target_mourn_inferior (); + return_to_top_level (RETURN_QUIT); + } + + target_terminal_inferior (); +} + +/* 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 (pid, status) + int pid; + struct target_waitstatus *status; +{ + unsigned char buf[PBUFSIZ]; + + status->kind = TARGET_WAITKIND_EXITED; + status->value.integer = 0; + + while (1) + { + unsigned char *p; + + ofunc = (void (*)()) signal (SIGINT, remote_interrupt); + getpkt ((char *) buf, 1); + signal (SIGINT, ofunc); + + switch (buf[0]) + { + case 'E': /* Error of some sort */ + warning ("Remote failure reply: %s", buf); + continue; + case 'T': /* Status with PC, SP, FP, ... */ + { + int i; + long regno; + char regs[MAX_REGISTER_RAW_SIZE]; + + /* Expedited reply, containing Signal, {regno, reg} repeat */ + /* format is: 'Tssn...:r...;n...:r...;n...:r...;#cc', where + ss = signal number + n... = register number + r... = register contents + */ + + p = &buf[3]; /* after Txx */ + + while (*p) + { + unsigned char *p1; + + regno = strtol (p, &p1, 16); /* Read the register number */ + + if (p1 == p) + warning ("Remote sent badly formed register number: %s\nPacket: '%s'\n", + p1, buf); + + p = p1; + + if (*p++ != ':') + warning ("Malformed packet (missing colon): %s\nPacket: '%s'\n", + p, buf); + + if (regno >= NUM_REGS) + warning ("Remote sent bad register number %d: %s\nPacket: '%s'\n", + regno, p, buf); + + for (i = 0; i < REGISTER_RAW_SIZE (regno); i++) + { + if (p[0] == 0 || p[1] == 0) + warning ("Remote reply is too short: %s", buf); + regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]); + p += 2; + } + + if (*p++ != ';') + warning ("Remote register badly formatted: %s", buf); + + supply_register (regno, regs); + } + } + /* fall through */ + case 'S': /* Old style status, just signal only */ + status->kind = TARGET_WAITKIND_STOPPED; + status->value.sig = (enum target_signal) + (((fromhex (buf[1])) << 4) + (fromhex (buf[2]))); + + return inferior_pid; + case 'W': /* Target exited */ + { + /* The remote process exited. */ + status->kind = TARGET_WAITKIND_EXITED; + status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]); + return inferior_pid; + } + case 'O': /* Console output */ + fputs_filtered (buf + 1, gdb_stdout); + continue; + default: + warning ("Invalid remote reply: %s", buf); + continue; + } + } + return inferior_pid; +} + +/* Number of bytes of registers this stub implements. */ +static int register_bytes_found; + +/* 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); + + /* Unimplemented registers read as all bits zero. */ + memset (regs, 0, REGISTER_BYTES); + + /* We can get out of synch in various cases. If the first character + in the buffer is not a hex character, assume that has happened + and try to fetch another packet to read. */ + while ((buf[0] < '0' || buf[0] > '9') + && (buf[0] < 'a' || buf[0] > 'f')) + { + if (remote_debug) + printf_unfiltered ("Bad register packet; fetching a new packet\n"); + getpkt (buf, 0); + } + + /* 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) + break; + if (p[1] == 0) + { + warning ("Remote reply is of odd length: %s", buf); + /* Don't change register_bytes_found in this case, and don't + print a second warning. */ + goto supply_them; + } + regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]); + p += 2; + } + + if (i != register_bytes_found) + { + register_bytes_found = i; +#ifdef REGISTER_BYTES_OK + if (!REGISTER_BYTES_OK (i)) + warning ("Remote reply is too short: %s", buf); +#endif + } + + supply_them: + for (i = 0; i < NUM_REGS; i++) + supply_register (i, ®s[REGISTER_BYTE(i)]); +} + +/* Prepare to store registers. Since we may send them all (using a + 'G' request), we have to read out the ones we don't want to change + first. */ + +static void +remote_prepare_to_store () +{ + /* Make sure the entire registers array is valid. */ + read_register_bytes (0, (char *)NULL, REGISTER_BYTES); +} + +/* Store register REGNO, or all registers if REGNO == -1, from the contents + of REGISTERS. FIXME: ignores errors. */ + +static void +remote_store_registers (regno) + int regno; +{ + char buf[PBUFSIZ]; + int i; + char *p; + + if (regno >= 0 && stub_supports_P) + { + /* Try storing a single register. */ + char *regp; + + sprintf (buf, "P%x=", regno); + p = buf + strlen (buf); + regp = ®isters[REGISTER_BYTE (regno)]; + for (i = 0; i < REGISTER_RAW_SIZE (regno); ++i) + { + *p++ = tohex ((regp[i] >> 4) & 0xf); + *p++ = tohex (regp[i] & 0xf); + } + *p = '\0'; + remote_send (buf); + if (buf[0] != '\0') + { + /* The stub understands the 'P' request. We are done. */ + return; + } + + /* The stub does not support the 'P' request. Use 'G' instead, + and don't try using 'P' in the future (it will just waste our + time). */ + stub_supports_P = 0; + } + + buf[0] = 'G'; + + /* Command describes registers byte by byte, + each byte encoded as two hex characters. */ + + p = buf + 1; + /* remote_prepare_to_store insures that register_bytes_found gets set. */ + for (i = 0; i < register_bytes_found; i++) + { + *p++ = tohex ((registers[i] >> 4) & 0xf); + *p++ = tohex (registers[i] & 0xf); + } + *p = '\0'; + + remote_send (buf); +} + +#if 0 + +/* Use of the data cache is disabled because it loses for looking at + and changing hardware I/O ports and the like. Accepting `volatile' + would perhaps be one way to fix it, but a better way which would + win for more cases would be to use the executable file for the text + segment, like the `icache' code below but done cleanly (in some + target-independent place, perhaps in target_xfer_memory, perhaps + based on assigning each target a speed or perhaps by some simpler + mechanism). */ + +/* Read a word from remote address ADDR and return it. + This goes through the data cache. */ + +static int +remote_fetch_word (addr) + CORE_ADDR addr; +{ +#if 0 + if (icache) + { + extern CORE_ADDR text_start, text_end; + + if (addr >= text_start && addr < text_end) + { + int buffer; + xfer_core_file (addr, &buffer, sizeof (int)); + return buffer; + } + } +#endif + return dcache_fetch (remote_dcache, addr); +} + +/* Write a word WORD into remote address ADDR. + This goes through the data cache. */ + +static void +remote_store_word (addr, word) + CORE_ADDR addr; + int word; +{ + dcache_poke (remote_dcache, addr, word); +} +#endif /* 0 */ + +/* 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. + + Returns number of bytes transferred, or 0 for error. */ + +static int +remote_write_bytes (memaddr, myaddr, len) + CORE_ADDR memaddr; + unsigned char *myaddr; + int len; +{ + char buf[PBUFSIZ]; + int i; + char *p; + + /* FIXME-32x64: Need a version of print_address_numeric which puts the + result in a buffer like sprintf. */ + sprintf (buf, "M%lx,%x:", (unsigned long) 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'; + + putpkt (buf); + getpkt (buf, 0); + + if (buf[0] == 'E') + { + /* There is no correspondance between what the remote protocol uses + for errors and errno codes. We would like a cleaner way of + representing errors (big enough to include errno codes, bfd_error + codes, and others). But for now just return EIO. */ + errno = EIO; + return 0; + } + return len; +} + +/* 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. + + Returns number of bytes transferred, or 0 for error. */ + +static int +remote_read_bytes (memaddr, myaddr, len) + CORE_ADDR memaddr; + unsigned char *myaddr; + int len; +{ + char buf[PBUFSIZ]; + int i; + char *p; + + if (len > PBUFSIZ / 2 - 1) + abort (); + + /* FIXME-32x64: Need a version of print_address_numeric which puts the + result in a buffer like sprintf. */ + sprintf (buf, "m%lx,%x", (unsigned long) memaddr, len); + putpkt (buf); + getpkt (buf, 0); + + if (buf[0] == 'E') + { + /* There is no correspondance between what the remote protocol uses + for errors and errno codes. We would like a cleaner way of + representing errors (big enough to include errno codes, bfd_error + codes, and others). But for now just return EIO. */ + errno = EIO; + return 0; + } + + /* 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) + /* Reply is short. This means that we were able to read only part + of what we wanted to. */ + break; + myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]); + p += 2; + } + return i; +} + +/* 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 xfersize; + int bytes_xferred; + int total_xferred = 0; + + while (len > 0) + { + if (len > MAXBUFBYTES) + xfersize = MAXBUFBYTES; + else + xfersize = len; + + if (should_write) + bytes_xferred = remote_write_bytes (memaddr, + (unsigned char *)myaddr, xfersize); + else + bytes_xferred = remote_read_bytes (memaddr, + (unsigned char *)myaddr, xfersize); + + /* If we get an error, we are done xferring. */ + if (bytes_xferred == 0) + break; + + memaddr += bytes_xferred; + myaddr += bytes_xferred; + len -= bytes_xferred; + total_xferred += bytes_xferred; + } + return total_xferred; +} + +#if 0 +/* Enable after 4.12. */ + +void +remote_search (len, data, mask, startaddr, increment, lorange, hirange + addr_found, data_found) + int len; + char *data; + char *mask; + CORE_ADDR startaddr; + int increment; + CORE_ADDR lorange; + CORE_ADDR hirange; + CORE_ADDR *addr_found; + char *data_found; +{ + if (increment == -4 && len == 4) + { + long mask_long, data_long; + long data_found_long; + CORE_ADDR addr_we_found; + char buf[PBUFSIZ]; + long returned_long[2]; + char *p; + + mask_long = extract_unsigned_integer (mask, len); + data_long = extract_unsigned_integer (data, len); + sprintf (buf, "t%x:%x,%x", startaddr, data_long, mask_long); + putpkt (buf); + getpkt (buf, 0); + if (buf[0] == '\0') + { + /* The stub doesn't support the 't' request. We might want to + remember this fact, but on the other hand the stub could be + switched on us. Maybe we should remember it only until + the next "target remote". */ + generic_search (len, data, mask, startaddr, increment, lorange, + hirange, addr_found, data_found); + return; + } + + if (buf[0] == 'E') + /* There is no correspondance between what the remote protocol uses + for errors and errno codes. We would like a cleaner way of + representing errors (big enough to include errno codes, bfd_error + codes, and others). But for now just use EIO. */ + memory_error (EIO, startaddr); + p = buf; + addr_we_found = 0; + while (*p != '\0' && *p != ',') + addr_we_found = (addr_we_found << 4) + fromhex (*p++); + if (*p == '\0') + error ("Protocol error: short return for search"); + + data_found_long = 0; + while (*p != '\0' && *p != ',') + data_found_long = (data_found_long << 4) + fromhex (*p++); + /* Ignore anything after this comma, for future extensions. */ + + if (addr_we_found < lorange || addr_we_found >= hirange) + { + *addr_found = 0; + return; + } + + *addr_found = addr_we_found; + *data_found = store_unsigned_integer (data_we_found, len); + return; + } + generic_search (len, data, mask, startaddr, increment, lorange, + hirange, addr_found, data_found); +} +#endif /* 0 */ + +static void +remote_files_info (ignore) + struct target_ops *ignore; +{ + puts_filtered ("Debugging a target over a serial line.\n"); +} + +/* Stuff for dealing with the packets which are part of this protocol. + See comment at top of file for details. */ + +/* Read a single character from the remote end, masking it down to 7 bits. */ + +static int +readchar (timeout) + int timeout; +{ + int ch; + + ch = SERIAL_READCHAR (remote_desc, timeout); + + switch (ch) + { + case SERIAL_EOF: + error ("Remote connection closed"); + case SERIAL_ERROR: + perror_with_name ("Remote communication error"); + case SERIAL_TIMEOUT: + return ch; + default: + return ch & 0x7f; + } +} + +/* 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, 0); + + if (buf[0] == 'E') + error ("Remote failure reply: %s", buf); +} + +/* 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); + int 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++ = '$'; + + for (i = 0; i < cnt; i++) + { + csum += buf[i]; + *p++ = buf[i]; + } + *p++ = '#'; + *p++ = tohex ((csum >> 4) & 0xf); + *p++ = tohex (csum & 0xf); + + /* Send it over and over until we get a positive ack. */ + + while (1) + { + int started_error_output = 0; + + if (remote_debug) + { + *p = '\0'; + printf_unfiltered ("Sending packet: %s...", buf2); + gdb_flush(gdb_stdout); + } + if (SERIAL_WRITE (remote_desc, buf2, p - buf2)) + perror_with_name ("putpkt: write failed"); + + /* read until either a timeout occurs (-2) or '+' is read */ + while (1) + { + ch = readchar (remote_timeout); + + if (remote_debug) + { + switch (ch) + { + case '+': + case SERIAL_TIMEOUT: + case '$': + if (started_error_output) + { + putc_unfiltered ('\n'); + started_error_output = 0; + } + } + } + + switch (ch) + { + case '+': + if (remote_debug) + printf_unfiltered("Ack\n"); + return; + case SERIAL_TIMEOUT: + break; /* Retransmit buffer */ + case '$': + { + unsigned char junkbuf[PBUFSIZ]; + + /* It's probably an old response, and we're out of sync. Just + gobble up the packet and ignore it. */ + getpkt (junkbuf, 0); + continue; /* Now, go look for + */ + } + default: + if (remote_debug) + { + if (!started_error_output) + { + started_error_output = 1; + printf_unfiltered ("putpkt: Junk: "); + } + putc_unfiltered (ch & 0177); + } + continue; + } + break; /* Here to retransmit */ + } + +#if 0 + /* This is wrong. If doing a long backtrace, the user should be + able to get out next time we call QUIT, without anything as violent + as interrupt_query. If we want to provide a way out of here + without getting to the next QUIT, it should be based on hitting + ^C twice as in remote_wait. */ + if (quit_flag) + { + quit_flag = 0; + interrupt_query (); + } +#endif + } +} + +/* Come here after finding the start of the frame. Collect the rest into BUF, + verifying the checksum, length, and handling run-length compression. + Returns 0 on any error, 1 on success. */ + +static int +read_frame (buf) + char *buf; +{ + unsigned char csum; + char *bp; + int c; + + csum = 0; + bp = buf; + + while (1) + { + c = readchar (remote_timeout); + + switch (c) + { + case SERIAL_TIMEOUT: + if (remote_debug) + puts_filtered ("Timeout in mid-packet, retrying\n"); + return 0; + case '$': + if (remote_debug) + puts_filtered ("Saw new packet start in middle of old one\n"); + return 0; /* Start a new packet, count retries */ + case '#': + { + unsigned char pktcsum; + + *bp = '\000'; + + pktcsum = fromhex (readchar (remote_timeout)) << 4; + pktcsum |= fromhex (readchar (remote_timeout)); + + if (csum == pktcsum) + return 1; + + printf_filtered ("Bad checksum, sentsum=0x%x, csum=0x%x, buf=", + pktcsum, csum); + puts_filtered (buf); + puts_filtered ("\n"); + + return 0; + } + case '*': /* Run length encoding */ + csum += c; + c = readchar (remote_timeout); + csum += c; + c = c - ' ' + 3; /* Compute repeat count */ + + if (bp + c - 1 < buf + PBUFSIZ - 1) + { + memset (bp, *(bp - 1), c); + bp += c; + continue; + } + + *bp = '\0'; + printf_filtered ("Repeat count %d too large for buffer: ", c); + puts_filtered (buf); + puts_filtered ("\n"); + return 0; + + default: + if (bp < buf + PBUFSIZ - 1) + { + *bp++ = c; + csum += c; + continue; + } + + *bp = '\0'; + puts_filtered ("Remote packet too long: "); + puts_filtered (buf); + puts_filtered ("\n"); + + return 0; + } + } +} + +/* Read a packet from the remote machine, with error checking, + and store it in BUF. BUF is expected to be of size PBUFSIZ. + If FOREVER, wait forever rather than timing out; this is used + while the target is executing user code. */ + +static void +getpkt (buf, forever) + char *buf; + int forever; +{ + char *bp; + int c; + int tries; + int timeout; + int val; + + if (forever) + timeout = -1; + else + timeout = remote_timeout; + +#define MAX_TRIES 10 + + for (tries = 1; tries <= MAX_TRIES; tries++) + { + /* This can loop forever if the remote side sends us characters + continuously, but if it pauses, we'll get a zero from readchar + because of timeout. Then we'll count that as a retry. */ + + /* Note that we will only wait forever prior to the start of a packet. + After that, we expect characters to arrive at a brisk pace. They + should show up within remote_timeout intervals. */ + + do + { + c = readchar (timeout); + + if (c == SERIAL_TIMEOUT) + { + if (remote_debug) + puts_filtered ("Timed out.\n"); + goto retry; + } + } + while (c != '$'); + + /* We've found the start of a packet, now collect the data. */ + + val = read_frame (buf); + + if (val == 1) + { + if (remote_debug) + fprintf_unfiltered (gdb_stderr, "Packet received: %s\n", buf); + SERIAL_WRITE (remote_desc, "+", 1); + return; + } + + /* Try the whole thing again. */ +retry: + SERIAL_WRITE (remote_desc, "-", 1); + } + + /* We have tried hard enough, and just can't receive the packet. Give up. */ + + printf_unfiltered ("Ignoring packet error, continuing...\n"); + SERIAL_WRITE (remote_desc, "+", 1); +} + +static void +remote_kill () +{ + putpkt ("k"); + /* Don't wait for it to die. I'm not really sure it matters whether + we do or not. For the existing stubs, kill is a noop. */ + target_mourn_inferior (); +} + +static void +remote_mourn () +{ + unpush_target (&remote_ops); + generic_mourn_inferior (); +} + +#ifdef REMOTE_BREAKPOINT + +/* On some machines, e.g. 68k, we may use a different breakpoint instruction + than other targets. */ +static unsigned char break_insn[] = REMOTE_BREAKPOINT; + +/* Check that it fits in BREAKPOINT_MAX bytes. */ +static unsigned char check_break_insn_size[BREAKPOINT_MAX] = REMOTE_BREAKPOINT; + +#else /* No REMOTE_BREAKPOINT. */ + +/* Same old breakpoint instruction. This code does nothing different + than mem-break.c. */ +static unsigned char break_insn[] = BREAKPOINT; + +#endif /* No REMOTE_BREAKPOINT. */ + +/* Insert a breakpoint on targets that don't have any better breakpoint + support. We read the contents of the target location and stash it, + then overwrite it with a breakpoint instruction. ADDR is the target + location in the target machine. CONTENTS_CACHE is a pointer to + memory allocated for saving the target contents. It is guaranteed + by the caller to be long enough to save sizeof BREAKPOINT bytes (this + is accomplished via BREAKPOINT_MAX). */ + +static int +remote_insert_breakpoint (addr, contents_cache) + CORE_ADDR addr; + char *contents_cache; +{ + int val; + + val = target_read_memory (addr, contents_cache, sizeof break_insn); + + if (val == 0) + val = target_write_memory (addr, (char *)break_insn, sizeof break_insn); + + return val; +} + +static int +remote_remove_breakpoint (addr, contents_cache) + CORE_ADDR addr; + char *contents_cache; +{ + return target_write_memory (addr, contents_cache, sizeof break_insn); +} + +/* Define the target subroutine names */ + +struct target_ops remote_ops = { + "remote", /* to_shortname */ + "Remote serial target in gdb-specific protocol", /* 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). or telnet port", /* to_doc */ + remote_open, /* to_open */ + remote_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 */ + remote_xfer_memory, /* to_xfer_memory */ + remote_files_info, /* to_files_info */ + + remote_insert_breakpoint, /* to_insert_breakpoint */ + remote_remove_breakpoint, /* 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 */ + remote_kill, /* to_kill */ + generic_load, /* to_load */ + NULL, /* to_lookup_symbol */ + NULL, /* to_create_inferior */ + remote_mourn, /* to_mourn_inferior */ + 0, /* to_can_run */ + 0, /* to_notice_signals */ + 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); +} -- 2.30.2