DMI_FIELD_BITS
Synopsis
#include <opendmi/field.h>
DMI_FIELD_BITS(structure, member, bits, ...)
DMI_FIELD_BITS_SKIP(bits)
DMI_FIELD_PAD(unit_type)Description
The macros declare the fields which share the bits of a byte, a word or a
wider unit, e.g. the flags of a structure, see DMI_FIELD.
DMI_FIELD_BITS-
Range of
bitsbits, read intomember. Ranges are taken from the least significant bit of the unit up, in the order they are declared, and a range is allowed to span the bytes of the unit, the way the bit fields of a little-endian value do. DMI_FIELD_BITS_SKIP-
Range of
bitsbits the specification reserves between the ranges, which carries no value. On encoding, it holds what the source data had in the preserve mode, and zeros in the canonical one. DMI_FIELD_PAD-
Bits left over at the end of the unit, of the type
unit_type, e.g.dmi_word_t, which close it. Every run of ranges ends with one, and no field of another kind begins in the middle of a unit.
Versions of ranges
A version of the specification may give a meaning to the reserved bits of a
unit the structure already holds, which says nothing about its length: the
version the entry point declares decides it. Such a range declares the version
it is defined from as .from, and is left to the padding of the unit in the
tables of an earlier version. A range the version widens is declared twice, up
to the version with .before, and from it with .from, both reading into one
member.
Parameters
structure,member-
Structure and member the range is read into.
bits-
Width of the range, in bits.
unit_type-
Type of the unit, whose size gives its width.
…-
Further parameters, given as the designated initializers of
dmi_field_params_t:.fromand.before, and the.decodeand.encodehandlers, seeDMI_FIELD.
Example
DMI_FIELD_BITS(dmi_hpe_trusted_module_t, presence, 2),
DMI_FIELD_BITS(dmi_hpe_trusted_module_t, is_orom_measuring, 1),
DMI_FIELD_BITS(dmi_hpe_trusted_module_t, is_hidden, 1),
DMI_FIELD_PAD(dmi_byte_t),