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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 04286d073e6eee1db089e92837ba184a91d8846c / . / doc / api / efi.rst
blob: 631c0ceb1df1288824293499317dc8b668d29a28 [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 Schuchardt04459782018-07-29 13:45:47 +0200[diff] [blame]81Runtime services
82----------------
83
84.. kernel-doc:: lib/efi_loader/efi_runtime.c
85 :internal:
Heinrich Schuchardtc0b352e2019-07-14 14:05:37 +0200[diff] [blame]86
87Variable services
88~~~~~~~~~~~~~~~~~
89
90.. kernel-doc:: lib/efi_loader/efi_variable.c
91 :internal:
92
93UEFI drivers
94------------
95
96UEFI driver uclass
97~~~~~~~~~~~~~~~~~~
98.. kernel-doc:: lib/efi_driver/efi_uclass.c
99 :internal:
100
101Block device driver
102~~~~~~~~~~~~~~~~~~~
103
104.. kernel-doc:: lib/efi_driver/efi_block_device.c
105 :internal:
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]106
107Protocols
108---------
109
110Block IO protocol
111~~~~~~~~~~~~~~~~~
112
113.. kernel-doc:: lib/efi_loader/efi_disk.c
114 :internal:
115
116File protocol
117~~~~~~~~~~~~~
118
119.. kernel-doc:: lib/efi_loader/efi_file.c
120 :internal:
121
122Graphical output protocol
123~~~~~~~~~~~~~~~~~~~~~~~~~
124
125.. kernel-doc:: lib/efi_loader/efi_gop.c
126 :internal:
127
Heinrich Schuchardt71a7de42020-02-22 07:47:20 +0100[diff] [blame]128Load file 2 protocol
129~~~~~~~~~~~~~~~~~~~~
130
131The load file 2 protocol can be used by the Linux kernel to load the initial
132RAM disk. U-Boot can be configured to provide an implementation.
133
134.. kernel-doc:: lib/efi_loader/efi_load_initrd.c
135 :internal:
136
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]137Network protocols
138~~~~~~~~~~~~~~~~~
139
140.. kernel-doc:: lib/efi_loader/efi_net.c
141 :internal:
142
Heinrich Schuchardtd417b942020-01-09 20:49:44 +0100[diff] [blame]143Random number generator protocol
144~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
145
146.. kernel-doc:: lib/efi_loader/efi_rng.c
147 :internal:
148
Heinrich Schuchardtfe1a81c2019-09-05 20:37:13 +0200[diff] [blame]149Text IO protocols
150~~~~~~~~~~~~~~~~~
151
152.. kernel-doc:: lib/efi_loader/efi_console.c
153 :internal: