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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 598a06dcb47db8101a19d26c0d65572fbe8e71f6 / . / doc / api / efi.rst
blob: cb2a1c897e69282075352b02c33c735f9b2b8c26 [file] [log] [blame]
Heinrich Schuchardt04459782018-07-29 13:45:47 +0200[diff] [blame]1.. SPDX-License-Identifier: GPL-2.0+
2
Heinrich Schuchardtc0b352e2019-07-14 14:05:37 +0200[diff] [blame]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:
Heinrich Schuchardt04459782018-07-29 13:45:47 +0200[diff] [blame]62
63Boot services
64-------------
65
66.. kernel-doc:: lib/efi_loader/efi_boottime.c
67 :internal:
68
Heinrich Schuchardt1db561e2019-02-16 15:22:13 +0100[diff] [blame]69Image relocation
70~~~~~~~~~~~~~~~~
71
72.. kernel-doc:: lib/efi_loader/efi_image_loader.c
73 :internal:
74
Heinrich Schuchardtc0b352e2019-07-14 14:05:37 +0200[diff] [blame]75Memory services
76~~~~~~~~~~~~~~~
77
78.. kernel-doc:: lib/efi_loader/efi_memory.c
79 :internal:
80
Heinrich Schuchardt540faca2020-04-10 17:51:56 +0200[diff] [blame]81SetWatchdogTimer service
82~~~~~~~~~~~~~~~~~~~~~~~~
83
84.. kernel-doc:: lib/efi_loader/efi_watchdog.c
85 :internal:
86
Heinrich Schuchardt04459782018-07-29 13:45:47 +0200[diff] [blame]87Runtime services
88----------------
89
90.. kernel-doc:: lib/efi_loader/efi_runtime.c
91 :internal:
Heinrich Schuchardtc0b352e2019-07-14 14:05:37 +0200[diff] [blame]92
93Variable services
94~~~~~~~~~~~~~~~~~
95
Heinrich Schuchardtf2d2b3a2020-06-22 18:10:27 +0200[diff] [blame]96.. kernel-doc:: include/efi_variable.h
97 :internal:
Heinrich Schuchardtc0b352e2019-07-14 14:05:37 +0200[diff] [blame]98.. kernel-doc:: lib/efi_loader/efi_variable.c
99 :internal:
100
101UEFI drivers
102------------
103
104UEFI driver uclass
105~~~~~~~~~~~~~~~~~~
106.. kernel-doc:: lib/efi_driver/efi_uclass.c
107 :internal:
108
109Block device driver
110~~~~~~~~~~~~~~~~~~~
111
112.. kernel-doc:: lib/efi_driver/efi_block_device.c
113 :internal:
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]114
115Protocols
116---------
117
118Block IO protocol
119~~~~~~~~~~~~~~~~~
120
121.. kernel-doc:: lib/efi_loader/efi_disk.c
122 :internal:
123
124File protocol
125~~~~~~~~~~~~~
126
127.. kernel-doc:: lib/efi_loader/efi_file.c
128 :internal:
129
130Graphical output protocol
131~~~~~~~~~~~~~~~~~~~~~~~~~
132
133.. kernel-doc:: lib/efi_loader/efi_gop.c
134 :internal:
135
Heinrich Schuchardt71a7de42020-02-22 07:47:20 +0100[diff] [blame]136Load file 2 protocol
137~~~~~~~~~~~~~~~~~~~~
138
139The load file 2 protocol can be used by the Linux kernel to load the initial
140RAM disk. U-Boot can be configured to provide an implementation.
141
142.. kernel-doc:: lib/efi_loader/efi_load_initrd.c
143 :internal:
144
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]145Network protocols
146~~~~~~~~~~~~~~~~~
147
148.. kernel-doc:: lib/efi_loader/efi_net.c
149 :internal:
150
Heinrich Schuchardtd417b942020-01-09 20:49:44 +0100[diff] [blame]151Random number generator protocol
152~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
153
154.. kernel-doc:: lib/efi_loader/efi_rng.c
155 :internal:
156
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]157Text IO protocols
158~~~~~~~~~~~~~~~~~
159
160.. kernel-doc:: lib/efi_loader/efi_console.c
161 :internal:
Heinrich Schuchardt76956552020-04-10 17:39:23 +0200[diff] [blame]162
163Unicode Collation protocol
164~~~~~~~~~~~~~~~~~~~~~~~~~~
165
166.. kernel-doc:: lib/efi_loader/efi_unicode_collation.c
167 :internal:
Heinrich Schuchardt7fec2492020-05-09 07:33:43 +0200[diff] [blame]168
169Unit testing
170------------
171
172The following library functions are provided to support writing UEFI unit tests.
173The should not be used elsewhere.
174
175.. kernel-doc:: include/efi_selftest.h
176 :internal: