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4 .\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
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33 .Nd user-mode access to UEFI runtime services
35 To compile this driver into the kernel, place the following lines in your
36 kernel configuration file:
37 .Bd -ragged -offset -indent
41 Alternatively, to load the driver as a module at boot time, place the following
44 .Bd -literal -offset indent
48 The driver may be disabled by setting the
57 device provides user-mode access to UEFI runtime services.
59 also includes a driver to provide a time-of-day clock using the UEFI
60 real time clock (RTC).
61 However, the RTC may not always be available, based on the UEFI firmware.
62 If the RTC is not available, it will not be registered as a time-of-day clock
63 and the time related ioctls below will not be functional.
66 provides the following ioctls defined in
68 with supplemental structures and constants defined in
70 .Bl -tag -width indent
71 .It Dv EFIIOC_GET_TABLE Pq Vt "struct efi_get_table_ioc"
72 Copy the UEFI table specified by the
75 .Vt struct efi_get_table_ioc
79 The memory size for the buf field can be queried by passing
81 pointer as a buf value.
82 The required size will be stored in the
85 The size of the allocated memory must be specified in the
88 .Bd -literal -offset indent
89 struct efi_get_table_ioc {
96 .It Dv EFIIOC_GET_TIME Pq Vt "struct efi_tm"
97 Get the time from the RTC, if the RTC is available.
100 passed is populated with the current time, unless an error occurs.
101 .Bd -literal -offset indent
116 .It Dv EFIIOC_SET_TIME Pq Vt "struct efi_tm"
117 Sets the time stored by the RTC, if the RTC is available.
118 .It Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc"
119 Gets data from the variable described by the vendor and name fields of the
120 .Vt struct efi_var_ioc
124 .Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc"
125 will also populate the
138 .It Dv EFIIOC_VAR_NEXT Pq Vt "struct efi_var_ioc"
139 Used for enumerating all UEFI variables.
140 The initial call should use an empty string for the name attribute.
141 Subsequent calls should supply the vendor uuid and name of the last variable
143 .It Dv EFIIOC_VAR_SET Pq Vt "struct efi_var_ioc"
144 Sets data and attributes for the variable described by the name and vendor in
146 .Vt struct efi_var_ioc .
149 .Bl -tag -width /dev/efi
158 device first appeared in
162 is currently only available on amd64 and arm64.