[rtems commit] bsp/genmcf548x: Enable FPU in BSP startup code

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    6d136ed9dd9eb3a5929d18e5c7f37b5265a35f11
Changeset: http://git.rtems.org/rtems/commit/?id=6d136ed9dd9eb3a5929d18e5c7f37b5265a35f11

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Fri Apr 20 14:03:39 2012 +0200

bsp/genmcf548x: Enable FPU in BSP startup code

---

 .../lib/libbsp/m68k/genmcf548x/startup/bspstart.c  |   18 +++++-------------
 1 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/c/src/lib/libbsp/m68k/genmcf548x/startup/bspstart.c b/c/src/lib/libbsp/m68k/genmcf548x/startup/bspstart.c
index 743ad4c..9de5d56 100644
--- a/c/src/lib/libbsp/m68k/genmcf548x/startup/bspstart.c
+++ b/c/src/lib/libbsp/m68k/genmcf548x/startup/bspstart.c
@@ -70,8 +70,10 @@ extern char WorkAreaBase [];
 #define m68k_set_acr3(_acr3) __asm__ volatile ("movec %0,#0x0007" : : "d" (_acr3))
 
 /*
- * Set initial cacr mode, mainly enables branch/intruction/data cache and
- * switch off FPU.
+ * Set initial CACR mode, mainly enables branch/instruction/data cache.  The
+ * FPU must be switched on in the BSP startup code since the
+ * _Thread_Start_multitasking() will restore the floating-point context of the
+ * initialization task if necessary.
  */
 static const uint32_t BSP_CACR_INIT = MCF548X_CACR_DEC /* enable data cache */
   | MCF548X_CACR_BEC /* enable branch cache */
@@ -80,8 +82,7 @@ static const uint32_t BSP_CACR_INIT = MCF548X_CACR_DEC /* enable data cache */
       /* set data cache mode to write-through */
   | MCF548X_CACR_DESB /* enable data store buffer */
   | MCF548X_CACR_DDSP /* data access only in supv. mode */
-  | MCF548X_CACR_IDSP /* instr. access only in supv. mode */
-  | MCF548X_CACR_DF; /* disable FPU */
+  | MCF548X_CACR_IDSP; /* instr. access only in supv. mode */
 
 /*
  * CACR maintenance functions
@@ -273,15 +274,6 @@ void bsp_start( void )
   /* Initialize CACR shadow register */
   _CPU_cacr_shadow = BSP_CACR_INIT;
 
-  /* Switch on FPU in CACR shadow register if necessary */
-  if ((Configuration_POSIX_API.number_of_initialization_threads > 0) ||
-      ((Configuration_RTEMS_API.number_of_initialization_tasks > 0) &&
-       (Configuration_RTEMS_API.User_initialization_tasks_table
-	->attribute_set & RTEMS_FLOATING_POINT) != 0)
-      ) {
-    _CPU_cacr_shadow &= ~MCF548X_CACR_DF;
-  }
-
   /*
    * Load the shadow variable of CACR with initial mode and write it to the
    * CACR.  Interrupts are still disabled, so there is no need for surrounding