=== modified file 'grub-core/net/drivers/efi/efinet.c'
--- grub-core/net/drivers/efi/efinet.c	2012-03-10 19:41:28 +0000
+++ grub-core/net/drivers/efi/efinet.c	2012-04-29 14:44:08 +0000
@@ -36,22 +36,55 @@
 {
   grub_efi_status_t st;
   grub_efi_simple_network_t *net = dev->efi_net;
-  grub_uint64_t limit_time = grub_get_time_ms () + 4000;
-  st = efi_call_7 (net->transmit, net, 0, (pack->tail - pack->data),
-		   pack->data, NULL, NULL, NULL);
-  if (st != GRUB_EFI_SUCCESS)
-    return grub_error (GRUB_ERR_IO, N_("couldn't send network packet"));
-  while (1)
+  grub_uint32_t int_status;
+  int i;
+
+  for (i = 0; i < 3; i++)
     {
+      grub_uint64_t limit_time;      
+      
+      efi_call_3 (net->get_status, net, &int_status, 0);
+
+      limit_time = grub_get_time_ms () + 5;
+      for (;;)
+	{
+	  st = efi_call_7 (net->transmit, net, 0, (pack->tail - pack->data),
+			   pack->data, NULL, NULL, NULL);
+	  if (st != GRUB_EFI_NOT_READY)
+	    break;
+
+	  if (limit_time < grub_get_time_ms ())
+	    {
+	      st = GRUB_EFI_TIMEOUT;
+	      break;
+	    }
+	}
+
+      if (st)
+	goto quit;
+
       void *txbuf = NULL;
-      st = efi_call_3 (net->get_status, net, 0, &txbuf);
-      if (st != GRUB_EFI_SUCCESS)
-	return grub_error (GRUB_ERR_IO, N_("couldn't send network packet"));
-      if (txbuf)
-	return GRUB_ERR_NONE;
-      if (limit_time < grub_get_time_ms ())
-	return grub_error (GRUB_ERR_TIMEOUT, N_("couldn't send network packet"));
+      limit_time = grub_get_time_ms () + 5;
+      for (;;)
+	{	 	  
+	  st = efi_call_3 (net->get_status, net, &int_status, &txbuf);
+
+	  if (txbuf != NULL)
+	    break;
+
+	  if (limit_time < grub_get_time_ms ())
+	    {
+	      st = GRUB_EFI_TIMEOUT;
+	      break;
+	    }
+	}
+
+    quit:
+      if (st != GRUB_EFI_TIMEOUT)
+	break;
     }
+
+  return st;
 }
 
 static struct grub_net_buff *
@@ -63,14 +96,13 @@
   grub_efi_uintn_t bufsize = 1536;
   struct grub_net_buff *nb;
 
-  nb = grub_netbuff_alloc (bufsize);
+  nb = grub_netbuff_alloc (bufsize + 2);
   if (!nb)
     return NULL;
 
   /* Reserve 2 bytes so that 2 + 14/18 bytes of ethernet header is divisible
      by 4. So that IP header is aligned on 4 bytes. */
-  grub_netbuff_reserve (nb, 2);
-  if (!nb)
+  if (grub_netbuff_reserve (nb, 2))
     {
       grub_netbuff_free (nb);
       return NULL;
@@ -84,14 +116,13 @@
 
       bufsize = ALIGN_UP (bufsize, 32);
 
-      nb = grub_netbuff_alloc (bufsize);
+      nb = grub_netbuff_alloc (bufsize + 2);
       if (!nb)
 	return NULL;
 
       /* Reserve 2 bytes so that 2 + 14/18 bytes of ethernet header is divisible
 	 by 4. So that IP header is aligned on 4 bytes. */
-      grub_netbuff_reserve (nb, 2);
-      if (!nb)
+      if (grub_netbuff_reserve (nb, 2))
 	{
 	  grub_netbuff_free (nb);
 	  return NULL;

=== modified file 'grub-core/net/tftp.c'
--- grub-core/net/tftp.c	2012-02-12 18:11:06 +0000
+++ grub-core/net/tftp.c	2012-04-29 14:31:12 +0000
@@ -27,6 +27,7 @@
 #include <grub/file.h>
 #include <grub/priority_queue.h>
 #include <grub/i18n.h>
+#include <grub/env.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -288,6 +289,7 @@
   grub_err_t err;
   grub_uint8_t *nbd;
   grub_net_network_level_address_t addr;
+  const char *block_size;
 
   data = grub_zalloc (sizeof (*data));
   if (!data)
@@ -320,9 +322,12 @@
   rrqlen += grub_strlen ("blksize") + 1;
   rrq += grub_strlen ("blksize") + 1;
 
-  grub_strcpy (rrq, "1024");
-  rrqlen += grub_strlen ("1024") + 1;
-  rrq += grub_strlen ("1024") + 1;
+  block_size = grub_env_get ("tftp_block_size");
+  if (block_size == NULL)
+    block_size = "8192";
+  grub_strcpy (rrq, block_size);
+  rrqlen += grub_strlen (block_size) + 1;
+  rrq += grub_strlen (block_size) + 1;
 
   grub_strcpy (rrq, "tsize");
   rrqlen += grub_strlen ("tsize") + 1;