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. More...

Classes
struct	Address
	ACPI address format. More...

struct	MADT
	Multiple APIC Description Table (MADT) More...

struct	RSDP
	Root System Description Pointer (RSDP) More...

struct	RSDT
	Root System Description Table (RSDT) More...

struct	SDTH
	System Description Table Header (SDTH) More...

struct	SubHeader
	Helper structure. More...

struct	XSDT
	Extended System Description Table (XSDT) More...

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

Functions
bool	init ()

unsigned	count ()

SDTH *	get (unsigned num)

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

int	revision ()

Variables
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.

Class Documentation

◆ ACPI::Address

struct ACPI::Address

ACPI address format.

The ACPI standard defines its own address format that is able to handle addresses both in memory address space, as well as IO-port address space.

Class Members
AddressSpace	address_space
uint8_t	register_bit_width
uint8_t	register_bit_offset
uint8_t	reserved
uint64_t	address

◆ ACPI::RSDP

struct ACPI::RSDP

Root System Description Pointer (RSDP)

The first step to using ACPI is finding the RSDP that is used to find the RSDT / XSDT, which themselves contain pointers to even more tables.

On UEFI systems, the RSDP can be found in the EFI_SYSTEM_TABLE; for non-UEFI systems we have to search for the signature 'RSD PTR ' in the EBDA (Extended Bios Data Area) or in the memory area to bis FFFFFh.

See also: ACPI-Specification 5.2.5.3; Root System Description Pointer (RSDP) Structure

Class Members
char	signature[8]
uint8_t	checksum
char	oemid[6]
uint8_t	revision
uint32_t	rsdtaddress
uint32_t	length
uint64_t	xsdtaddress
uint8_t	extended_checksum
uint8_t	reserved[3]

Classes

Enumerations

Functions

Variables

Detailed Description

Class Documentation

◆ ACPI::Address

◆ ACPI::RSDP