1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
;/*
; * Copyright (c) 2006-2018, RT-Thread Development Team
; *
; * SPDX-License-Identifier: Apache-2.0
; *
; * Change Logs:
; * Date Author Notes
; * 2018-10-30 heyuanjie first version
; */
AREA |.text|, CODE, READONLY, ALIGN=2
THUMB
REQUIRE8
PRESERVE8
;/*
; * void* lwp_get_sys_api(rt_uint32_t number);
; */
IMPORT lwp_get_sys_api
IMPORT lwp_get_kernel_sp
IMPORT lwp_set_kernel_sp
;/*
; * void lwp_user_entry(args, text, data);
; */
lwp_user_entry PROC
EXPORT lwp_user_entry
PUSH {R0-R3} ; push text&data addr.
MOV R0, SP ; v1 = SP
BL lwp_set_kernel_sp ; lwp_set_kernel_sp(v1)
; set CPU to user-thread mode.
MRS R2, CONTROL
ORR R2, R2, #0x03 ; use PSP, user-thread mode.
MSR CONTROL, R2
POP {R0-R3} ; pop app address to R1.
; set data address.
MOV R9, R2
; run app, only Thumb-mode.
ORR R1, R1, #0x01
BX R1
; never reach here!
ENDP
;/*
; * void SVC_Handler(void);
; */
SVC_Handler PROC
EXPORT SVC_Handler
PUSH {LR}
; get user SP.
TST LR, #0x4
ITE EQ
MRSEQ R1, MSP
MRSNE R1, PSP
PUSH {R1} ; push app SP.
; get SVC number.
mov R0, R7
; get kernel system API
BL lwp_get_sys_api
PUSH {R0} ; push api
; get kernel SP to R0.
BL lwp_get_kernel_sp
POP {R2} ; pop api to R2.
POP {R1} ; pop app SP to R1.
stmfd r0!, {r1} ; save app SP to kernel SP
;push app parm5~6 to kernel SP
STMFD R0!, {R4 - R5}
; copy R1(app SP) to R0(kernel SP).
push {r8-r11}
LDMFD R1, {R4 - R11} ; pop exception_stack_frame to r4 - r11 register
STMFD R0!, {R4 - R11} ; push exception_stack_frame to server SP.
pop {r8-r11}
LDR R3, =svc_exit
STR R3, [R0, #20] ; update LR
STR R2, [R0, #24] ; update api to PC
MSR PSP, R0 ; update SP, API is executed with kernel SP
; set to thread-privilege mode.
MRS R3, CONTROL
BIC R3, R3, #0x01
ORR R3, R3, #0x02
MSR CONTROL, R3
POP {LR} ; 0xFFFFFFED
ORR LR, LR, #0x10
BX LR
ENDP
;/*
; * void svc_exit(void);
; */
svc_exit PROC
EXPORT svc_exit
; get user SP.
PUSH {R0} ; push result to SP.
BL lwp_get_kernel_sp
ldr r3, [r0, #-4]
pop {r0}
ldr lr, [r3, #20]
ldr r1, [r3, #24] ; load pc
add r3, #32 ; exception_stack_frame size
MSR PSP, R3 ; restore app stack pointer
; restore to PSP & thread-unprivilege mode.
MRS R2, CONTROL
ORR R2, R2, #0x03
MSR CONTROL, R2
; return to lwp.
ORR R1, R1, #0x01 ; only Thumb-mode.
BX R1 ; return to user app.
ENDP
ALIGN
END
|
