freebsd-dev/share/man/man4/efidev.4
Mateusz Piotrowski 2f4146c5d4 efidev.4: Improve formatting.
- Move some information out of the SYNOPSIS section because it is formated
  in a broken way by mandoc(1) otherwise.
- Improve the formatting of the list of provided ioctls.
- Use "Fa" for struct fields.
- Pet mandoc and igor.
- Fix typos.

Reviewed by:	kevans
Approved by:	mat (mentor)
Differential Revision:	https://reviews.freebsd.org/D16765
2018-08-20 22:16:15 +00:00

148 lines
4.2 KiB
Groff

.\"-
.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
.\"
.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
.\"
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.\" modification, are permitted provided that the following conditions
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.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" $FreeBSD$
.\"
.Dd August 12, 2018
.Dt EFIDEV 4
.Os
.Sh NAME
.Nm efidev ,
.Nm efirtc
.Nd user-mode access to UEFI runtime services
.Sh SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
.Bd -ragged -offset -indent
.Cd "options EFIRT"
.Ed
.Pp
Alternatively, to load the driver as a module at boot time, place the following
line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
efirt_load="YES"
.Ed
.Pp
The driver may be disabled by setting the
.Xr loader 8
tunable
.Va efi.rt.disabled
to
.Dq Li 1 .
.Sh DESCRIPTION
The
.Nm
device provides user-mode access to UEFI runtime services.
.Nm
also includes a driver to provide a time-of-day clock using the UEFI
real time clock (RTC).
However, the RTC may not always be available, based on the UEFI firmware.
If the RTC is not available, it will not be registered as a time-of-day clock
and the time related ioctls below will not be functional.
.Pp
.Nm
provides the following ioctls defined in
.In sys/efiio.h
with supplemental structures and constants defined in
.In sys/efi.h :
.Bl -tag -width indent
.It Dv EFIIOC_GET_TABLE Pq Vt "struct efi_get_table_ioc"
Get a table by uuid from the UEFI system table.
.Bd -literal -offset indent
struct efi_get_table_ioc {
struct uuid uuid;
void *ptr;
};
.Ed
.It Dv EFIIOC_GET_TIME Pq Vt "struct efi_tm"
Get the time from the RTC, if the RTC is available.
The
.Vt struct efi_tm
passed is populated with the current time, unless an error occurs.
.Bd -literal -offset indent
struct efi_tm {
uint16_t tm_year;
uint8_t tm_mon
uint8_t tm_mday
uint8_t tm_hour;
uint8_t tm_min;
uint8_t tm_sec;
uint8_t __pad1;
uint32_t tm_nsec;
int16_t tm_tz;
uint8_t tm_dst;
uint8_t __pad2;
};
.Ed
.It Dv EFIIOC_SET_TIME Pq Vt "struct efi_tm"
Sets the time stored by the RTC, if the RTC is available.
.It Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc"
Gets data from the variable described by the vendor and name fields of the
.Vt struct efi_var_ioc
into the
.Fa data
field.
.Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc"
will also populate the
.Fa attrib
field.
.Bd -literal
struct efi_var_ioc {
efi_char *name;
size_t namesize;
struct uuid vendor;
uint32_t attrib;
void *data;
size_t datasize;
};
.Ed
.It Dv EFIIOC_VAR_NEXT Pq Vt "struct efi_var_ioc"
Used for enumerating all UEFI variables.
The initial call should use an empty string for the name attribute.
Subsequent calls should supply the vendor uuid and name of the last variable
returned.
.It Dv EFIIOC_VAR_SET Pq Vt "struct efi_var_ioc"
Sets data and attributes for the variable described by the name and vendor in
the
.Vt struct efi_var_ioc .
.El
.Sh FILES
.Bl -tag -width /dev/efi
.It Pa /dev/efi
.El
.Sh SEE ALSO
.Xr efivar 3 ,
.Xr efirt 9
.Sh HISTORY
A
.Nm
device first appeared in
.Fx 11.1 .
.Sh BUGS
.Nm
is currently only available on amd64 and arm64.