2005-03-08  Nathan Sidwell  <nathan@codesourcery.com>

	* remote.c (MIN_REMOTE_PACKET_SIZE): Set to 20.
	(remote_fetch_registers): Allow uppercase hex when resyncing.
	(remote_write_bytes): Only call get_memory_write_packet_size once.
	Robustify packet size calculation for very small packets. Check
	that at least one byte will be written.

Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.176
diff -c -3 -p -r1.176 remote.c
*** remote.c	4 Mar 2005 17:52:53 -0000	1.176
--- remote.c	8 Mar 2005 11:03:32 -0000
*************** get_memory_packet_size (struct memory_pa
*** 413,421 ****
  #ifndef MAX_REMOTE_PACKET_SIZE
  #define MAX_REMOTE_PACKET_SIZE 16384
  #endif
!   /* NOTE: 16 is just chosen at random.  */
  #ifndef MIN_REMOTE_PACKET_SIZE
! #define MIN_REMOTE_PACKET_SIZE 16
  #endif
    long what_they_get;
    if (config->fixed_p)
--- 413,421 ----
  #ifndef MAX_REMOTE_PACKET_SIZE
  #define MAX_REMOTE_PACKET_SIZE 16384
  #endif
!   /* NOTE: 20 ensures we can write at least one byte.  */
  #ifndef MIN_REMOTE_PACKET_SIZE
! #define MIN_REMOTE_PACKET_SIZE 20
  #endif
    long what_they_get;
    if (config->fixed_p)
*************** remote_fetch_registers (int regnum)
*** 3332,3337 ****
--- 3332,3338 ----
       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')
  	 && (buf[0] < 'a' || buf[0] > 'f')
  	 && buf[0] != 'x')	/* New: unavailable register value.  */
      {
*************** remote_write_bytes (CORE_ADDR memaddr, c
*** 3659,3674 ****
    /* Verify that the target can support a binary download.  */
    check_binary_download (memaddr);
  
    /* Compute the size, and then allocate space for the largest
!      possible packet.  Include space for an extra trailing NULL.  */
!   sizeof_buf = get_memory_write_packet_size () + 1;
    buf = alloca (sizeof_buf);
  
    /* Compute the size of the actual payload by subtracting out the
!      packet header and footer overhead: "$M<memaddr>,<len>:...#nn".  */
!   payload_size = (get_memory_write_packet_size () - (strlen ("$M,:#NN")
! 						     + hexnumlen (memaddr)
! 						     + hexnumlen (len)));
  
    /* Construct the packet header: "[MX]<memaddr>,<len>:".   */
  
--- 3660,3677 ----
    /* Verify that the target can support a binary download.  */
    check_binary_download (memaddr);
  
+   payload_size = get_memory_write_packet_size ();
+   
    /* Compute the size, and then allocate space for the largest
!      possible packet.  Include space for an extra trailing NUL.  */
!   sizeof_buf = payload_size + 1;
    buf = alloca (sizeof_buf);
  
    /* Compute the size of the actual payload by subtracting out the
!      packet header and footer overhead: "$M<memaddr>,<len>:...#nn".
!      */
!   payload_size -= strlen ("$M,:#NN");
!   payload_size -= hexnumlen (memaddr);
  
    /* Construct the packet header: "[MX]<memaddr>,<len>:".   */
  
*************** remote_write_bytes (CORE_ADDR memaddr, c
*** 3681,3691 ****
--- 3684,3698 ----
        *p++ = 'X';
        /* Best guess at number of bytes that will fit.  */
        todo = min (len, payload_size);
+       payload_size -= hexnumlen (todo);
+       todo = min (todo, payload_size);
        break;
      case PACKET_DISABLE:
        *p++ = 'M';
        /* Num bytes that will fit.  */
        todo = min (len, payload_size / 2);
+       payload_size -= hexnumlen (todo);
+       todo = min (todo, payload_size / 2);
        break;
      case PACKET_SUPPORT_UNKNOWN:
        internal_error (__FILE__, __LINE__,
*************** remote_write_bytes (CORE_ADDR memaddr, c
*** 3693,3698 ****
--- 3700,3708 ----
      default:
        internal_error (__FILE__, __LINE__, _("bad switch"));
      }
+   if (todo <= 0)
+     internal_error (__FILE__, __LINE__,
+ 		    _("minumum packet size too small to write data"));
  
    /* Append "<memaddr>".  */
    memaddr = remote_address_masked (memaddr);