xref: /openbmc/qemu/include/gdbstub/helpers.h (revision 2e1cacfb)
1 /*
2  * gdbstub helpers
3  *
4  * These are all used by the various frontends and have to be host
5  * aware to ensure things are store in target order.
6  *
7  * Copyright (c) 2022 Linaro Ltd
8  *
9  * SPDX-License-Identifier: GPL-2.0-or-later
10  */
11 
12 #ifndef _GDBSTUB_HELPERS_H_
13 #define _GDBSTUB_HELPERS_H_
14 
15 #ifndef COMPILING_PER_TARGET
16 #error "gdbstub helpers should only be included by target specific code"
17 #endif
18 
19 #include "exec/tswap.h"
20 #include "cpu-param.h"
21 
22 /*
23  * The GDB remote protocol transfers values in target byte order. As
24  * the gdbstub may be batching up several register values we always
25  * append to the array.
26  */
27 
28 static inline int gdb_get_reg8(GByteArray *buf, uint8_t val)
29 {
30     g_byte_array_append(buf, &val, 1);
31     return 1;
32 }
33 
34 static inline int gdb_get_reg16(GByteArray *buf, uint16_t val)
35 {
36     uint16_t to_word = tswap16(val);
37     g_byte_array_append(buf, (uint8_t *) &to_word, 2);
38     return 2;
39 }
40 
41 static inline int gdb_get_reg32(GByteArray *buf, uint32_t val)
42 {
43     uint32_t to_long = tswap32(val);
44     g_byte_array_append(buf, (uint8_t *) &to_long, 4);
45     return 4;
46 }
47 
48 static inline int gdb_get_reg64(GByteArray *buf, uint64_t val)
49 {
50     uint64_t to_quad = tswap64(val);
51     g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
52     return 8;
53 }
54 
55 static inline int gdb_get_reg128(GByteArray *buf, uint64_t val_hi,
56                                  uint64_t val_lo)
57 {
58     uint64_t to_quad;
59 #if TARGET_BIG_ENDIAN
60     to_quad = tswap64(val_hi);
61     g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
62     to_quad = tswap64(val_lo);
63     g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
64 #else
65     to_quad = tswap64(val_lo);
66     g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
67     to_quad = tswap64(val_hi);
68     g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
69 #endif
70     return 16;
71 }
72 
73 static inline int gdb_get_zeroes(GByteArray *array, size_t len)
74 {
75     guint oldlen = array->len;
76     g_byte_array_set_size(array, oldlen + len);
77     memset(array->data + oldlen, 0, len);
78 
79     return len;
80 }
81 
82 /**
83  * gdb_get_reg_ptr: get pointer to start of last element
84  * @len: length of element
85  *
86  * This is a helper function to extract the pointer to the last
87  * element for additional processing. Some front-ends do additional
88  * dynamic swapping of the elements based on CPU state.
89  */
90 static inline uint8_t *gdb_get_reg_ptr(GByteArray *buf, int len)
91 {
92     return buf->data + buf->len - len;
93 }
94 
95 #if TARGET_LONG_BITS == 64
96 #define gdb_get_regl(buf, val) gdb_get_reg64(buf, val)
97 #define ldtul_p(addr) ldq_p(addr)
98 #define ldtul_le_p(addr) ldq_le_p(addr)
99 #define ldtul_be_p(addr) ldq_be_p(addr)
100 #else
101 #define gdb_get_regl(buf, val) gdb_get_reg32(buf, val)
102 #define ldtul_p(addr) ldl_p(addr)
103 #define ldtul_le_p(addr) ldl_le_p(addr)
104 #define ldtul_be_p(addr) ldl_be_p(addr)
105 #endif
106 
107 #endif /* _GDBSTUB_HELPERS_H_ */
108