os_cpu_fpu_a.asm

Micrium-uCOS-II-V283.ZIP源码

;
;********************************************************************************************************
;                                               uC/OS-II
;                                         The Real-Time Kernel
;
;
;                             (c) Copyright 1992-2007, Micrium, Weston, FL
;                                          All Rights Reserved
;
;                                           Generic ARM Port
;                                              VFP SUPPORT
;
; File      : OS_CPU_FPU_A.ASM
; Version   : V1.82
; By        : Eric Shufro
;
; For       : ARM7 or ARM9
; Mode      : ARM or Thumb
; Toolchain : IAR's EWARM V4.11a and higher
;********************************************************************************************************
;

;********************************************************************************************************
;                                           PUBLIC FUNCTIONS
;********************************************************************************************************

    PUBLIC  OS_CPU_FP_Restore
    PUBLIC  OS_CPU_FP_Save

;********************************************************************************************************
;                                      CODE GENERATION DIRECTIVES
;********************************************************************************************************

    RSEG CODE:CODE:NOROOT(2)
    CODE32

;*********************************************************************************************************
;                                           RESTORE VFP REGISTERS
;                                       void OS_CPU_FP_Restore(void *pblk)
;
; Description : This function is called to restore the contents of the VFP registers during a context
;               switch.  It is assumed that a pointer to a storage area for the VFP registers is placed
;               in the task's TCB (i.e. .OSTCBExtPtr).

; Arguments   : pblk    is passed to this function in R0 when called.
;
; Notes       : Floating point math should NEVER be performed within an ISR as this will corrupt
;               the state of the VFP registers for the last VFP task that ran. Instead, all floating
;               point math should be performed within floating point enabled tasks ONLY.
;*********************************************************************************************************

OS_CPU_FP_Restore
        FLDMIAS R0!, {S0-S31}           ; Restore the VFP registers from pblk
        BX      LR                      ; Return to calling function

;*********************************************************************************************************
;                                           SAVE VFP REGISTERS
;                                        void OS_CPU_FP_Save(void *pblk)
;
; Description : This function is called to save the contents of the VFP registers during a context
;               switch.  It is assumed that a pointer to a storage area for the VFP registers is placed
;               in the task's TCB (i.e. .OSTCBExtPtr).
;
; Arguments   : pblk    is passed to this function in R0 when called.
;
; Notes       : Floating point math should NEVER be performed within an ISR as this will corrupt
;               the state of the VFP registers for the last VFP task that ran. Instead, all floating
;               point math should be performed within floating point enabled tasks ONLY.
;*********************************************************************************************************

OS_CPU_FP_Save
        FSTMIAS R0!, {S0-S31}           ; Save the VFP registers in pblk
        BX      LR                      ; Return to calling function


        END