context_frame.h

Thread context frame stored on stack.

pad_OFFSET
1
0
pc_OFFSET
1
8
s0_OFFSET
1
12
s1_OFFSET
1
16
s2_OFFSET
1
20
s3_OFFSET
1
24
s4_OFFSET
1
28
s5_OFFSET
1
32
s6_OFFSET
1
36
s7_OFFSET
1
40
s8_OFFSET
1
44
s9_OFFSET
1
48
s10_OFFSET
1
52
s11_OFFSET
1
56
ra_OFFSET
1
60
tp_OFFSET
1
64
t0_OFFSET
1
68
t1_OFFSET
1
72
t2_OFFSET
1
76
t3_OFFSET
1
80
t4_OFFSET
1
84
t5_OFFSET
1
88
t6_OFFSET
1
92
a0_OFFSET
1
96
a1_OFFSET
1
100
a2_OFFSET
1
104
a3_OFFSET
1
108
a4_OFFSET
1
112
a5_OFFSET
1
116
a6_OFFSET
1
120
a7_OFFSET
1
124
CONTEXT_FRAME_SIZE

Size of context switch frame. 

1
(a7_OFFSET + 4)
SP_OFFSET_IN_THREAD

Offset of stack pointer in struct _thread. 

1
0
struct context_switch_frame

Stores the registers and PC for a context switch.

This also defines context_switch_frame offsets for assembly language. The structure is sized to maintain 16 byte stack alignment per the ABI. https://github.com/riscv/riscv-elf-psabi-doc

uint32_t pad()

padding to maintain 16 byte alignment

uint32_t pc

program counter

uint32_t s0

s0 register

uint32_t s1

s1 register

uint32_t s2

s2 register

uint32_t s3

s3 register

uint32_t s4

s4 register

uint32_t s5

s5 register

uint32_t s6

s6 register

uint32_t s7

s7 register

uint32_t s8

s8 register

uint32_t s9

s9 register

uint32_t s10

s10 register

uint32_t s11

s11 register

uint32_t ra

ra register

uint32_t tp

tp register

uint32_t t0

t0 register

uint32_t t1

t1 register

uint32_t t2

t2 register

uint32_t t3

t3 register

uint32_t t4

t4 register

uint32_t t5

t5 register

uint32_t t6

t6 register

uint32_t a0

a0 register

uint32_t a1

a1 register

uint32_t a2

a2 register

uint32_t a3

a3 register

uint32_t a4

a4 register

uint32_t a5

a5 register

uint32_t a6

a6 register

uint32_t a7

a7 register