RISC-V: implement terminal output for C platform.

4 files changed, 52 insertions, 7 deletions

diff --git a/riscv/riscv_platform.c b/riscv/riscv_platform.c
index fa3b49aa..5eeb0eb7 100644
--- a/riscv/riscv_platform.c
+++ b/riscv/riscv_platform.c
@@ -48,8 +48,11 @@ unit cancel_reservation(unit u)
   return UNIT;
 }
 
-unit plat_term_write(mach_bits c)
-{ return UNIT; }
+unit plat_term_write(mach_bits s)
+{ char c = s & 0xff;
+  plat_term_write_impl(c);
+  return UNIT;
+}
 
 void plat_insns_per_tick(sail_int *rop, unit u)
 { }
diff --git a/riscv/riscv_platform_impl.c b/riscv/riscv_platform_impl.c
index 3135895d..d8d52da0 100644
--- a/riscv/riscv_platform_impl.c
+++ b/riscv/riscv_platform_impl.c
@@ -1,4 +1,6 @@
 #include "riscv_platform_impl.h"
+#include <unistd.h>
+#include <stdio.h>
 
 /* Settings of the platform implementation, with common defaults. */
 
@@ -16,3 +18,11 @@ uint64_t rv_clint_size = UINT64_C(0xc0000);
 
 uint64_t rv_htif_tohost = UINT64_C(0x80001000);
 uint64_t rv_insns_per_tick = UINT64_C(100);
+
+int term_fd = 1; // set during startup
+void plat_term_write_impl(char c)
+{
+  if (write(term_fd, &c, sizeof(c)) < 0) {
+    fprintf(stderr, "Unable to write to terminal!\n");
+  }
+}
diff --git a/riscv/riscv_platform_impl.h b/riscv/riscv_platform_impl.h
index a3ab79f8..562f8554 100644
--- a/riscv/riscv_platform_impl.h
+++ b/riscv/riscv_platform_impl.h
@@ -22,3 +22,6 @@ extern uint64_t rv_clint_size;
 
 extern uint64_t rv_htif_tohost;
 extern uint64_t rv_insns_per_tick;
+
+extern int term_fd;
+void plat_term_write_impl(char c);
diff --git a/riscv/riscv_sim.c b/riscv/riscv_sim.c
index 9e99136d..fc732e89 100644
--- a/riscv/riscv_sim.c
+++ b/riscv/riscv_sim.c
@@ -1,6 +1,11 @@
 #include <getopt.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 #include "elf.h"
 #include "sail.h"
@@ -34,12 +39,13 @@ struct tv_spike_t;
 
 static bool do_dump_dts = false;
 struct tv_spike_t *s = NULL;
+char *term_log = NULL;
 
 static struct option options[] = {
   {"enable-dirty",      no_argument,       0, 'd'},
   {"enable-misaligned", no_argument,       0, 'm'},
   {"dump-dts",          no_argument,       0, 's'},
-  {"verbosity",         required_argument, 0, 'v'},
+  {"terminal-log",      required_argument, 0, 't'},
   {"help",              no_argument,       0, 'h'},
   {0, 0, 0, 0}
 };
@@ -59,7 +65,7 @@ char *process_args(int argc, char **argv)
 {
   int c, idx = 1;
   while(true) {
-    c = getopt_long(argc, argv, "dmsv:h", options, &idx);
+    c = getopt_long(argc, argv, "dmst:v:h", options, &idx);
     if (c == -1) break;
     switch (c) {
     case 'd':
@@ -71,6 +77,9 @@ char *process_args(int argc, char **argv)
     case 's':
       do_dump_dts = true;
       break;
+    case 't':
+      term_log = strdup(optarg);
+      break;
     case 'h':
       print_usage(argv[0], 0);
       break;
@@ -79,8 +88,8 @@ char *process_args(int argc, char **argv)
       print_usage(argv[0], 1);
     }
   }
-
   if (idx >= argc) print_usage(argv[0], 0);
+  if (term_log == NULL) term_log = strdup("term.log");
   return argv[idx];
 }
 
@@ -146,7 +155,7 @@ void init_sail_reset_vector(uint64_t entry)
   for (int i = 0; i < dtb_len; i++)
     write_mem(addr++, dtb[i]);
 #else
-  fprintf(stdout, "Running without rom device tree.\n");
+  fprintf(stderr, "Running without rom device tree.\n");
   /* TODO: write DTB */
 #endif
 
@@ -327,13 +336,32 @@ void run_sail(void)
   finish(diverged);
 
  step_exception:
-  fprintf(stdout, "Sail exception!");
+  fprintf(stderr, "Sail exception!");
   goto dump_state;
 }
 
+void init_logs()
+{
+#ifdef SPIKE
+  // The Spike interface uses stdout for terminal output, and stderr for logs.
+  // Do the same here.
+  int logfd;
+  if (dup2(1, 2) < 0) {
+    fprintf(stderr, "Unable to dup 1 -> 2: %s\n", strerror(errno));
+    exit(1);
+  }
+  if ((term_fd = open(term_log, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR)) < 0) {
+    fprintf(stderr, "Cannot create terminal log '%s': %s\n", term_log, strerror(errno));
+    exit(1);
+  }
+#endif
+}
+
 int main(int argc, char **argv)
 {
   char *file = process_args(argc, argv);
+  init_logs();
+
   uint64_t entry = load_sail(file);
 
   /* initialize spike before sail so that we can access the device-tree blob,
@@ -345,4 +373,5 @@ int main(int argc, char **argv)
   if (!init_check(s)) finish(1);
 
   run_sail();
+  flush_logs();
 }