xref: /qemu/tests/migration/aarch64/a-b-kernel.S (revision b2a3cbb8)
1#
2# Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
3#
4# Author:
5#   Wei Huang <wei@redhat.com>
6#
7# This work is licensed under the terms of the GNU GPL, version 2 or later.
8# See the COPYING file in the top-level directory.
9#
10# Note: Please make sure the compiler compiles the assembly code below with
11# pc-relative address. Also the branch instructions should use relative
12# addresses only.
13
14#include "../migration-test.h"
15
16.section .text
17
18        .globl  _start
19
20_start:
21        /* disable MMU to use phys mem address */
22        mrs     x0, sctlr_el1
23        bic     x0, x0, #(1<<0)
24        msr     sctlr_el1, x0
25        isb
26
27        /* traverse test memory region */
28        mov     x0, #ARM_TEST_MEM_START
29        mov     x1, #ARM_TEST_MEM_END
30
31        /* output char 'A' to PL011 */
32        mov     w3, 'A'
33        mov     x2, #ARM_MACH_VIRT_UART
34        strb    w3, [x2]
35
36        /* clean up memory */
37        mov     w3, #0
38        mov     x4, x0
39clean:
40        strb    w3, [x4]
41        add     x4, x4, #TEST_MEM_PAGE_SIZE
42        cmp     x4, x1
43        ble     clean
44
45        /* w5 keeps a counter so we can limit the output speed */
46        mov     w5, #0
47
48        /* main body */
49mainloop:
50        mov     x4, x0
51
52innerloop:
53        /* increment the first byte of each page by 1 */
54        ldrb    w3, [x4]
55        add     w3, w3, #1
56        strb    w3, [x4]
57
58        /* make sure QEMU user space can see consistent data as MMU is off */
59        dc      civac, x4
60
61        add     x4, x4, #TEST_MEM_PAGE_SIZE
62        cmp     x4, x1
63        blt     innerloop
64
65        add     w5, w5, #1
66        and     w5, w5, #0x1f
67        cmp     w5, #0
68        bne     mainloop
69
70        /* output char 'B' to PL011 */
71        mov     w3, 'B'
72        strb    w3, [x2]
73
74        b       mainloop
75