fix the cortex-m3 context switch bug when interrupt preempts pendsv exception; add RT_LWIP_ETH_PAD_SIZE option; fix device activate flag set issue in init function.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@193 bbd45198-f89e-11dd-88c7-29a3b14d5316

src/device.c

@@ -83,6 +83,10 @@ rt_err_t rt_device_init_all()
 			{
 				rt_kprintf("init device:%s error:\n", device->parent.name);
 				rt_kprintf("error code:%d\n", result);
+			}
+			else
+			{
+				device->flag |= RT_DEVICE_FLAG_ACTIVATED;
 			}
 		}
 	}

src/mem.c

@@ -318,7 +318,7 @@ void *rt_malloc(rt_size_t size)
 
 #ifdef RT_USING_HOOK
 			if (rt_malloc_hook != RT_NULL)
-				rt_malloc_hook((rt_uint8_t*)mem, size);
+				rt_malloc_hook((rt_uint8_t *)mem + SIZEOF_STRUCT_MEM, size);
 #endif
 			/* return the memory data except mem struct */
 			return (rt_uint8_t *)mem + SIZEOF_STRUCT_MEM;