This patch adds support for GDB packets and serial console demuxing. To use
it start flterm with --gdb-passthrough. Then start gdb and run the
following commands:
set remote interrupt-on-connect on
target remote <pseudo terminal printed by flterm>
Note: there is _no_ 'set remote interrupt-sequence BREAK'. flterm takes
care of converting Ctrl+C (ETX) to a BREAK.
---
tools/flterm.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 192 insertions(+), 25 deletions(-)
diff --git a/tools/flterm.c b/tools/flterm.c
index 5271a73..6940902 100644
--- a/tools/flterm.c
+++ b/tools/flterm.c
@@ -1,6 +1,8 @@
/*
* Milkymist VJ SoC
- * Copyright (C) 2007, 2008, 2009 Sebastien Bourdeauducq
+ * Copyright (C) 2007, 2008, 2009, 2010, 2011 Sebastien Bourdeauducq
+ * Copyright (C) 2011 Michael Walle
+ * Copyright (C) 2004 MontaVista Software, Inc
*
* 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
@@ -36,6 +38,8 @@
#define DEFAULT_CMDLINEADR (0x41000000)
#define DEFAULT_INITRDADR (0x41002000)
+#define GDBBUFLEN 1000
+
unsigned int crc16_table[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
@@ -71,6 +75,8 @@ unsigned int crc16_table[256] = {
0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
};
+static int debug = 0;
+
static unsigned short crc16(const void *_buffer, int len)
{
const unsigned char *buffer = (const unsigned char *)_buffer;
@@ -283,18 +289,104 @@ static void answer_magic(int serialfd,
close(kernelfd);
}
+static int hex(unsigned char c)
+{
+ if(c >= 'a' && c <= 'f') {
+ return c - 'a' + 10;
+ }
+ if(c >= '0' && c <= '9') {
+ return c - '0';
+ }
+ if(c >= 'A' && c <= 'F') {
+ return c - 'A' + 10;
+ }
+ return 0;
+}
+
+/*
+ * This is taken from kdmx2.
+ * Author: Tom Rini <[email protected]>
+ */
+static void gdb_process_packet(int infd, int outfd, int altfd)
+{
+ /* gdb packet handling */
+ char gdbbuf[GDBBUFLEN + 1];
+ int pos = 0;
+ unsigned char runcksum = 0;
+ unsigned char recvcksum = 0;
+ struct pollfd fds;
+ char c;
+ int seen_hash = 0;
+
+ fds.fd = infd;
+ fds.events = POLLIN;
+
+ memset(gdbbuf, 0, sizeof(gdbbuf));
+ gdbbuf[0] = '$';
+ pos++;
+
+ while (1) {
+ fds.revents = 0;
+ if(poll(&fds, 1, 100) == 0) {
+ /* timeout */
+ if (altfd != -1) {
+ write(altfd, gdbbuf, pos);
+ }
+ break;
+ }
+ if (pos == GDBBUFLEN) {
+ if (altfd != -1) {
+ write(altfd, gdbbuf, pos);
+ }
+ break;
+ }
+ read(infd, &c, 1);
+ gdbbuf[pos++] = c;
+ if(c == '#') {
+ seen_hash = 1;
+ } else if (seen_hash == 0) {
+ runcksum += c;
+ } else if (seen_hash == 1) {
+ recvcksum = hex(c) << 4;
+ seen_hash = 2;
+ } else if (seen_hash == 2) {
+ recvcksum |= hex(c);
+ seen_hash = 3;
+ }
+
+ if (seen_hash == 3) {
+ /* we're done */
+ runcksum %= 256;
+ if (recvcksum == runcksum) {
+ if (debug) {
+ fprintf(stderr, "[GDB %s]\n", gdbbuf);
+ }
+ write(outfd, gdbbuf, pos);
+ } else {
+ if (altfd != -1) {
+ write(altfd, gdbbuf, pos);
+ }
+ }
+ seen_hash = 0;
+ break;
+ }
+ }
+}
+
static void do_terminal(char *serial_port,
- int doublerate,
+ int doublerate, int gdb_passthrough,
const char *kernel_image, unsigned int kernel_address,
const char *cmdline, unsigned int cmdline_address,
const char *initrd_image, unsigned int initrd_address)
{
int serialfd;
+ int gdbfd = -1;
struct termios my_termios;
char c;
int recognized;
- struct pollfd fds[2];
+ struct pollfd fds[3];
int flags;
+ int rsp_pending = 0;
/* Open and configure the serial port */
serialfd = open(serial_port, O_RDWR|O_NOCTTY);
@@ -302,7 +394,7 @@ static void do_terminal(char *serial_port,
perror("Unable to open serial port");
return;
}
-
+
/* Thanks to Julien Schmitt (GTKTerm) for figuring out the correct
parameters
* to put into that weird struct.
*/
@@ -319,7 +411,7 @@ static void do_terminal(char *serial_port,
tcsetattr(serialfd, TCSANOW, &my_termios);
tcflush(serialfd, TCOFLUSH);
tcflush(serialfd, TCIFLUSH);
-
+
/* Prepare the fdset for poll() */
fds[0].fd = 0;
fds[0].events = POLLIN;
@@ -329,47 +421,103 @@ static void do_terminal(char *serial_port,
recognized = 0;
flags = fcntl(serialfd, F_GETFL, 0);
while(1) {
+ if (gdbfd == -1 && gdb_passthrough) {
+ gdbfd = open("/dev/ptmx", O_RDWR);
+ if(grantpt(gdbfd) != 0) {
+ perror("grantpt()");
+ return;
+ }
+ if(unlockpt(gdbfd) != 0) {
+ perror("unlockpt()");
+ return;
+ }
+ printf("[GDB passthrough] use %s as GDB remote
device\n",
+ ptsname(gdbfd));
+ fds[2].fd = gdbfd;
+ fds[2].events = POLLIN;
+ }
+
fds[0].revents = 0;
fds[1].revents = 0;
-
+ fds[2].revents = 0;
+
/* poll() behaves strangely when the serial port descriptor is
in
* blocking mode. So work around this.
*/
fcntl(serialfd, F_SETFL, flags|O_NONBLOCK);
- if(poll(&fds[0], 2, -1) < 0) break;
+ if(poll(&fds[0], (gdbfd == -1) ? 2 : 3, -1) < 0) break;
fcntl(serialfd, F_SETFL, flags);
-
+
if(fds[0].revents & POLLIN) {
- read(0, &c, 1);
+ if (read(0, &c, 1) <= 0) break;
if(write(serialfd, &c, 1) <= 0) break;
}
-
+
+ if(fds[2].revents & POLLIN) {
+ rsp_pending = 1;
+ if (read(gdbfd, &c, 1) <= 0) break;
+ if (c == '\03') {
+ /* convert ETX to breaks */
+ if (debug) {
+ fprintf(stderr, "[GDB BREAK]\n");
+ }
+ tcsendbreak(serialfd, 0);
+ } else if (c == '$') {
+ gdb_process_packet(gdbfd, serialfd, -1);
+ } else if (c == '+' || c == '-') {
+ write(serialfd, &c, 1);
+ } else {
+ fprintf(stderr, "Internal error (line %d)",
__LINE__);
+ exit(1);
+ }
+ }
+
+ if(fds[2].revents & POLLHUP) {
+ /* close and reopen new pair */
+ close(gdbfd);
+ gdbfd = -1;
+ continue;
+ }
+
if(fds[1].revents & POLLIN) {
if(read(serialfd, &c, 1) <= 0) break;
- write(0, &c, 1);
+ if(gdbfd != -1 && rsp_pending && (c == '+' || c ==
'-')) {
+ rsp_pending = 0;
+ write(gdbfd, &c, 1);
+ } else if (gdbfd != -1 && c == '$') {
+ gdb_process_packet(serialfd, gdbfd, 0);
+ } else {
+ /* write to terminal */
+ write(0, &c, 1);
- if(c == sfl_magic_req[recognized]) {
- recognized++;
- if(recognized == SFL_MAGIC_LEN) {
- /* We've got the magic string ! */
- recognized = 0;
- answer_magic(serialfd,
- kernel_image, kernel_address,
- cmdline, cmdline_address,
- initrd_image, initrd_address);
+ if(c == sfl_magic_req[recognized]) {
+ recognized++;
+ if(recognized == SFL_MAGIC_LEN) {
+ /* We've got the magic string !
*/
+ recognized = 0;
+ answer_magic(serialfd,
+ kernel_image,
kernel_address,
+ cmdline,
cmdline_address,
+ initrd_image,
initrd_address);
+ }
+ } else {
+ if(c == sfl_magic_req[0]) recognized =
1; else recognized = 0;
}
- } else {
- if(c == sfl_magic_req[0]) recognized = 1; else
recognized = 0;
}
}
}
close(serialfd);
+ if(gdbfd != -1) {
+ close(gdbfd);
+ }
}
enum {
OPTION_PORT,
+ OPTION_GDB_PASSTHROUGH,
OPTION_DOUBLERATE,
+ OPTION_DEBUG,
OPTION_KERNEL,
OPTION_KERNELADR,
OPTION_CMDLINE,
@@ -385,6 +533,16 @@ static const struct option options[] = {
.val = OPTION_PORT
},
{
+ .name = "gdb-passthrough",
+ .has_arg = 0,
+ .val = OPTION_GDB_PASSTHROUGH
+ },
+ {
+ .name = "debug",
+ .has_arg = 0,
+ .val = OPTION_DEBUG
+ },
+ {
.name = "double-rate",
.has_arg = 0,
.val = OPTION_DOUBLERATE
@@ -433,7 +591,8 @@ static void print_usage()
fprintf(stderr, "it under the terms of the GNU General Public License
as published by\n");
fprintf(stderr, "the Free Software Foundation, version 3 of the
License.\n\n");
- fprintf(stderr, "Usage: flterm --port <port> [--double-rate]\n");
+ fprintf(stderr, "Usage: flterm --port <port>\n");
+ fprintf(stderr, " [--double-rate] [--gdb-passthrough]
[--debug]\n");
fprintf(stderr, " --kernel <kernel_image> [--kernel-adr
<address>]\n");
fprintf(stderr, " [--cmdline <cmdline> [--cmdline-adr
<address>]]\n");
fprintf(stderr, " [--initrd <initrd_image> [--initrd-adr
<address>]]\n\n");
@@ -448,6 +607,7 @@ int main(int argc, char *argv[])
int opt;
char *serial_port;
int doublerate;
+ int gdb_passthrough;
char *kernel_image;
unsigned int kernel_address;
char *cmdline;
@@ -460,6 +620,7 @@ int main(int argc, char *argv[])
/* Fetch command line arguments */
serial_port = NULL;
doublerate = 0;
+ gdb_passthrough = 0;
kernel_image = NULL;
kernel_address = DEFAULT_KERNELADR;
cmdline = NULL;
@@ -479,6 +640,12 @@ int main(int argc, char *argv[])
case OPTION_DOUBLERATE:
doublerate = 1;
break;
+ case OPTION_DEBUG:
+ debug = 1;
+ break;
+ case OPTION_GDB_PASSTHROUGH:
+ gdb_passthrough = 1;
+ break;
case OPTION_KERNEL:
free(kernel_image);
kernel_image = strdup(optarg);
@@ -519,9 +686,9 @@ int main(int argc, char *argv[])
ntty = otty;
ntty.c_lflag &= ~(ECHO | ICANON);
tcsetattr(0, TCSANOW, &ntty);
-
+
/* Do the bulk of the work */
- do_terminal(serial_port, doublerate,
+ do_terminal(serial_port, doublerate, gdb_passthrough,
kernel_image, kernel_address,
cmdline, cmdline_address,
initrd_image, initrd_address);
--
1.7.2.3
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