Add new options into /sbin/grub, and eliminate the completion code from Stage 1.5.

grub/asmstub.c

@@ -508,11 +508,17 @@ get_diskinfo (int drive, struct geometry *geometry)
       if (! devname)
 	return -1;
 
+      if (verbose)
+	grub_printf ("Attempt to open drive 0x%x (%s)\n",
+		     drive, devname);
+	  
       /* Open read/write, or read-only if that failed. */
-      disks[drive].flags = open (devname, O_RDWR);
+      if (! read_only)
+	disks[drive].flags = open (devname, O_RDWR);
+      
       if (disks[drive].flags == -1)
 	{
-	  if (errno == EACCES || errno == EROFS)
+	  if (read_only || errno == EACCES || errno == EROFS)
 	    {
 	      disks[drive].flags = open (devname, O_RDONLY);
 	      if (disks[drive].flags == -1)
@@ -632,6 +638,55 @@ nwrite (int fd, char *buf, size_t len)
   return size;
 }
 
+/* Dump BUF in the format of hexadecimal numbers.  */
+static void
+hex_dump (void *buf, size_t size)
+{
+  /* FIXME: How to determine which length is readable?  */
+#define MAX_COLUMN	70
+
+  /* use unsigned char for numerical computations */
+  unsigned char *ptr = buf;
+  /* count the width of the line */
+  int column = 0;
+  /* how many bytes written */
+  int count = 0;
+  
+  while (size > 0)
+    {
+      /* high 4 bits */
+      int hi = *ptr >> 4;
+      /* low 4 bits */
+      int low = *ptr & 0xf;
+
+      /* grub_printf does not handle prefix number, such as %2x, so
+	 format the number by hand...  */
+      grub_printf ("%x%x", hi, low);
+      column += 2;
+      count++;
+      ptr++;
+      size--;
+
+      /* Insert space or newline with the interval 4 bytes.  */
+      if (size != 0 && (count % 4) == 0)
+	{
+	  if (column < MAX_COLUMN)
+	    {
+	      grub_printf (" ");
+	      column++;
+	    }
+	  else
+	    {
+	      grub_printf ("\n");
+	      column = 0;
+	    }
+	}
+    }
+
+  /* Add a newline at the end for readability.  */
+  grub_printf ("\n");
+}
+
 int
 biosdisk (int subfunc, int drive, struct geometry *geometry,
 	  int sector, int nsec, int segment)
@@ -669,10 +724,20 @@ biosdisk (int subfunc, int drive, struct geometry *geometry,
       if (nread (fd, buf, nsec * SECTOR_SIZE) != nsec * SECTOR_SIZE)
 	return -1;
       break;
+      
     case BIOSDISK_WRITE:
-      if (nwrite (fd, buf, nsec * SECTOR_SIZE) != nsec * SECTOR_SIZE)
-	return -1;
+      if (verbose)
+	{
+	  grub_printf ("Write %d sectors starting from %d sector"
+		       " to drive 0x%x (%s)\n",
+		       nsec, sector, drive, device_map[drive]);
+	  hex_dump (buf, nsec * SECTOR_SIZE);
+	}
+      if (! read_only)
+	if (nwrite (fd, buf, nsec * SECTOR_SIZE) != nsec * SECTOR_SIZE)
+	  return -1;
       break;
+      
     default:
       grub_printf ("unknown subfunc %d\n", subfunc);
       break;

grub/main.c

@@ -34,6 +34,8 @@ int grub_stage2 (void);
 char *program_name = 0;
 int use_config_file = 1;
 int use_curses = 1;
+int verbose = 0;
+int read_only = 0;
 static int default_boot_drive;
 static int default_install_partition;
 static char *default_config_file;
@@ -47,6 +49,8 @@ static char *default_config_file;
 #define OPT_NO_CONFIG_FILE -8
 #define OPT_NO_CURSES -9
 #define OPT_BATCH -10
+#define OPT_VERBOSE -11
+#define OPT_READ_ONLY -12
 #define OPTSTRING ""
 
 static struct option longopts[] =
@@ -60,6 +64,8 @@ static struct option longopts[] =
   {"no-config-file", no_argument, 0, OPT_NO_CONFIG_FILE},
   {"no-curses", no_argument, 0, OPT_NO_CURSES},
   {"batch", no_argument, 0, OPT_BATCH},
+  {"verbose", no_argument, 0, OPT_VERBOSE},
+  {"read-only", no_argument, 0, OPT_READ_ONLY},
   {0},
 };
 
@@ -83,6 +89,8 @@ Enter the GRand Unified Bootloader command shell.\n\
     --install-partition=PAR  specify stage2 install_partition [default=0x%x]\n\
     --no-config-file         do not use the config file\n\
     --no-curses              do not use curses\n\
+    --read-only              do not write anything to devices\n\
+    --verbose                print verbose messages\n\
     --version                print version information and exit\n\
 \n\
 Report bugs to bug-grub@gnu.org\n\
@@ -167,6 +175,14 @@ main (int argc, char **argv)
 	  use_curses = 0;
 	  break;
 
+	case OPT_READ_ONLY:
+	  read_only = 1;
+	  break;
+
+	case OPT_VERBOSE:
+	  verbose = 1;
+	  break;
+	  
 	default:
 	  usage (1);
 	}
@@ -174,6 +190,9 @@ main (int argc, char **argv)
   while (c != EOF);
 
   /* Wait until the HOLD variable is cleared by an attached debugger. */
+  if (hold && verbose)
+    grub_printf ("Run \"gdb %s %d\", and set HOLD to zero.\n",
+		 program_name, (int) getpid ());
   while (hold)
     sleep (1);