Please see my note book http://mbed.org/users/kenjiArai/notebook/freertos-on-mbed-board-with-mbed-cloud-ide--never-/

This is too old.
Below is another FreeRTOS on mbed.
http://developer.mbed.org/users/rgrover1/code/FreeRTOS/
I don't know it works well or not.
I have not evaluated it.

Revision:
0:d4960fcea8ff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FreeRTOSConfig.h	Sat Jan 01 11:17:45 2011 +0000
@@ -0,0 +1,215 @@
+/*
+    FreeRTOS V6.0.3 - Copyright (C) 2010 Real Time Engineers Ltd.
+
+    ***************************************************************************
+    *                                                                         *
+    * If you are:                                                             *
+    *                                                                         *
+    *    + New to FreeRTOS,                                                   *
+    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
+    *    + Looking for basic training,                                        *
+    *    + Wanting to improve your FreeRTOS skills and productivity           *
+    *                                                                         *
+    * then take a look at the FreeRTOS eBook                                  *
+    *                                                                         *
+    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
+    *                  http://www.FreeRTOS.org/Documentation                  *
+    *                                                                         *
+    * A pdf reference manual is also available.  Both are usually delivered   *
+    * to your inbox within 20 minutes to two hours when purchased between 8am *
+    * and 8pm GMT (although please allow up to 24 hours in case of            *
+    * exceptional circumstances).  Thank you for your support!                *
+    *                                                                         *
+    ***************************************************************************
+
+    This file is part of the FreeRTOS distribution.
+
+    FreeRTOS is free software; you can redistribute it and/or modify it under
+    the terms of the GNU General Public License (version 2) as published by the
+    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
+    ***NOTE*** The exception to the GPL is included to allow you to distribute
+    a combined work that includes FreeRTOS without being obliged to provide the
+    source code for proprietary components outside of the FreeRTOS kernel.
+    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+    more details. You should have received a copy of the GNU General Public 
+    License and the FreeRTOS license exception along with FreeRTOS; if not it 
+    can be viewed here: http://www.freertos.org/a00114.html and also obtained 
+    by writing to Richard Barry, contact details for whom are available on the
+    FreeRTOS WEB site.
+
+    1 tab == 4 spaces!
+
+    http://www.FreeRTOS.org - Documentation, latest information, license and
+    contact details.
+
+    http://www.SafeRTOS.com - A version that is certified for use in safety
+    critical systems.
+
+    http://www.OpenRTOS.com - Commercial support, development, porting,
+    licensing and training services.
+*/
+
+/*
+ *  Modified for mbed & Xpresso NXP LPC1768 board
+ *  By Kenji Arai / JH1PJL on March 9th,2010
+ *      August 1st,2010
+ */
+
+#ifndef FREERTOS_CONFIG_H
+#define FREERTOS_CONFIG_H
+
+#include "LPC17xx.h"
+
+#define portREMOVE_STATIC_QUALIFIER
+
+// Modified by  Kenji Arai / JH1PJL, August 28th,2010
+/*-----------------------------------------------------------
+ * Board Selection
+ *-----------------------------------------------------------*/
+#define USE_XPRESSO 0
+#define USE_MBED    1
+
+// Modified by  Kenji Arai / JH1PJL, September 10th,2010
+/*-----------------------------------------------------------
+ * ADC mode selection
+ *-----------------------------------------------------------*/
+#define CH_GSEN_ONLY 1
+
+// Modified by  Kenji Arai / JH1PJL, August 22nd,2010
+/*-----------------------------------------------------------
+ * AHB Memory usage
+ *-----------------------------------------------------------*/
+#define USE_AHB_RAM 1
+
+// Modified by  Kenji Arai / JH1PJL, September 18th,2010
+/*-----------------------------------------------------------
+ * Monitor interface
+ *-----------------------------------------------------------*/
+#define MON_VIA_USB    0
+#define MON_VIA_UART 1
+
+/*-----------------------------------------------------------
+ * Application specific definitions.
+ *
+ * These definitions should be adjusted for your particular hardware and
+ * application requirements.
+ *
+ * THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
+ * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
+ *----------------------------------------------------------*/
+
+#define configUSE_PREEMPTION        1
+#define configUSE_IDLE_HOOK            0
+#define configMAX_PRIORITIES        ( ( unsigned portBASE_TYPE ) 5 )
+#define configUSE_TICK_HOOK            1
+// Modified by  Kenji Arai / JH1PJL, May 2nd,2010
+#define configCPU_CLOCK_HZ            ( ( unsigned long ) 99000000 )
+//#define configCPU_CLOCK_HZ        ( ( unsigned long ) 100000000 )
+#define configTICK_RATE_HZ            ( ( portTickType ) 1000 )
+#define configMINIMAL_STACK_SIZE    ( ( unsigned short ) 64 )
+// Modified by  Kenji Arai / JH1PJL, August 13th,2010
+#define configMIN_STACK_SIZE        ( ( unsigned short ) 80 )
+#define configMID_STACK_SIZE        ( ( unsigned short ) 120 )
+#define configMAX_STACK_SIZE        ( ( unsigned short ) 180 )
+
+// Modified by  Kenji Arai / JH1PJL, May 8th,2010
+//#define configTOTAL_HEAP_SIZE        ( ( size_t ) ( 17 * 1024 ) )
+//    back to original August 18th, 2010
+//#define configTOTAL_HEAP_SIZE        ( ( size_t ) ( 19 * 1024 ) )
+//    more bigger August 18th, 2010
+#define configTOTAL_HEAP_SIZE        ( ( size_t ) ( 22 * 1024 ) )
+#define configMAX_TASK_NAME_LEN        ( 12 )
+#define configUSE_TRACE_FACILITY    1
+#define configUSE_16_BIT_TICKS        0
+#define configIDLE_SHOULD_YIELD        0
+#define configUSE_CO_ROUTINES         0
+#define configUSE_MUTEXES            1
+
+#define configMAX_CO_ROUTINE_PRIORITIES ( 2 )
+
+#define configUSE_COUNTING_SEMAPHORES     0
+#define configUSE_ALTERNATIVE_API         0
+#define configCHECK_FOR_STACK_OVERFLOW    2
+#define configUSE_RECURSIVE_MUTEXES        1
+#define configQUEUE_REGISTRY_SIZE        10
+#define configGENERATE_RUN_TIME_STATS    1
+
+/* Set the following definitions to 1 to include the API function, or zero
+to exclude the API function. */
+
+#define INCLUDE_vTaskPrioritySet            1
+#define INCLUDE_uxTaskPriorityGet            1
+#define INCLUDE_vTaskDelete                    1
+#define INCLUDE_vTaskCleanUpResources        0
+#define INCLUDE_vTaskSuspend                1
+#define INCLUDE_vTaskDelayUntil                1
+#define INCLUDE_vTaskDelay                    1
+#define INCLUDE_uxTaskGetStackHighWaterMark    1
+
+/*-----------------------------------------------------------
+ * Ethernet configuration.
+ *-----------------------------------------------------------*/
+
+/* MAC address configuration. */
+#define configMAC_ADDR0    0x00
+#define configMAC_ADDR1    0x12
+#define configMAC_ADDR2    0x13
+#define configMAC_ADDR3    0x10
+#define configMAC_ADDR4    0x15
+#define configMAC_ADDR5    0x11
+
+/* IP address configuration. */
+#define configIP_ADDR0        192
+#define configIP_ADDR1        168
+// Modified by  Kenji Arai / JH1PJL, March 9th,2010
+//#define configIP_ADDR2    0
+#define configIP_ADDR2        1
+//#define configIP_ADDR3    201
+#define configIP_ADDR3        22
+
+/* Netmask configuration. */
+#define configNET_MASK0        255
+#define configNET_MASK1        255
+#define configNET_MASK2        255
+#define configNET_MASK3        0
+
+/* Use the system definition, if there is one */
+#ifdef __NVIC_PRIO_BITS
+    #define configPRIO_BITS       __NVIC_PRIO_BITS
+#else
+    #define configPRIO_BITS       5        /* 32 priority levels */
+#endif
+
+/* The lowest priority. */
+#define configKERNEL_INTERRUPT_PRIORITY     ( 31 << (8 - configPRIO_BITS) )
+/* Priority 5, or 160 as only the top three bits are implemented. */
+#define configMAX_SYSCALL_INTERRUPT_PRIORITY     ( 5 << (8 - configPRIO_BITS) )
+
+/* Priorities passed to NVIC_SetPriority() do not require shifting as the
+function does the shifting itself.  Note these priorities need to be equal to
+or lower than configMAX_SYSCALL_INTERRUPT_PRIORITY - therefore the numeric
+value needs to be equal to or greater than 5 (on the Cortex M3 the lower the
+numeric value the higher the interrupt priority). */
+#define configEMAC_INTERRUPT_PRIORITY        5
+#define configUSB_INTERRUPT_PRIORITY        6
+
+
+/*-----------------------------------------------------------
+ * Macros required to setup the timer for the run time status.
+ *-----------------------------------------------------------*/
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern void vConfigureTimerForRunTimeStats( void );
+#ifdef __cplusplus
+}
+#endif
+//extern void vConfigureTimerForRunTimeStats( void );
+#define portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() vConfigureTimerForRunTimeStats()
+// Modified by K.Arai April 11th, 2010
+#define portGET_RUN_TIME_COUNTER_VALUE() LPC_TIM0->TC
+
+
+#endif /* FREERTOS_CONFIG_H */