Add xspike program

8 files changed, 219 insertions, 62 deletions

diff --git a/riscv/interactive.cc b/riscv/interactive.cc
index fc993e5..6117d01 100644
--- a/riscv/interactive.cc
+++ b/riscv/interactive.cc
@@ -3,6 +3,7 @@
 #include "sim.h"
 #include "htif.h"
 #include <sys/mman.h>
+#include <termios.h>
 #include <map>
 #include <iostream>
 #include <climits>
@@ -14,65 +15,76 @@
 #include <string>
 #include <vector>
 
-static std::string readline()
+static std::string readline(int fd)
 {
+  struct termios tios;
+  bool noncanonical = tcgetattr(fd, &tios) == 0 && (tios.c_lflag & ICANON) == 0;
+
   std::string s;
-  while (1)
+  for (char ch; read(fd, &ch, 1) == 1; )
   {
-    char ch;
-    assert(read(1, &ch, 1) == 1);
-
     if (ch == '\x7f')
     {
       if (s.empty())
         continue;
       s.erase(s.end()-1);
+
+      if (noncanonical && write(fd, "\b \b", 3) != 3)
+        ; // shut up gcc
     }
+    else if (noncanonical && write(fd, &ch, 1) != 1)
+      ; // shut up gcc
 
-    assert(write(1, &ch, 1) == 1);
     if (ch == '\n')
-      return s;
+      break;
     if (ch != '\x7f')
       s += ch;
   }
+  return s;
 }
 
 void sim_t::interactive()
 {
-  std::cout << ": " << std::flush;
-  std::string s = readline();
-
-  std::stringstream ss(s);
-  std::string cmd, tmp;
-  std::vector<std::string> args;
-  if (!(ss >> cmd))
+  while (true)
   {
-    interactive_run_noisy(std::string("r"), std::vector<std::string>(1,"1"));
-    return;
-  }
-  while (ss >> tmp)
-    args.push_back(tmp);
-
-  typedef void (sim_t::*interactive_func)(const std::string&, const std::vector<std::string>&);
-  std::map<std::string,interactive_func> funcs;
-
-  funcs["r"] = &sim_t::interactive_run_noisy;
-  funcs["rs"] = &sim_t::interactive_run_silent;
-  funcs["reg"] = &sim_t::interactive_reg;
-  funcs["fregs"] = &sim_t::interactive_fregs;
-  funcs["fregd"] = &sim_t::interactive_fregd;
-  funcs["mem"] = &sim_t::interactive_mem;
-  funcs["str"] = &sim_t::interactive_str;
-  funcs["until"] = &sim_t::interactive_until;
-  funcs["while"] = &sim_t::interactive_until;
-  funcs["q"] = &sim_t::interactive_quit;
-
-  try
-  {
-    if(funcs.count(cmd))
-      (this->*funcs[cmd])(cmd, args);
+    std::cerr << ": " << std::flush;
+    std::string s = readline(2);
+
+    std::stringstream ss(s);
+    std::string cmd, tmp;
+    std::vector<std::string> args;
+
+    if (!(ss >> cmd))
+    {
+      step(1, true);
+      continue;
+    }
+
+    while (ss >> tmp)
+      args.push_back(tmp);
+
+    typedef void (sim_t::*interactive_func)(const std::string&, const std::vector<std::string>&);
+    std::map<std::string,interactive_func> funcs;
+
+    funcs["r"] = &sim_t::interactive_run_noisy;
+    funcs["rs"] = &sim_t::interactive_run_silent;
+    funcs["reg"] = &sim_t::interactive_reg;
+    funcs["fregs"] = &sim_t::interactive_fregs;
+    funcs["fregd"] = &sim_t::interactive_fregd;
+    funcs["mem"] = &sim_t::interactive_mem;
+    funcs["str"] = &sim_t::interactive_str;
+    funcs["until"] = &sim_t::interactive_until;
+    funcs["while"] = &sim_t::interactive_until;
+    funcs["q"] = &sim_t::interactive_quit;
+
+    try
+    {
+      if(funcs.count(cmd))
+        (this->*funcs[cmd])(cmd, args);
+    }
+    catch(trap_t t) {}
   }
-  catch(trap_t t) {}
+  ctrlc_pressed = false;
 }
 
 void sim_t::interactive_run_noisy(const std::string& cmd, const std::vector<std::string>& args)
@@ -88,12 +100,14 @@ void sim_t::interactive_run_silent(const std::string& cmd, const std::vector<std
 void sim_t::interactive_run(const std::string& cmd, const std::vector<std::string>& args, bool noisy)
 {
   size_t steps = args.size() ? atoll(args[0].c_str()) : -1;
-  step(steps, noisy);
+  ctrlc_pressed = false;
+  for (size_t i = 0; i < steps && !ctrlc_pressed; i++)
+    step(1, noisy);
 }
 
 void sim_t::interactive_quit(const std::string& cmd, const std::vector<std::string>& args)
 {
-  stop();
+  exit(0);
 }
 
 reg_t sim_t::get_pc(const std::vector<std::string>& args)
@@ -220,10 +234,11 @@ void sim_t::interactive_str(const std::string& cmd, const std::vector<std::strin
 
 void sim_t::interactive_until(const std::string& cmd, const std::vector<std::string>& args)
 {
+  bool cmd_until = cmd == "until";
+
   if(args.size() < 3)
     return;
 
-  std::string scmd = args[0];
   reg_t val = strtol(args[args.size()-1].c_str(),NULL,16);
   if(val == LONG_MAX)
     val = strtoul(args[args.size()-1].c_str(),NULL,16);
@@ -231,21 +246,23 @@ void sim_t::interactive_until(const std::string& cmd, const std::vector<std::str
   std::vector<std::string> args2;
   args2 = std::vector<std::string>(args.begin()+1,args.end()-1);
 
+  auto func = args[0] == "reg" ? &sim_t::get_reg :
+              args[0] == "pc"  ? &sim_t::get_pc :
+              args[0] == "mem" ? &sim_t::get_mem :
+              NULL;
+
+  if (func == NULL)
+    return;
+
+  ctrlc_pressed = false;
+
   while (1)
   {
-    reg_t current;
-    if(scmd == "reg")
-      current = get_reg(args2);
-    else if(scmd == "pc")
-      current = get_pc(args2);
-    else if(scmd == "mem")
-      current = get_mem(args2);
-    else
-      return;
-
-    if(cmd == "until" && current == val)
+    reg_t current = (this->*func)(args2);
+
+    if (cmd_until == (current == val))
       break;
-    if(cmd == "while" && current != val)
+    if (ctrlc_pressed)
       break;
 
     step(1, false);
diff --git a/riscv/processor.cc b/riscv/processor.cc
index 74a98a8..843279b 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -177,11 +177,11 @@ void processor_t::take_trap(reg_t t, bool noisy)
   if(noisy)
   {
     if ((sreg_t)t < 0)
-      printf("core %3d: interrupt %d, epc 0x%016" PRIx64 "\n",
-             id, uint8_t(t), pc);
+      fprintf(stderr, "core %3d: interrupt %d, epc 0x%016" PRIx64 "\n",
+              id, uint8_t(t), pc);
     else
-      printf("core %3d: trap %s, epc 0x%016" PRIx64 "\n",
-             id, trap_name(trap_t(t)), pc);
+      fprintf(stderr, "core %3d: trap %s, epc 0x%016" PRIx64 "\n",
+              id, trap_name(trap_t(t)), pc);
   }
 
   // switch to supervisor, set previous supervisor bit, disable traps
@@ -202,8 +202,8 @@ void processor_t::disasm(insn_t insn, reg_t pc)
 {
   // the disassembler is stateless, so we share it
   static disassembler disasm;
-  printf("core %3d: 0x%016" PRIx64 " (0x%08" PRIx32 ") %s\n",
-         id, pc, insn.bits, disasm.disassemble(insn).c_str());
+  fprintf(stderr, "core %3d: 0x%016" PRIx64 " (0x%08" PRIx32 ") %s\n",
+          id, pc, insn.bits, disasm.disassemble(insn).c_str());
 }
 
 void processor_t::set_pcr(int which, reg_t val)
diff --git a/riscv/riscv.mk.in b/riscv/riscv.mk.in
index c4448ff..ce131d4 100644
--- a/riscv/riscv.mk.in
+++ b/riscv/riscv.mk.in
@@ -4,6 +4,8 @@ riscv_subproject_deps = \
 
 riscv_install_prog_srcs = \
 	spike.cc \
+	xspike.cc \
+	termios-xspike.cc \
 
 riscv_hdrs = \
 	htif.h \
diff --git a/riscv/sim.cc b/riscv/sim.cc
index c6ca04a..6534900 100644
--- a/riscv/sim.cc
+++ b/riscv/sim.cc
@@ -7,11 +7,22 @@
 #include <climits>
 #include <cstdlib>
 #include <cassert>
+#include <signal.h>
+
+volatile bool ctrlc_pressed = false;
+static void handle_signal(int sig)
+{
+  if (ctrlc_pressed)
+    exit(-1);
+  ctrlc_pressed = true;
+  signal(sig, &handle_signal);
+}
 
 sim_t::sim_t(size_t _nprocs, size_t mem_mb, const std::vector<std::string>& args)
   : htif(new htif_isasim_t(this, args)),
     procs(_nprocs), current_step(0), current_proc(0), debug(false)
 {
+  signal(SIGINT, &handle_signal);
   // allocate target machine's memory, shrinking it as necessary
   // until the allocation succeeds
   size_t memsz0 = (size_t)mem_mb << 20;
@@ -67,7 +78,7 @@ void sim_t::run()
 {
   while (!htif->done())
   {
-    if (debug)
+    if (debug || ctrlc_pressed)
       interactive();
     else
       step(INTERLEAVE, false);
diff --git a/riscv/sim.h b/riscv/sim.h
index 2bc69f0..560bb70 100644
--- a/riscv/sim.h
+++ b/riscv/sim.h
@@ -70,4 +70,6 @@ private:
   friend class htif_isasim_t;
 };
 
+extern volatile bool ctrlc_pressed;
+
 #endif
diff --git a/riscv/spike.cc b/riscv/spike.cc
index 8fbe25b..00997bd 100644
--- a/riscv/spike.cc
+++ b/riscv/spike.cc
@@ -19,7 +19,6 @@ static void help()
   fprintf(stderr, "  -m <n>             Provide <n> MB of target memory\n");
   fprintf(stderr, "  -d                 Interactive debug mode\n");
   fprintf(stderr, "  -h                 Print this help message\n");
-  fprintf(stderr, "  -h                 Print this help message\n");
   fprintf(stderr, "  --ic=<S>:<W>:<B>   Instantiate a cache model with S sets,\n");
   fprintf(stderr, "  --dc=<S>:<W>:<B>     W ways, and B-byte blocks (with S and\n");
   fprintf(stderr, "  --l2=<S>:<W>:<B>     B both powers of 2).\n");
@@ -37,6 +36,7 @@ int main(int argc, char** argv)
 
   option_parser_t parser;
   parser.help(&help);
+  parser.option('h', 0, 0, [&](const char* s){help();});
   parser.option('d', 0, 0, [&](const char* s){debug = true;});
   parser.option('p', 0, 1, [&](const char* s){nprocs = atoi(s);});
   parser.option('m', 0, 1, [&](const char* s){mem_mb = atoi(s);});
diff --git a/riscv/termios-xspike.cc b/riscv/termios-xspike.cc
new file mode 100644
index 0000000..e533933
--- /dev/null
+++ b/riscv/termios-xspike.cc
@@ -0,0 +1,29 @@
+// See LICENSE for license details.
+
+// termios-xspike sets up a canonical terminal and blocks forever.
+// It allows us to send Ctrl-C etc. to the target machine.
+
+#include <unistd.h>
+#include <termios.h>
+#include <signal.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int main()
+{
+  struct termios old_tios;
+  if (tcgetattr(0, &old_tios) < 0)
+    return -1;
+
+  signal(SIGTERM, [](int) { });
+
+  struct termios new_tios = old_tios;
+  new_tios.c_lflag &= ~(ICANON | ECHO | ISIG);
+  if (tcsetattr(0, TCSANOW, &new_tios) < 0)
+    return -1;
+
+  pause();
+
+  return tcsetattr(0, TCSANOW, &old_tios);
+}
diff --git a/riscv/xspike.cc b/riscv/xspike.cc
new file mode 100644
index 0000000..fd7c5c8
--- /dev/null
+++ b/riscv/xspike.cc
@@ -0,0 +1,96 @@
+// See LICENSE for license details.
+
+// xspike forks an xterm for spike's target machine console,
+// preserving the current terminal for debugging.
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <cstdio>
+#include <climits>
+#include <cstring>
+#include <stdexcept>
+
+static pid_t fork_spike(int tty_fd, int argc, char** argv);
+static pid_t fork_xterm(int* tty_fd);
+
+int main(int argc, char** argv)
+{
+  int tty_fd, wait_status, ret = -1;
+  pid_t xterm, spike;
+
+  static bool signal_exit = false;
+  auto handle_signal = [](int) { signal_exit = true; };
+  signal(SIGINT, handle_signal);
+
+  if ((xterm = fork_xterm(&tty_fd)) < 0)
+  {
+    fprintf(stderr, "could not open xterm\n");
+    goto out;
+  }
+
+  if ((spike = fork_spike(tty_fd, argc, argv)) < 0)
+  {
+    fprintf(stderr, "could not open spike\n");
+    goto close_xterm;
+  }
+
+  while (waitpid(spike, &wait_status, 0) < 0 && !signal_exit)
+    ;
+  ret = !signal_exit && WIFEXITED(wait_status) ? WEXITSTATUS(wait_status) : -1;
+
+close_xterm:
+  kill(-xterm, SIGTERM);
+out:
+  return ret;
+}
+
+static pid_t fork_spike(int tty_fd, int argc, char** argv)
+{
+  pid_t pid = fork();
+  if (pid < 0)
+    return -1;
+
+  if (pid == 0)
+  {
+    if (dup2(tty_fd, STDIN_FILENO) < 0 || dup2(tty_fd, STDOUT_FILENO) < 0)
+      return -1;
+    execvp("spike", argv);
+    return -1;
+  }
+
+  return pid;
+}
+
+static pid_t fork_xterm(int* tty_fd)
+{
+  static const char cmd[] = "3>&1 xterm -title xspike -e sh -c 'tty 1>&3; termios-xspike'";
+
+  int fds[2];
+  if (pipe(fds) < 0)
+    return -1;
+
+  pid_t pid = fork();
+  if (pid < 0)
+    return -1;
+
+  if (pid == 0)
+  {
+    setpgid(0, 0);
+    if (dup2(fds[1], STDOUT_FILENO) < 0)
+      return -1;
+    execl("/bin/sh", "sh", "-c", cmd, NULL);
+    return -1;
+  }
+
+  char tty[NAME_MAX];
+  ssize_t ttylen = read(fds[0], tty, sizeof(tty));
+  if (ttylen <= 1 || tty[ttylen-1] != '\n')
+    return -1;
+  tty[ttylen-1] = '\0';
+  if ((*tty_fd = open(tty, O_RDWR)) < 0)
+    return -1;
+
+  return pid;
+}