1.. SPDX-License-Identifier: GPL-2.0+
2
3UEFI subsystem
4==============
5
6Lauching UEFI images
7--------------------
8
9Bootefi command
10~~~~~~~~~~~~~~~
11
12The bootefi command is used to start UEFI applications or to install UEFI
13drivers. It takes two parameters
14
15    bootefi <image address> [fdt address]
16
17* image address - the memory address of the UEFI binary
18* fdt address - the memory address of the flattened device tree
19
20The environment variable 'bootargs' is passed as load options in the UEFI system
21table. The Linux kernel EFI stub uses the load options as command line
22arguments.
23
24.. kernel-doc:: cmd/bootefi.c
25   :internal:
26
27Boot manager
28~~~~~~~~~~~~
29
30The UEFI specification foresees to define boot entries and boot sequence via UEFI
31variables. Booting according to these variables is possible via
32
33    bootefi bootmgr [fdt address]
34
35* fdt address - the memory address of the flattened device tree
36
37The relevant variables are:
38
39* Boot0000-BootFFFF define boot entries
40* BootNext specifies next boot option to be booted
41* BootOrder specifies in which sequence the boot options shall be tried if
42  BootNext is not defined or booting via BootNext fails
43
44.. kernel-doc:: lib/efi_loader/efi_bootmgr.c
45   :internal:
46
47Efidebug command
48~~~~~~~~~~~~~~~~
49
50The efidebug command is used to set and display boot options as well as to
51display information about internal data of the UEFI subsystem (devices,
52drivers, handles, loaded images, and the memory map).
53
54.. kernel-doc:: cmd/efidebug.c
55   :internal:
56
57Initialization of the UEFI sub-system
58-------------------------------------
59
60.. kernel-doc:: lib/efi_loader/efi_setup.c
61   :internal:
62
63Boot services
64-------------
65
66.. kernel-doc:: lib/efi_loader/efi_boottime.c
67   :internal:
68
69Image relocation
70~~~~~~~~~~~~~~~~
71
72.. kernel-doc:: lib/efi_loader/efi_image_loader.c
73   :internal:
74
75Memory services
76~~~~~~~~~~~~~~~
77
78.. kernel-doc:: lib/efi_loader/efi_memory.c
79   :internal:
80
81SetWatchdogTimer service
82~~~~~~~~~~~~~~~~~~~~~~~~
83
84.. kernel-doc:: lib/efi_loader/efi_watchdog.c
85   :internal:
86
87Runtime services
88----------------
89
90.. kernel-doc:: lib/efi_loader/efi_runtime.c
91   :internal:
92
93Variable services
94~~~~~~~~~~~~~~~~~
95
96.. kernel-doc:: lib/efi_loader/efi_variable.c
97   :internal:
98
99UEFI drivers
100------------
101
102UEFI driver uclass
103~~~~~~~~~~~~~~~~~~
104.. kernel-doc:: lib/efi_driver/efi_uclass.c
105   :internal:
106
107Block device driver
108~~~~~~~~~~~~~~~~~~~
109
110.. kernel-doc:: lib/efi_driver/efi_block_device.c
111   :internal:
112
113Protocols
114---------
115
116Block IO protocol
117~~~~~~~~~~~~~~~~~
118
119.. kernel-doc:: lib/efi_loader/efi_disk.c
120   :internal:
121
122File protocol
123~~~~~~~~~~~~~
124
125.. kernel-doc:: lib/efi_loader/efi_file.c
126   :internal:
127
128Graphical output protocol
129~~~~~~~~~~~~~~~~~~~~~~~~~
130
131.. kernel-doc:: lib/efi_loader/efi_gop.c
132   :internal:
133
134Load file 2 protocol
135~~~~~~~~~~~~~~~~~~~~
136
137The load file 2 protocol can be used by the Linux kernel to load the initial
138RAM disk. U-Boot can be configured to provide an implementation.
139
140.. kernel-doc:: lib/efi_loader/efi_load_initrd.c
141   :internal:
142
143Network protocols
144~~~~~~~~~~~~~~~~~
145
146.. kernel-doc:: lib/efi_loader/efi_net.c
147   :internal:
148
149Random number generator protocol
150~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
151
152.. kernel-doc:: lib/efi_loader/efi_rng.c
153   :internal:
154
155Text IO protocols
156~~~~~~~~~~~~~~~~~
157
158.. kernel-doc:: lib/efi_loader/efi_console.c
159   :internal:
160
161Unicode Collation protocol
162~~~~~~~~~~~~~~~~~~~~~~~~~~
163
164.. kernel-doc:: lib/efi_loader/efi_unicode_collation.c
165   :internal:
166
167Unit testing
168------------
169
170The following library functions are provided to support writing UEFI unit tests.
171The should not be used elsewhere.
172
173.. kernel-doc:: include/efi_selftest.h
174   :internal:
175