ACPI Namespace Reference

Abstracts the ACPI standard that provides interfaces for hardware detection, device configuration, and energy management. More...

Namespaces
namespace	MADS

Classes
struct	Address
	ACPI address format. More...

Enumerations
enum class	AddressSpace : uint8_t {   MEMORY = 0x0 ,   IO = 0x1 }

Functions
static int	checksum (const void *pos, unsigned len)
static const RSDP *	findRSDP (const void *pos, unsigned len)
bool	init ()
	Initialize the ACPI description table.
unsigned	count ()
	Number of entries in the description table.
SDTH *	get (unsigned num)
	Get entry of description table by index.
SDTH *	get (char a, char b, char c, char d)
	Get entry of description table by four character identifier.
int	revision ()
	Retrieve the revision from the Root System Description Pointer (RSDP)

Constants
static RSDP *	rsdp = 0
static RSDT *	rsdt = 0
static XSDT *	xsdt = 0
const char *	RSDP_SIGNATURE = "RSD PTR "

Detailed Description

Abstracts the ACPI standard that provides interfaces for hardware detection, device configuration, and energy management.

ACPI is the successor to APM (Advanced Power Management), aiming to give the operating system more control over the hardware. This extended control, for instance, enables the operating system to assign a particular amount of energy to every device (e.g., by disabling a device or changing to standby mode). For this purpose, BIOS and chipset provide a set of tables that describe the system and its components and provide routines the OS can call. These tables contain details about the system, such as the number of CPU cores and the LAPIC/IOAPIC, which are determined during system boot.

Enumeration Type Documentation

AddressSpace

enum class ACPI::AddressSpace : uint8_t

strong

Enumerator
MEMORY
IO

Function Documentation

checksum()

static int ACPI::checksum ( const void *  pos, unsigned  len  )

static

findRSDP()

static const RSDP * ACPI::findRSDP ( const void *  pos, unsigned  len  )

static

init()

bool ACPI::init

(

)

Initialize the ACPI description table.

Searches physical memory ranges o 16-byte boundaries for a valid Root System Description Pointer (RSDP) structure signature and checksum. If present, the superseding Extended System Description Table (XSDT) is used.

See also

ACPI-Specification 5.2.5 Root System Description Pointer (RSDP)

ACPI-Specification 5.2.8 Extended System Description Table (XSDT)

count()

unsigned ACPI::count

(

)

Number of entries in the description table.

get() [1/2]

SDTH * ACPI::get

(

unsigned

num

)

Get entry of description table by index.

Parameters

num	index in description table

Returns

Pointer to corresponding entry or nullptr if not available

get() [2/2]

SDTH * ACPI::get	(	char	a,
		char	b,
		char	c,
		char	d
	)

Get entry of description table by four character identifier.

Parameters

a	first character of identifier
b	second character of identifier
c	third character of identifier
d	forth and last character of identifier

Returns

Pointer to corresponding entry or nullptr if not available

revision()

int ACPI::revision

(

)

Retrieve the revision from the Root System Description Pointer (RSDP)

Constant Documentation

rsdp

RSDP* ACPI::rsdp = 0

static

rsdt

RSDT* ACPI::rsdt = 0

static

xsdt

XSDT* ACPI::xsdt = 0

static

RSDP_SIGNATURE

const char* ACPI::RSDP_SIGNATURE = "RSD PTR "