#ifndef ACPI_H_
#define ACPI_H_

#include <stdint.h>

#define BIOS_START   0x000E0000
#define BIOS_END     0x000FFFFF
#define RSDP_SIG     "RSD PTR "
#define RSDP_SIG_LEN 8
#define RSDP_SIZE    20

#define ACPI_VER_1      0
#define ACPI_VER_OTHER  2

struct rsdp {
    char Signature[RSDP_SIG_LEN];
    uint8_t Checksum;
    char OEMID[6];
    uint8_t Revision;
    uint32_t RsdtAddress;
} __attribute__ ((packed));

struct ACPISDTHeader {
  char Signature[4];
  uint32_t Length;
  uint8_t Revision;
  uint8_t Checksum;
  char OEMID[6];
  char OEMTableID[8];
  uint32_t OEMRevision;
  uint32_t CreatorID;
  uint32_t CreatorRevision;
};

struct rsdt {
  struct ACPISDTHeader h;
  uint32_t other_sdt[];
};

struct mcfg_entry {
    uint64_t base_addr;
    uint16_t pci_seg_num;
    uint8_t pci_bus_start;
    uint8_t pci_bus_end;
    uint32_t reserved;
};

struct mcfg {
    struct ACPISDTHeader h;
    uint64_t reserved;
    struct mcfg_entry entries[];
};

struct rsdp *acpi_search_for_rsdp();
int acpi_validate_rsdp_checksum(struct rsdp *s);
int acpi_validate_sdt_checksum(struct ACPISDTHeader *s);
struct ACPISDTHeader *acpi_find_table(struct rsdt *root, const char *signature);

#endif