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EFIRT(9) FreeBSD Kernel Developer's Manual EFIRT(9)
NAME
efirt, efi_rt_ok, efi_get_table, efi_get_time, efi_get_time_capabilities,
efi_reset_system, efi_set_time, efi_var_get, efi_var_nextname,
efi_var_set - kernel access to UEFI runtime services
SYNOPSIS
options EFIRT
#include <sys/efi.h>
int
efi_rt_ok(void);
int
efi_get_table(struct uuid *uuid, void **ptr);
int
efi_get_time(struct efi_tm *tm);
int
efi_get_time_capabilities(struct efi_tmcap *tmcap);
int
efi_reset_system(enum efi_reset type);
int
efi_set_time(struct efi_tm *tm);
int
efi_var_get(uint16_t *name, struct uuid *vendor, uint32_t *attrib,
size_t *datasize, void *data);
int
efi_var_nextname(size_t *namesize, uint16_t *name, struct uuid *vendor);
int
efi_var_set(uint16_t *name, struct uuid *vendor, uint32_t attrib,
size_t datasize, void *data);
DESCRIPTION
All of the following calls will return ENXIO if UEFI runtime services are
not available. efirt is currently only available on amd64 and arm64.
The efi_rt_ok() Returns 0 if UEFI runtime services are present and
functional, or ENXIO if not.
The efi_get_table() function gets a table by uuid from the UEFI system
table. Returns 0 if the table was found and populates *ptr with the
address. Returns ENXIO if the configuration table or system table are
unset. Returns ENOENT if the requested table cannot be found.
The efi_get_time() function gets the current time from the RTC, if
available. Returns 0 and populates the struct efi_tm on success.
Returns EINVAL if the struct efi_tm is NULL, or EIO if the time could not
be retrieved due to a hardware error.
The efi_get_time_capabilities() function gets the capabilities from the
EFI_RESET_COLD Perform a cold reset of the system, and reboot.
EFI_RESET_WARM Perform a warm reset of the system, and reboot.
EFI_RESET_SHUTDOWN Power off the system.
The efi_set_time() function sets the time on the RTC to the time
described by the struct efi_tm passed in. Returns 0 on success, EINVAL
if a time field is out of range, or EIO if the time could not be set due
to a hardware error.
The efi_var_get() function fetches the variable identified by vendor and
name. Returns 0 and populates attrib, datasize, and data on success.
Otherwise, one of the following errors are returned:
ENOENT The variable was not found.
EOVERFLOW datasize is not sufficient to hold the variable data.
namesize is updated to reflect the size needed to complete the
request.
EINVAL One of name, vendor, or datasize are NULL. Alternatively,
datasize is large enough to hold the response but data is
NULL.
EIO The variable could not be retrieved due to a hardware error.
EDOOFUS The variable could not be retireved due to an authentication
failure.
The efi_var_nextname() function is used for enumeration of variables. On
the initial call to efi_var_nextname(), name should be an empty string.
Subsequent calls should pass in the last name and vendor returned until
ENOENT is returned. Returns 0 and populates namesize, name, and vendor
with the next variable's data. Otherwise, returns one of the following
errors:
ENOENT The next variable was not found.
EOVERFLOW datasize is not sufficient to hold the variable data.
namesize is updated to reflect the size needed to complete the
request.
EINVAL One of name, vendor, or datasize are NULL.
EIO The variable could not be retrieved due to a hardware error.
The efi_var_set() function sets the variable described by name and
vendor. Returns 0 if the variable has been successfully. Otherwise,
returns one of the following errors:
EINVAL Either attrib was an invalid combination of attributes,
datasize exceeds the maximum allowed size, or name is an empty
Unicode stirng.
EAGAIN Not enough storage is available to hold the variable and its
data.
EIO The variable could not be saved due to a hardware error.
SEE ALSO
efidev(4)
AUTHORS
This manual page was written by Kyle Evans <kevans@FreeBSD.org>.
FreeBSD 14.0-RELEASE-p6 November 2, 2021 FreeBSD 14.0-RELEASE-p6