RTX: Support stacks larger than 64k

Cherry pick commit d587474 -
"RTX: Support stacks larger than 64k"

This allows the latest version of the RTOS to run mbed client over
ethernet without crashing.

Author: c1728p9

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M0/TOOLCHAIN_GCC/HAL_CM0.S

@@ -35,7 +35,7 @@
         .file   "HAL_CM0.S"
         .syntax unified
 
-        .equ    TCB_TSTACK, 40
+        .equ    TCB_TSTACK, 44
 
 
 /*----------------------------------------------------------------------------

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M0/TOOLCHAIN_IAR/HAL_CM0.S

@@ -34,7 +34,7 @@
 
         NAME    HAL_CM0.S
 
-        #define TCB_TSTACK 40
+        #define TCB_TSTACK 44
 
         EXTERN  os_flags
         EXTERN  os_tsk

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M0P/TOOLCHAIN_GCC/HAL_CM0.S

@@ -35,7 +35,7 @@
         .file   "HAL_CM0.S"
         .syntax unified
 
-        .equ    TCB_TSTACK, 40
+        .equ    TCB_TSTACK, 44
 
 
 /*----------------------------------------------------------------------------

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M0P/TOOLCHAIN_IAR/HAL_CM0.S

@@ -34,7 +34,7 @@
 
         NAME    HAL_CM0.S
 
-        #define TCB_TSTACK 40
+        #define TCB_TSTACK 44
 
         EXTERN  os_flags
         EXTERN  os_tsk

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M3/TOOLCHAIN_GCC/HAL_CM3.S

@@ -35,7 +35,7 @@
         .file   "HAL_CM3.S"
         .syntax unified
 
-        .equ    TCB_TSTACK, 40
+        .equ    TCB_TSTACK, 44
 
 
 /*----------------------------------------------------------------------------

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_M3/TOOLCHAIN_IAR/HAL_CM3.S

@@ -34,7 +34,7 @@
 
         NAME    HAL_CM3.S
 
-        #define TCB_TSTACK 40
+        #define TCB_TSTACK 44
 
         EXTERN  os_flags
         EXTERN  os_tsk

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_RTOS_M4_M7/TOOLCHAIN_GCC/HAL_CM4.S

@@ -36,7 +36,7 @@
         .syntax unified
 
         .equ    TCB_STACKF, 37
-        .equ    TCB_TSTACK, 40
+        .equ    TCB_TSTACK, 44
 
 
 /*----------------------------------------------------------------------------

libraries/rtos/rtx/TARGET_CORTEX_M/TARGET_RTOS_M4_M7/TOOLCHAIN_IAR/HAL_CM4.S

@@ -35,7 +35,7 @@
         NAME    HAL_CM4.S
 
         #define TCB_STACKF 37
-        #define TCB_TSTACK 40
+        #define TCB_TSTACK 44
 
         EXTERN  os_flags
         EXTERN  os_tsk

libraries/rtos/rtx/TARGET_CORTEX_M/rt_Task.c

@@ -233,7 +233,7 @@ OS_TID rt_tsk_create (FUNCP task, U32 prio_stksz, void *stk, void *argv) {
   }
   /* If "size != 0" use a private user provided stack. */
   task_context->stack      = stk;
-  task_context->priv_stack = (U16)(prio_stksz >> 8);
+  task_context->priv_stack = prio_stksz >> 8;
   /* Pass parameter 'argv' to 'rt_init_context' */
   task_context->msg = argv;
   /* For 'size == 0' system allocates the user stack from the memory pool. */

libraries/rtos/rtx/TARGET_CORTEX_M/rt_TypeDef.h

@@ -71,16 +71,17 @@ typedef struct OS_TCB {
 
   /* Hardware dependant part: specific for CM processor                      */
   U8     stack_frame;             /* Stack frame: 0=Basic, 1=Extended,       */
+  U16    reserved;                /* Two reserved bytes for alignment        */
                                   /* (2=VFP/D16 stacked, 4=NEON/D32 stacked) */
-  U16    priv_stack;              /* Private stack size, 0= system assigned  */
+  U32    priv_stack;              /* Private stack size, 0= system assigned  */
   U32    tsk_stack;               /* Current task Stack pointer (R13)        */
   U32    *stack;                  /* Pointer to Task Stack memory block      */
 
   /* Task entry point used for uVision debugger                              */
   FUNCP  ptask;                   /* Task entry address                      */
 } *P_TCB;
 #define TCB_STACKF      37        /* 'stack_frame' offset                    */
-#define TCB_TSTACK      40        /* 'tsk_stack' offset                      */
+#define TCB_TSTACK      44        /* 'tsk_stack' offset                      */
 
 typedef struct OS_PSFE {          /* Post Service Fifo Entry                 */
   void  *id;                      /* Object Identification                   */