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
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Bootmethod for distro boot via EFI
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#include <efi_loader.h>
#include <env.h>
#include <errno.h>
#include <log.h>
#include <string.h>
#include <vsprintf.h>
/**
* distro_efi_get_fdt_name() - get the filename for reading the .dtb file
*
* @fname: buffer for filename
* @size: buffer size
* @seq: sequence number, to cycle through options (0=first)
*
* Returns:
* 0 on success,
* -ENOENT if the "fdtfile" env var does not exist,
* -EINVAL if there are no more options,
* -EALREADY if the control FDT should be used
*/
int efi_get_distro_fdt_name(char *fname, int size, int seq)
{
const char *fdt_fname;
const char *prefix;
/* select the prefix */
switch (seq) {
case 0:
/* this is the default */
prefix = "/dtb";
break;
case 1:
prefix = "";
break;
case 2:
prefix = "/dtb/current";
break;
default:
return log_msg_ret("pref", -EINVAL);
}
fdt_fname = env_get("fdtfile");
if (fdt_fname) {
snprintf(fname, size, "%s/%s", prefix, fdt_fname);
log_debug("Using device tree: %s\n", fname);
} else if (IS_ENABLED(CONFIG_OF_HAS_PRIOR_STAGE)) {
strcpy(fname, "<prior>");
return log_msg_ret("pref", -EALREADY);
/* Use this fallback only for 32-bit ARM */
} else if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_ARM64)) {
const char *soc = env_get("soc");
const char *board = env_get("board");
const char *boardver = env_get("boardver");
/* cf the code in label_boot() which seems very complex */
snprintf(fname, size, "%s/%s%s%s%s.dtb", prefix,
soc ? soc : "", soc ? "-" : "", board ? board : "",
boardver ? boardver : "");
log_debug("Using default device tree: %s\n", fname);
} else {
return log_msg_ret("env", -ENOENT);
}
return 0;
}
/**
* efi_load_distro_fdt() - load distro device-tree
*
* @fdt: on return device-tree, must be freed via efi_free_pages()
* @fdt_size: buffer size
*/
void efi_load_distro_fdt(void **fdt, efi_uintn_t *fdt_size)
{
struct efi_device_path *rem, *dp;
efi_status_t ret;
efi_handle_t device;
*fdt = NULL;
dp = efi_get_dp_from_boot(NULL);
if (!dp)
return;
device = efi_dp_find_obj(dp, NULL, &rem);
ret = efi_search_protocol(device, &efi_simple_file_system_protocol_guid,
NULL);
if (ret != EFI_SUCCESS)
goto err;
memcpy(rem, &END, sizeof(END));
/* try the various available names */
for (int seq = 0; ; ++seq) {
struct efi_device_path *file;
char buf[255];
if (efi_get_distro_fdt_name(buf, sizeof(buf), seq))
break;
file = efi_dp_from_file(dp, buf);
if (!file)
break;
ret = efi_load_image_from_path(true, file, fdt, fdt_size);
efi_free_pool(file);
if (ret == EFI_SUCCESS)
break;
}
err:
efi_free_pool(dp);
}
|
