NAME
efidev, efirtc
— user-mode access to UEFI
runtime services
SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:
options EFIRTAlternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
efirt_load="YES"
The driver may be disabled by setting the
loader(8) tunable efi.rt.disabled to
“1”.
DESCRIPTION
Theefidev device provides user-mode access to UEFI
runtime services. efidev 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.
efidev provides the following ioctls
defined in <sys/efiio.h>
with supplemental structures and constants defined in
<sys/efi.h>:
EFIIOC_GET_TABLE(struct efi_get_table_ioc)- Get a table by uuid from the UEFI system table.
struct efi_get_table_ioc { struct uuid uuid; void *ptr; }; EFIIOC_GET_TIME(struct efi_tm)- Get the time from the RTC, if the RTC is available. The
struct efi_tm passed is populated with the current
time, unless an error occurs.
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; }; EFIIOC_SET_TIME(struct efi_tm)- Sets the time stored by the RTC, if the RTC is available.
EFIIOC_VAR_GET(struct efi_var_ioc)- Gets data from the variable described by the vendor and name fields of the
struct efi_var_ioc into the
data field.
EFIIOC_VAR_GET(struct efi_var_ioc) will also populate the attrib field.struct efi_var_ioc { efi_char *name; size_t namesize; struct uuid vendor; uint32_t attrib; void *data; size_t datasize; }; EFIIOC_VAR_NEXT(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.
EFIIOC_VAR_SET(struct efi_var_ioc)- Sets data and attributes for the variable described by the name and vendor in the struct efi_var_ioc.
FILES
- /dev/efi
SEE ALSO
HISTORY
A efidev device first appeared in
FreeBSD 11.1.
BUGS
efidev is currently only available on
amd64 and arm64.