rt-thread/libcpu/ti-dsp/c6x/stack.asm

;
; Copyright (c) 2021, Shenzhen Academy of Aerospace Technology
;
; SPDX-License-Identifier: Apache-2.0
;
; Change Logs:
; Date           Author       Notes
; 2021-11-16     Dystopia     the first version
;

;-----------------------------------------------------------
; 			build thread stack for C6000 DSP
;-----------------------------------------------------------

;-----------------------------------------------------------
;					macro definition
;-----------------------------------------------------------
ADDRESS_MSK .set    0xFFFFFFF0

;
;-----------------------------------------------------------
;

    .sect   ".text"
;
;-----------------------------------------------------------
;

;
; rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter, rt_uint8_t *stack_addr, void *texit)
; tentry  --> A4
; parameter --> B4
; stack_addr --> A6
; texit  --> B6
;{
    .global rt_hw_stack_init
rt_hw_stack_init:
	SUB		A6,1,B1                 ;
    MVKL	.S1	ADDRESS_MSK,A1      ;
    MVKH	.S1	ADDRESS_MSK,A1      ; Build address mask
	MVC	.S2	CSR,B0                  ;
	AND		-2,B0,B0                ; Clear GIE bit
	OR		2,B0,B0                 ; Set PGIE bit for interrupt return
	AND		A1,B1,B1                ; Ensure alignment
;
; Actually build the stack frame.
;
	MV	.S1	B1,A3
	MV	.S1	B14,A2
	STDW	.D2T1	A3:A2,*--B1[1]  ; Initial B15:B14
	SUBAW	.D2	B1,2,B1
	ZERO	A2
	ZERO	A3                      ; Clear value
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A15:A14
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A13:A12
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A11:A10
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A9:A8
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A7:A6
	MV	.S1	B4,A2
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A5:A4
	ZERO	A2
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A3:A2
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A1:A0

	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A31:A30
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A29:A28
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A27:A26
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A25:A24
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A23:A22
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A21:A20
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A19:A18
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial A17:A16

	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B13:B12
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B11:B10
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B9:B8
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B7:B6
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B5:B4
	MV	.S1	B6,A3
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B3:B2
	ZERO	A3
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B1:B0

	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B31:B30
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B29:B28
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B27:B26
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B25:B24
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B23:B22
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B21:B20
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B19:B18
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial B17:B16

	MV	.S1	A4,A3
	MV	.S1	B0,A2
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial PC:CSR

	ZERO	A2
	ZERO	A3
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial ILC:RILC
	B	B3
	MVKL	.S2	0x3,B0
	MV	.S1	B0,A3
	MVKL	.S1	1,A2
	STDW	.D2T1	A3:A2,*B1--[1]  ; Initial TSR:stack type
	MV	.S1	B1,A4                   ; Save to TCB
;}
	.end