This floating point unit is available in Cortex-M4F processors and
defined by ARMv7-M. This adds basic support for other VFP-D16 variants.
---
c/src/lib/libbsp/arm/shared/start/start.S | 20 ++++++++++++++
cpukit/score/cpu/arm/arm-context-validate.S | 31 +++++++++++++---------
.../score/cpu/arm/arm-context-volatile-clobber.S | 8 +++---
cpukit/score/cpu/arm/arm_exc_interrupt.S | 12 ++++++---
cpukit/score/cpu/arm/armv4-exception-default.S | 6 +++--
cpukit/score/cpu/arm/armv7m-context-switch.c | 13 +++++++--
cpukit/score/cpu/arm/armv7m-isr-dispatch.c | 30 +++++++++++++++++----
cpukit/score/cpu/arm/cpu.c | 2 +-
cpukit/score/cpu/arm/cpu_asm.S | 4 +--
cpukit/score/cpu/arm/rtems/score/arm.h | 17 +++++++++---
cpukit/score/cpu/arm/rtems/score/armv7m.h | 22 ++++++++++++++-
cpukit/score/cpu/arm/rtems/score/cpu.h | 8 +++---
12 files changed, 133 insertions(+), 40 deletions(-)
diff --git a/c/src/lib/libbsp/arm/shared/start/start.S
b/c/src/lib/libbsp/arm/shared/start/start.S
index 096e9bd..8c73b8d 100644
--- a/c/src/lib/libbsp/arm/shared/start/start.S
+++ b/c/src/lib/libbsp/arm/shared/start/start.S
@@ -300,6 +300,26 @@ bsp_start_vector_table_end:
_start:
+#ifdef ARM_MULTILIB_VFP
+ /* CPACR is located at address 0xe000ed88 */
+ ldr.w r0, =0xe000ed88
+
+ /* Read CPACR */
+ ldr r1, [r0]
+
+ /* Set bits 20-23 to enable CP10 and CP11 co-processors */
+ orr r1, r1, #(0xf << 20)
+
+ /* Write back the modified value to the CPACR */
+ str r1, [r0]
+
+ /* Wait for store to complete */
+ dsb
+
+ /* Reset pipeline now the FPU is enabled */
+ isb
+#endif
+
ldr sp, =bsp_stack_main_end
ldr lr, =bsp_start_hook_0_done + 1
b bsp_start_hook_0
diff --git a/cpukit/score/cpu/arm/arm-context-validate.S
b/cpukit/score/cpu/arm/arm-context-validate.S
index f2772b4..fdfb6c1 100644
--- a/cpukit/score/cpu/arm/arm-context-validate.S
+++ b/cpukit/score/cpu/arm/arm-context-validate.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013 embedded brains GmbH. All rights reserved.
+ * Copyright (c) 2013-2014 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
@@ -29,7 +29,7 @@
#define FRAME_OFFSET_R11 28
#define FRAME_OFFSET_LR 32
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
#define FRAME_OFFSET_D8 40
#define FRAME_OFFSET_D9 48
#define FRAME_OFFSET_D10 56
@@ -71,7 +71,7 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_validate)
mov r1, lr
str r1, [sp, #FRAME_OFFSET_LR]
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
vstr d8, [sp, #FRAME_OFFSET_D8]
vstr d9, [sp, #FRAME_OFFSET_D9]
vstr d10, [sp, #FRAME_OFFSET_D10]
@@ -96,11 +96,15 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_validate)
.endm
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
/* R3 contains the FPSCR */
vmrs r3, FPSCR
movs r4, #0x001f
+#ifdef ARM_MULTILIB_ARCH_V7M
+ movt r4, #0xf000
+#else
movt r4, #0xf800
+#endif
bic r3, r3, r4
and r4, r4, r0
orr r3, r3, r4
@@ -120,7 +124,7 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_validate)
fill_register r12
fill_register lr
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
.macro fill_vfp_register reg
add r1, r1, #1
vmov \reg, r1, r1
@@ -142,6 +146,7 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_validate)
fill_vfp_register d13
fill_vfp_register d14
fill_vfp_register d15
+#ifdef ARM_MULTILIB_VFP_D32
fill_vfp_register d16
fill_vfp_register d17
fill_vfp_register d18
@@ -158,7 +163,8 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_validate)
fill_vfp_register d29
fill_vfp_register d30
fill_vfp_register d31
-#endif
+#endif /* ARM_MULTILIB_VFP_D32 */
+#endif /* ARM_MULTILIB_VFP */
/* Check */
check:
@@ -174,7 +180,7 @@ check:
mov r1, r0
-#ifndef ARM_MULTILIB_VFP_D32
+#ifndef ARM_MULTILIB_VFP
check_register r3
#endif
@@ -189,7 +195,7 @@ check:
check_register r12
check_register lr
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
b check_vfp
#endif
@@ -217,7 +223,7 @@ restore:
ldr r1, [sp, #FRAME_OFFSET_LR]
mov lr, r1
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
vldr d8, [sp, #FRAME_OFFSET_D8]
vldr d9, [sp, #FRAME_OFFSET_D9]
vldr d10, [sp, #FRAME_OFFSET_D10]
@@ -234,7 +240,7 @@ restore:
FUNCTION_END(_CPU_Context_validate)
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
check_vfp:
.macro check_vfp_register reg
@@ -270,6 +276,7 @@ check_vfp:
check_vfp_register d13
check_vfp_register d14
check_vfp_register d15
+#ifdef ARM_MULTILIB_VFP_D32
check_vfp_register d16
check_vfp_register d17
check_vfp_register d18
@@ -286,6 +293,7 @@ check_vfp:
check_vfp_register d29
check_vfp_register d30
check_vfp_register d31
+#endif /* ARM_MULTILIB_VFP_D32 */
/* Restore r4 and r5 */
mov r1, r0
@@ -293,5 +301,4 @@ check_vfp:
fill_register r5
b check
-
-#endif
+#endif /* ARM_MULTILIB_VFP */
diff --git a/cpukit/score/cpu/arm/arm-context-volatile-clobber.S
b/cpukit/score/cpu/arm/arm-context-volatile-clobber.S
index 459acba..7970b8e 100644
--- a/cpukit/score/cpu/arm/arm-context-volatile-clobber.S
+++ b/cpukit/score/cpu/arm/arm-context-volatile-clobber.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013 embedded brains GmbH. All rights reserved.
+ * Copyright (c) 2013-2014 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
@@ -27,7 +27,7 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_volatile_clobber)
mov \reg, r0
.endm
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
vmrs r1, FPSCR
movs r2, #0x001f
movt r2, #0xf800
@@ -49,6 +49,7 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_volatile_clobber)
clobber_vfp_register d5
clobber_vfp_register d6
clobber_vfp_register d7
+#ifdef ARM_MULTILIB_VFP_D32
clobber_vfp_register d16
clobber_vfp_register d17
clobber_vfp_register d18
@@ -65,7 +66,8 @@ FUNCTION_THUMB_ENTRY(_CPU_Context_volatile_clobber)
clobber_vfp_register d29
clobber_vfp_register d30
clobber_vfp_register d31
-#endif
+#endif /* ARM_MULTILIB_VFP_D32 */
+#endif /* ARM_MULTILIB_VFP */
clobber_register r1
clobber_register r2
diff --git a/cpukit/score/cpu/arm/arm_exc_interrupt.S
b/cpukit/score/cpu/arm/arm_exc_interrupt.S
index e8026c8..7930c32 100644
--- a/cpukit/score/cpu/arm/arm_exc_interrupt.S
+++ b/cpukit/score/cpu/arm/arm_exc_interrupt.S
@@ -75,13 +75,15 @@ _ARMV4_Exception_interrupt:
stmdb sp!, CONTEXT_LIST
stmdb sp!, {SP_OF_INTERRUPTED_CONTEXT, lr}
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
/* Save VFP context */
vmrs r0, FPSCR
vstmdb sp!, {d0-d7}
+#ifdef ARM_MULTILIB_VFP_D32
vstmdb sp!, {d16-d31}
- stmdb sp!, {r0, r1}
#endif
+ stmdb sp!, {r0, r1}
+#endif /* ARM_MULTILIB_VFP */
/* Get per-CPU control of current processor */
GET_SELF_CPU_CONTROL SELF_CPU_CONTROL, r1
@@ -166,13 +168,15 @@ thread_dispatch_done:
/* Switch to ARM instructions if necessary */
SWITCH_FROM_THUMB_TO_ARM
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
/* Restore VFP context */
ldmia sp!, {r0, r1}
+#ifdef ARM_MULTILIB_VFP_D32
vldmia sp!, {d16-d31}
+#endif
vldmia sp!, {d0-d7}
vmsr FPSCR, r0
-#endif
+#endif /* ARM_MULTILIB_VFP */
/* Restore SP_OF_INTERRUPTED_CONTEXT register and link register */
ldmia sp!, {SP_OF_INTERRUPTED_CONTEXT, lr}
diff --git a/cpukit/score/cpu/arm/armv4-exception-default.S
b/cpukit/score/cpu/arm/armv4-exception-default.S
index 950ad67..8a97320 100644
--- a/cpukit/score/cpu/arm/armv4-exception-default.S
+++ b/cpukit/score/cpu/arm/armv4-exception-default.S
@@ -118,7 +118,7 @@ save_more_context:
/* Argument for high level handler */
mov r0, sp
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
/* Ensure that the FPU is enabled */
vmrs r1, FPEXC
tst r1, #(1 << 30)
@@ -132,10 +132,12 @@ save_more_context:
vmrs r2, FPSCR
stmia r4!, {r1-r2}
vstmia r4!, {d0-d15}
+#ifdef ARM_MULTILIB_VFP_D32
vstmia r4!, {d16-d31}
+#endif
fpu_save_done:
-#endif
+#endif /* ARM_MULTILIB_VFP */
/* Call high level handler */
SWITCH_FROM_ARM_TO_THUMB r1
diff --git a/cpukit/score/cpu/arm/armv7m-context-switch.c
b/cpukit/score/cpu/arm/armv7m-context-switch.c
index eabf2c8..359a1a7 100644
--- a/cpukit/score/cpu/arm/armv7m-context-switch.c
+++ b/cpukit/score/cpu/arm/armv7m-context-switch.c
@@ -5,7 +5,7 @@
*/
/*
- * Copyright (c) 2011 Sebastian Huber. All rights reserved.
+ * Copyright (c) 2011-2014 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
@@ -37,17 +37,26 @@ void __attribute__((naked)) _CPU_Context_switch(
"movt r2, #:upper16:_Per_CPU_Information\n"
"ldr r3, [r2, %[isrpcpuoff]]\n"
"stm r0, {r4-r11, lr}\n"
+#ifdef ARM_MULTILIB_VFP
+ "add r4, r0, %[d8off]\n"
+ "vstm r4, {d8-d15}\n"
+#endif
"str sp, [r0, %[spctxoff]]\n"
"str r3, [r0, %[isrctxoff]]\n"
"ldr r3, [r1, %[isrctxoff]]\n"
"ldr sp, [r1, %[spctxoff]]\n"
+#ifdef ARM_MULTILIB_VFP
+ "add r4, r1, %[d8off]\n"
+ "vldm r4, {d8-d15}\n"
+#endif
"ldm r1, {r4-r11, lr}\n"
"str r3, [r2, %[isrpcpuoff]]\n"
"bx lr\n"
:
: [spctxoff] "J" (offsetof(Context_Control, register_sp)),
[isrctxoff] "J" (offsetof(Context_Control, isr_nest_level)),
- [isrpcpuoff] "J" (offsetof(Per_CPU_Control, isr_nest_level))
+ [isrpcpuoff] "J" (offsetof(Per_CPU_Control, isr_nest_level)),
+ [d8off] "J" (ARM_CONTEXT_CONTROL_D8_OFFSET)
);
}
diff --git a/cpukit/score/cpu/arm/armv7m-isr-dispatch.c
b/cpukit/score/cpu/arm/armv7m-isr-dispatch.c
index 048ffa8..e460e9c 100644
--- a/cpukit/score/cpu/arm/armv7m-isr-dispatch.c
+++ b/cpukit/score/cpu/arm/armv7m-isr-dispatch.c
@@ -5,7 +5,7 @@
*/
/*
- * Copyright (c) 2011 Sebastian Huber. All rights reserved.
+ * Copyright (c) 2011-2014 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
@@ -37,13 +37,27 @@ static void __attribute__((naked)) _ARMV7M_Thread_dispatch(
void )
);
}
+static void _ARMV7M_Trigger_lazy_floating_point_context_save( void )
+{
+#ifdef ARM_MULTILIB_VFP
+ __asm__ volatile (
+ "vmov.f32 s0, s0\n"
+ );
+#endif
+}
+
void _ARMV7M_Pendable_service_call( void )
{
+ ARMV7M_Exception_frame *ef;
+
_ISR_Nest_level = 1;
+
_ARMV7M_SCB->icsr = ARMV7M_SCB_ICSR_PENDSVCLR;
- ARMV7M_Exception_frame *ef = (ARMV7M_Exception_frame *) _ARMV7M_Get_PSP();
+ _ARMV7M_Trigger_lazy_floating_point_context_save();
+
+ ef = (ARMV7M_Exception_frame *) _ARMV7M_Get_PSP();
--ef;
- _ARMV7M_Set_PSP((uint32_t) ef);
+ _ARMV7M_Set_PSP( (uint32_t) ef );
/*
* According to "ARMv7-M Architecture Reference Manual" section B1.5.6
@@ -57,11 +71,17 @@ void _ARMV7M_Pendable_service_call( void )
void _ARMV7M_Supervisor_call( void )
{
- ARMV7M_Exception_frame *ef = (ARMV7M_Exception_frame *) _ARMV7M_Get_PSP();
+ ARMV7M_Exception_frame *ef;
+
+ _ARMV7M_Trigger_lazy_floating_point_context_save();
+
+ ef = (ARMV7M_Exception_frame *) _ARMV7M_Get_PSP();
++ef;
- _ARMV7M_Set_PSP((uint32_t) ef);
+ _ARMV7M_Set_PSP( (uint32_t) ef );
+
_ISR_Nest_level = 0;
RTEMS_COMPILER_MEMORY_BARRIER();
+
if ( _Thread_Dispatch_necessary ) {
_ARMV7M_Pendable_service_call();
}
diff --git a/cpukit/score/cpu/arm/cpu.c b/cpukit/score/cpu/arm/cpu.c
index 089826e..9942c4a 100644
--- a/cpukit/score/cpu/arm/cpu.c
+++ b/cpukit/score/cpu/arm/cpu.c
@@ -35,7 +35,7 @@
#include <rtems/score/tls.h>
#include <rtems/score/cpu.h>
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
RTEMS_STATIC_ASSERT(
offsetof( Context_Control, register_d8 ) == ARM_CONTEXT_CONTROL_D8_OFFSET,
ARM_CONTEXT_CONTROL_D8_OFFSET
diff --git a/cpukit/score/cpu/arm/cpu_asm.S b/cpukit/score/cpu/arm/cpu_asm.S
index d4355b4..344512b 100644
--- a/cpukit/score/cpu/arm/cpu_asm.S
+++ b/cpukit/score/cpu/arm/cpu_asm.S
@@ -58,7 +58,7 @@ DEFINE_FUNCTION_ARM(_CPU_Context_switch)
mrs r2, CPSR
stmia r0, {r2, r4, r5, r6, r7, r8, r9, r10, r11, r13, r14}
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
add r3, r0, #ARM_CONTEXT_CONTROL_D8_OFFSET
vstm r3, {d8-d15}
#endif
@@ -101,7 +101,7 @@ DEFINE_FUNCTION_ARM(_CPU_Context_switch)
mcr p15, 0, r3, c13, c0, 3
#endif
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
add r3, r1, #ARM_CONTEXT_CONTROL_D8_OFFSET
vldm r3, {d8-d15}
#endif
diff --git a/cpukit/score/cpu/arm/rtems/score/arm.h
b/cpukit/score/cpu/arm/rtems/score/arm.h
index a105f17..586a8cb 100644
--- a/cpukit/score/cpu/arm/rtems/score/arm.h
+++ b/cpukit/score/cpu/arm/rtems/score/arm.h
@@ -50,10 +50,19 @@ extern "C" {
#define ARM_MULTILIB_HAS_THREAD_ID_REGISTER
#endif
-#if defined(__ARM_NEON__)
- #define ARM_MULTILIB_VFP_D32
-#elif !defined(__SOFTFP__)
- #error "FPU support not implemented"
+#if !defined(__SOFTFP__)
+ #if defined(__ARM_NEON__)
+ #define ARM_MULTILIB_VFP_D32
+ #elif defined(__VFP_FP__)
+ #define ARM_MULTILIB_VFP_D16
+ #else
+ #error "FPU support not implemented"
+ #endif
+#endif
+
+#if defined(ARM_MULTILIB_VFP_D16) \
+ || defined(ARM_MULTILIB_VFP_D32)
+ #define ARM_MULTILIB_VFP
#endif
/*
diff --git a/cpukit/score/cpu/arm/rtems/score/armv7m.h
b/cpukit/score/cpu/arm/rtems/score/armv7m.h
index b545859..c1f820b 100644
--- a/cpukit/score/cpu/arm/rtems/score/armv7m.h
+++ b/cpukit/score/cpu/arm/rtems/score/armv7m.h
@@ -5,7 +5,7 @@
*/
/*
- * Copyright (c) 2011 Sebastian Huber. All rights reserved.
+ * Copyright (c) 2011-2014 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
@@ -47,6 +47,26 @@ typedef struct {
void *register_lr;
void *register_pc;
uint32_t register_xpsr;
+#ifdef ARM_MULTILIB_VFP
+ uint32_t register_s0;
+ uint32_t register_s1;
+ uint32_t register_s2;
+ uint32_t register_s3;
+ uint32_t register_s4;
+ uint32_t register_s5;
+ uint32_t register_s6;
+ uint32_t register_s7;
+ uint32_t register_s8;
+ uint32_t register_s9;
+ uint32_t register_s10;
+ uint32_t register_s11;
+ uint32_t register_s12;
+ uint32_t register_s13;
+ uint32_t register_s14;
+ uint32_t register_s15;
+ uint32_t register_fpscr;
+ uint32_t reserved;
+#endif
} ARMV7M_Exception_frame;
typedef struct {
diff --git a/cpukit/score/cpu/arm/rtems/score/cpu.h
b/cpukit/score/cpu/arm/rtems/score/cpu.h
index ad070df..089fc27 100644
--- a/cpukit/score/cpu/arm/rtems/score/cpu.h
+++ b/cpukit/score/cpu/arm/rtems/score/cpu.h
@@ -8,7 +8,7 @@
* This include file contains information pertaining to the ARM
* processor.
*
- * Copyright (c) 2009-2013 embedded brains GmbH.
+ * Copyright (c) 2009-2014 embedded brains GmbH.
*
* Copyright (c) 2007 Ray Xu <rayx...@gmail.com>
*
@@ -212,12 +212,12 @@
#define ARM_CONTEXT_CONTROL_THREAD_ID_OFFSET 44
#endif
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
#define ARM_CONTEXT_CONTROL_D8_OFFSET 48
#endif
#ifdef RTEMS_SMP
- #ifdef ARM_MULTILIB_VFP_D32
+ #ifdef ARM_MULTILIB_VFP
#define ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET 112
#else
#define ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET 48
@@ -278,7 +278,7 @@ typedef struct {
#ifdef ARM_MULTILIB_HAS_THREAD_ID_REGISTER
uint32_t thread_id;
#endif
-#ifdef ARM_MULTILIB_VFP_D32
+#ifdef ARM_MULTILIB_VFP
uint64_t register_d8;
uint64_t register_d9;
uint64_t register_d10;
--
1.8.1.4
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