1.\"- 2.\" SPDX-License-Identifier: BSD-2-Clause 3.\" 4.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd June 18, 2021 30.Dt EFIDEV 4 31.Os 32.Sh NAME 33.Nm efidev , 34.Nm efirtc 35.Nd user-mode access to UEFI runtime services 36.Sh SYNOPSIS 37To compile this driver into the kernel, place the following lines in your 38kernel configuration file: 39.Bd -ragged -offset -indent 40.Cd "options EFIRT" 41.Ed 42.Pp 43Alternatively, to load the driver as a module at boot time, place the following 44line in 45.Xr loader.conf 5 : 46.Bd -literal -offset indent 47efirt_load="YES" 48.Ed 49.Pp 50The driver may be disabled by setting the 51.Xr loader 8 52tunable 53.Va efi.rt.disabled 54to 55.Dq Li 1 . 56.Sh DESCRIPTION 57The 58.Nm 59device provides user-mode access to UEFI runtime services. 60.Nm 61also includes a driver to provide a time-of-day clock using the UEFI 62real time clock (RTC). 63However, the RTC may not always be available, based on the UEFI firmware. 64If the RTC is not available, it will not be registered as a time-of-day clock 65and the time related ioctls below will not be functional. 66.Pp 67.Nm 68provides the following ioctls defined in 69.In sys/efiio.h 70with supplemental structures and constants defined in 71.In sys/efi.h : 72.Bl -tag -width indent 73.It Dv EFIIOC_GET_TABLE Pq Vt "struct efi_get_table_ioc" 74Copy the UEFI table specified by the 75.Va uuid 76field of the 77.Vt struct efi_get_table_ioc 78into the 79.Va buf 80field. 81The memory size for the buf field can be queried by passing 82.Dv NULL 83pointer as a buf value. 84The required size will be stored in the 85.Va table_len 86field. 87The size of the allocated memory must be specified in the 88.Va buf_len 89field. 90.Bd -literal -offset indent 91struct efi_get_table_ioc { 92 void *buf; 93 struct uuid uuid; 94 size_t table_len; 95 size_t buf_len; 96}; 97.Ed 98.It Dv EFIIOC_GET_TIME Pq Vt "struct efi_tm" 99Get the time from the RTC, if the RTC is available. 100The 101.Vt struct efi_tm 102passed is populated with the current time, unless an error occurs. 103.Bd -literal -offset indent 104struct efi_tm { 105 uint16_t tm_year; 106 uint8_t tm_mon 107 uint8_t tm_mday 108 uint8_t tm_hour; 109 uint8_t tm_min; 110 uint8_t tm_sec; 111 uint8_t __pad1; 112 uint32_t tm_nsec; 113 int16_t tm_tz; 114 uint8_t tm_dst; 115 uint8_t __pad2; 116}; 117.Ed 118.It Dv EFIIOC_SET_TIME Pq Vt "struct efi_tm" 119Sets the time stored by the RTC, if the RTC is available. 120.It Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc" 121Gets data from the variable described by the vendor and name fields of the 122.Vt struct efi_var_ioc 123into the 124.Fa data 125field. 126.Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc" 127will also populate the 128.Fa attrib 129field. 130.Bd -literal 131struct efi_var_ioc { 132 efi_char *name; 133 size_t namesize; 134 struct uuid vendor; 135 uint32_t attrib; 136 void *data; 137 size_t datasize; 138}; 139.Ed 140.It Dv EFIIOC_VAR_NEXT Pq Vt "struct efi_var_ioc" 141Used for enumerating all UEFI variables. 142The initial call should use an empty string for the name attribute. 143Subsequent calls should supply the vendor uuid and name of the last variable 144returned. 145.It Dv EFIIOC_VAR_SET Pq Vt "struct efi_var_ioc" 146Sets data and attributes for the variable described by the name and vendor in 147the 148.Vt struct efi_var_ioc . 149.El 150.Sh FILES 151.Bl -tag -width /dev/efi 152.It Pa /dev/efi 153.El 154.Sh SEE ALSO 155.Xr efivar 3 , 156.Xr efirt 9 157.Sh HISTORY 158A 159.Nm 160device first appeared in 161.Fx 11.1 . 162.Sh BUGS 163.Nm 164is currently only available on amd64 and arm64. 165