rt-thread/libcpu/ti-dsp/c28x/context.s

294 lines
6.3 KiB
ArmAsm

;
; Copyright (c) 2006-2018, RT-Thread Development Team
;
; SPDX-License-Identifier: Apache-2.0
;
; Change Logs:
; Date Author Notes
; 2018-09-01 xuzhuoyi the first version.
; 2019-06-17 zhaoxiaowei fix bugs of old c28x interrupt api.
; 2019-07-03 zhaoxiaowei add _rt_hw_calc_csb function to support __rt_ffs.
;
.ref _rt_interrupt_to_thread
.ref _rt_interrupt_from_thread
.ref _rt_thread_switch_interrupt_flag
.def _RTOSINT_Handler
.def _rt_hw_get_st0
.def _rt_hw_get_st1
.def _rt_hw_calc_csb
.def _rt_hw_context_switch_interrupt
.def _rt_hw_context_switch
.def _rt_hw_context_switch_to
.def _rt_hw_interrupt_thread_switch
.def _rt_hw_interrupt_disable
.def _rt_hw_interrupt_enable
RT_CTX_SAVE .macro
PUSH AR1H:AR0H
PUSH XAR2
PUSH XAR3
PUSH XAR4
PUSH XAR5
PUSH XAR6
PUSH XAR7
PUSH XT
PUSH RPC
.endm
RT_CTX_RESTORE .macro
POP RPC
POP XT
POP XAR7
POP XAR6
POP XAR5
POP XAR4
POP XAR3
POP XAR2
MOVZ AR0 , @SP
SUBB XAR0, #6
MOVL ACC , *XAR0
AND ACC, #0xFFFF << 16
MOV AL, IER
MOVL *XAR0, ACC
POP AR1H:AR0H
.endm
.text
.newblock
;
; rt_base_t rt_hw_interrupt_disable();
;
.asmfunc
_rt_hw_interrupt_disable:
PUSH ST1
SETC INTM,DBGM
MOV AL, *--SP
LRETR
.endasmfunc
;
; void rt_hw_interrupt_enable(rt_base_t level);
;
.asmfunc
_rt_hw_interrupt_enable:
MOV *SP++, AL
POP ST1
LRETR
.endasmfunc
;
; void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
; r0 --> from
; r4 --> to
.asmfunc
_rt_hw_context_switch_interrupt:
MOVL XAR0, #0
MOV AR0, AL
MOVL XAR4, *-SP[4]
; set rt_thread_switch_interrupt_flag to 1
MOVL XAR5, #_rt_thread_switch_interrupt_flag
MOVL XAR6, *XAR5
MOVL ACC, XAR6
CMPB AL, #1
B _reswitch, EQ
MOVL XAR6, #1
MOVL *XAR5, XAR6
MOVL XAR5, #_rt_interrupt_from_thread ; set rt_interrupt_from_thread
MOVL *XAR5, XAR0
_reswitch:
MOVL XAR5, #_rt_interrupt_to_thread ; set rt_interrupt_to_thread
MOVL *XAR5, XAR4
LRETR
.endasmfunc
;
; void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
; r0 --> from
; r4 --> to
.asmfunc
_rt_hw_context_switch:
MOVL XAR0, #0
MOV AR0, AL
MOVL XAR4, *-SP[4]
; set rt_thread_switch_interrupt_flag to 1
MOVL XAR5, #_rt_thread_switch_interrupt_flag
MOVL XAR6, *XAR5
MOVL ACC, XAR6
CMPB AL, #1
B _reswitch2, EQ
MOVL XAR6, #1
MOVL *XAR5, XAR6
MOVL XAR5, #_rt_interrupt_from_thread ; set rt_interrupt_from_thread
MOVL *XAR5, XAR0
_reswitch2:
MOVL XAR5, #_rt_interrupt_to_thread ; set rt_interrupt_to_thread
MOVL *XAR5, XAR4
TRAP #16
LRETR
.endasmfunc
.asmfunc
_RTOSINT_Handler:
; disable interrupt to protect context switch
DINT
; get rt_thread_switch_interrupt_flag
MOV AR0, #_rt_thread_switch_interrupt_flag
MOV AL, *AR0
MOV AR1, AL
CMP AR1, #0
B rtosint_exit, EQ ; pendsv already handled
; clear rt_thread_switch_interrupt_flag to 0
MOV AR1, #0x00
MOV *AR0, AR1
MOV AR0, #_rt_interrupt_from_thread
MOV AL, *AR0
MOV AR1, AL
CMP AR1, #0
B switch_to_thread, EQ ; skip register save at the first time
;#if defined (__VFP_FP__) && !defined(__SOFTFP__)
; TST lr, #0x10 ; if(!EXC_RETURN[4])
; VSTMDBEQ r1!, {d8 - d15} ; push FPU register s16~s31
;#endif
RT_CTX_SAVE ; push r4 - r11 register
;#if defined (__VFP_FP__) && !defined(__SOFTFP__)
; MOV r4, #0x00 ; flag = 0
; TST lr, #0x10 ; if(!EXC_RETURN[4])
; MOVEQ r4, #0x01 ; flag = 1
; STMFD r1!, {r4} ; push flag
;#endif
MOV AL, *AR0
MOV AR0, AL
MOVZ AR1, @SP ; get from thread stack pointer
MOV *AR0, AR1 ; update from thread stack pointer
switch_to_thread:
MOV AR1, #_rt_interrupt_to_thread
MOV AL, *AR1
MOV AR1, AL
MOV AL, *AR1
MOV AR1, AL ; load thread stack pointer
;#if defined (__VFP_FP__) && !defined(__SOFTFP__)
; LDMFD r1!, {r3} ; pop flag
;#endif
MOV @SP, AR1
RT_CTX_RESTORE ; pop r4 - r11 register
rtosint_exit:
; restore interrupt
EINT
IRET
.endasmfunc
.asmfunc
_rt_hw_get_st0:
PUSH ST0
POP AL
LRETR
.endasmfunc
.asmfunc
_rt_hw_get_st1:
PUSH ST1
POP AL
LRETR
.endasmfunc
; C28x do not have a build-in "__ffs" func in its C compiler.
; We can use the "Count Sign Bits" (CSB) instruction to make one.
; CSB will return the number of 0's minus 1 above the highest set bit.
; The count is placed in T. For example:
; ACC T maxbit
; 0x00000001 30 0
; 0x00000010 26 4
; 0x000001FF 22 8
; 0x000001F0 22 8
.asmfunc
_rt_hw_calc_csb:
MOV AH, #0
CSB ACC ; T = no. of sign bits - 1
MOVU ACC, T ; ACC = no. of sign bits - 1
SUBB ACC, #30 ; ACC = ACC - 30
ABS ACC ; ACC = |ACC|
lretr
.endasmfunc
;
; * void rt_hw_context_switch_to(rt_uint32 to);
; * r0 --> to
.asmfunc
_rt_hw_context_switch_to:
MOV AR1, #_rt_interrupt_to_thread
MOV *AR1, AL
;#if defined (__VFP_FP__) && !defined(__SOFTFP__)
; CLEAR CONTROL.FPCA
; MRS r2, CONTROL ; read
; BIC r2, #0x04 ; modify
; MSR CONTROL, r2 ; write-back
;#endif
; set from thread to 0
MOV AR1, #_rt_interrupt_from_thread
MOV AR0, #0x0
MOV *AR1, AR0
; set interrupt flag to 1
MOV AR1, #_rt_thread_switch_interrupt_flag
MOV AR0, #1
MOV *AR1, AR0
TRAP #16
; never reach here!
.endasmfunc
; compatible with old version
.asmfunc
_rt_hw_interrupt_thread_switch:
LRETR
NOP
.endasmfunc
.end