/************************************************************************************
* arch/arm/src/armv7-m/up_fpu.S
*
* Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
/*
* When this file is assembled, it will require the following GCC options:
*
* -mcpu=cortex-m3 -mfloat-abi=hard -mfpu=vfp -meabi=5
*/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <arch/irq.h>
#ifdef CONFIG_ARCH_FPU
/************************************************************************************
* Preprocessor Definitions
************************************************************************************/
/************************************************************************************
* Global Symbols
************************************************************************************/
.globl up_savefpu
.globl up_restorefpu
.syntax unified
.thumb
.file "up_fpu.S"
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: up_savefpu
*
* Description:
* Given the pointer to a register save area (in R0), save the state of the
* floating point registers.
*
* C Function Prototype:
* void up_savefpu(uint32_t *regs);
*
* Input Parameters:
* regs - A pointer to the register save area in which to save the floating point
* registers
*
* Returned Value:
* None
*
************************************************************************************/
.thumb_func
.type up_savefpu, function
up_savefpu:
add r1, r0, #(4*REG_S0) /* R1=Address of FP register storage */
/* Some older GNU assemblers don't support all the newer UAL mnemonics. */
#if 1 /* Use UAL mnemonics */
/* Store all floating point registers. Registers are stored in numeric order,
* s0, s1, ... in increasing address order.
*/
vstmia r1!, {s0-s31} /* Save the full FP context */
/* Store the floating point control and status register. At the end of the
* vstmia, r1 will point to the FPCSR storage location.
*/
vmrs r2, fpscr /* Fetch the FPCSR */
str r2, [r1], #4 /* Save the floating point control and status register */
#else
/* Store all floating point registers */
#if 1 /* Use store multiple */
fstmias r1!, {s0-s31} /* Save the full FP context */
#else
vmov r2, r3, d0 /* r2, r3 = d0 */
str r2, [r1], #4 /* Save S0 and S1 values */
str r3, [r1], #4
vmov r2, r3, d1 /* r2, r3 = d1 */
str r2, [r1], #4 /* Save S2 and S3 values */
str r3, [r1], #4
vmov r2, r3, d2 /* r2, r3 = d2 */
str r2, [r1], #4 /* Save S4 and S5 values */
str r3, [r1], #4
vmov r2, r3, d3 /* r2, r3 = d3 */
str r2, [r1], #4 /* Save S6 and S7 values */
str r3, [r1], #4
vmov r2, r3, d4 /* r2, r3 = d4 */
str r2, [r1], #4 /* Save S8 and S9 values */
str r3, [r1], #4
vmov r2, r3, d5 /* r2, r3 = d5 */
str r2, [r1], #4 /* Save S10 and S11 values */
str r3, [r1], #4
vmov r2, r3, d6 /* r2, r3 = d6 */
str r2, [r1], #4 /* Save S12 and S13 values */
str r3, [r1], #4
vmov r2, r3, d7 /* r2, r3 = d7 */
str r2, [r1], #4 /* Save S14 and S15 values */
str r3, [r1], #4
vmov r2, r3, d8 /* r2, r3 = d8 */
str r2, [r1], #4 /* Save S16 and S17 values */
str r3, [r1], #4
vmov r2, r3, d9 /* r2, r3 = d9 */
str r2, [r1], #4 /* Save S18 and S19 values */
str r3, [r1], #4
vmov r2, r3, d10 /* r2, r3 = d10 */
str r2, [r1], #4 /* Save S20 and S21 values */
str r3, [r1], #4
vmov r2, r3, d11 /* r2, r3 = d11 */
str r2, [r1], #4 /* Save S22 and S23 values */
str r3, [r1], #4
vmov r2, r3, d12 /* r2, r3 = d12 */
str r2, [r1], #4 /* Save S24 and S25 values */
str r3, [r1], #4
vmov r2, r3, d13 /* r2, r3 = d13 */
str r2, [r1], #4 /* Save S26 and S27 values */
str r3, [r1], #4
vmov r2, r3, d14 /* r2, r3 = d14 */
str r2, [r1], #4 /* Save S28 and S29 values */
str r3, [r1], #4
vmov r2, r3, d15 /* r2, r3 = d15 */
str r2, [r1], #4 /* Save S30 and S31 values */
str r3, [r1], #4
#endif
/* Store the floating point control and status register */
fmrx r2, fpscr /* Fetch the FPCSR */
str r2, [r1], #4 /* Save the floating point control and status register */
#endif
bx lr
.size up_savefpu, .-up_savefpu
/************************************************************************************
* Name: up_restorefpu
*
* Description:
* Given the pointer to a register save area (in R0), restore the state of the
* floating point registers.
*
* C Function Prototype:
* void up_restorefpu(const uint32_t *regs);
*
* Input Parameters:
* regs - A pointer to the register save area containing the floating point
* registers.
*
* Returned Value:
* This function does not return anything explicitly. However, it is called from
* interrupt level assembly logic that assumes that r0 is preserved.
*
************************************************************************************/
.thumb_func
.type up_restorefpu, function
up_restorefpu:
add r1, r0, #(4*REG_S0) /* R1=Address of FP register storage */
/* Some older GNU assemblers don't support all the newer UAL mnemonics. */
#if 1 /* Use UAL mnemonics */
/* Load all floating point registers. Registers are loaded in numeric order,
* s0, s1, ... in increasing address order.
*/
vldmia r1!, {s0-s31} /* Restore the full FP context */
/* Load the floating point control and status register. At the end of the
* vstmia, r1 will point to the FPCSR storage location.
*/
ldr r2, [r1], #4 /* Fetch the floating point control and status register */
vmsr fpscr, r2 /* Restore the FPCSR */
#else
/* Load all floating point registers Registers are loaded in numeric order,
* s0, s1, ... in increasing address order.
*/
#if 1 /* Use load multiple */
fldmias r1!, {s0-s31} /* Restore the full FP context */
#else
ldr r2, [r1], #4 /* Fetch S0 and S1 values */
ldr r3, [r1], #4
vmov d0, r2, r3 /* Save as d0 */
ldr r2, [r1], #4 /* Fetch S2 and S3 values */
ldr r3, [r1], #4
vmov d1, r2, r3 /* Save as d1 */
ldr r2, [r1], #4 /* Fetch S4 and S5 values */
ldr r3, [r1], #4
vmov d2, r2, r3 /* Save as d2 */
ldr r2, [r1], #4 /* Fetch S6 and S7 values */
ldr r3, [r1], #4
vmov d3, r2, r3 /* Save as d3 */
ldr r2, [r1], #4 /* Fetch S8 and S9 values */
ldr r3, [r1], #4
vmov d4, r2, r3 /* Save as d4 */
ldr r2, [r1], #4 /* Fetch S10 and S11 values */
ldr r3, [r1], #4
vmov d5, r2, r3 /* Save as d5 */
ldr r2, [r1], #4 /* Fetch S12 and S13 values */
ldr r3, [r1], #4
vmov d6, r2, r3 /* Save as d6 */
ldr r2, [r1], #4 /* Fetch S14 and S15 values */
ldr r3, [r1], #4
vmov d7, r2, r3 /* Save as d7 */
ldr r2, [r1], #4 /* Fetch S16 and S17 values */
ldr r3, [r1], #4
vmov d8, r2, r3 /* Save as d8 */
ldr r2, [r1], #4 /* Fetch S18 and S19 values */
ldr r3, [r1], #4
vmov d9, r2, r3 /* Save as d9 */
ldr r2, [r1], #4 /* Fetch S20 and S21 values */
ldr r3, [r1], #4
vmov d10, r2, r3 /* Save as d10 */
ldr r2, [r1], #4 /* Fetch S22 and S23 values */
ldr r3, [r1], #4
vmov d11, r2, r3 /* Save as d11 */
ldr r2, [r1], #4 /* Fetch S24 and S25 values */
ldr r3, [r1], #4
vmov d12, r2, r3 /* Save as d12 */
ldr r2, [r1], #4 /* Fetch S26 and S27 values */
ldr r3, [r1], #4
vmov d13, r2, r3 /* Save as d13 */
ldr r2, [r1], #4 /* Fetch S28 and S29 values */
ldr r3, [r1], #4
vmov d14, r2, r3 /* Save as d14 */
ldr r2, [r1], #4 /* Fetch S30 and S31 values */
ldr r3, [r1], #4
vmov d15, r2, r3 /* Save as d15 */
#endif
/* Load the floating point control and status register. r1 points t
* the address of the FPCSR register.
*/
ldr r2, [r1], #4 /* Fetch the floating point control and status register */
fmxr fpscr, r2 /* Restore the FPCSR */
#endif
bx lr
.size up_restorefpu, .-up_restorefpu
#endif /* CONFIG_ARCH_FPU */
.end
