The
efidev
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)
|
| |
Copy the UEFI table specified by the
uuid
field of the
struct efi_get_table_ioc
into the
buf
field.
The memory size for the buf field can be queried by passing
NULL
pointer as a buf value.
The required size will be stored in the
table_len
field.
The size of the allocated memory must be specified in the
buf_len
field.
struct efi_get_table_ioc {
void *buf;
struct uuid uuid;
size_t table_len;
size_t buf_len;
};
|
| 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.
|
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