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
|
.global data_abort
data_abort:
mrc p15, 0, r2, c6, c0, 0
mrc p15, 0, r3, c5, c0, 0
mov pc, r4
.global reset
reset:
# Copy code to page 3
ldr r0, =.virtual_start
ldr r1, =0x3000
ldr r2, =256
.copy_virtual:
ldr r3, [r0], #4
str r3, [r1], #4
subs r2, r2, #4
bne .copy_virtual
# Translation tables
mov r0, #0x4000
ldr r1, =0x00005001
str r1, [r0]
mov r1, #0x5000
ldr r2, =0x00000002
str r2, [r1], #4
str r2, [r1], #4
str r2, [r1], #4
str r2, [r1], #4
ldr r2, =0x00003002
str r2, [r1], #4
# Set translation base and enable MMU
mov r1, #(1 << 0)
mcr p15, 0, r0, c2, c0, 0
mcr p15, 0, r1, c1, c0, 0
# Self-relocate to 0x2000 (mirror of 0x0000)
ldr r1, =#(0x2000 - 4)
add pc, pc, r1
# Jump to .virtual_start (phys: 0x3000, virt: 0x4000)
ldr r0, =0x01234567
ldr pc, =0x4000
b .
.virtual_start:
ldr r1, =0x89abcdef
and r6, r1, #~0xf
mov r4, lr
mov r5, lr
# This triggers a page fault
ldr r4, [r6]
|
