x86_64: add a basic ACPI driver

arch/x86_64/include/arch/acpi.h

@@ -0,0 +1,61 @@
+#ifndef ARCH_ACPI_H_
+#define ARCH_ACPI_H_
+
+#include <socks/compiler.h>
+#include <socks/status.h>
+#include <stdint.h>
+
+#define ACPI_SIG_RSDP 0x2052545020445352ULL
+#define ACPI_SIG_FADT 0x50434146
+
+struct acpi_rsdp_10 {
+	char r_sig[8];
+	uint8_t r_chksum;
+	char r_oem[6];
+	uint8_t r_revision;
+	uint32_t r_rsdt_ptr;
+} __packed;
+
+struct acpi_rsdp_20 {
+	struct acpi_rsdp_10 r_base;
+
+	uint32_t r_length;
+	uint64_t r_xsdt_ptr;
+	uint8_t r_chksum_ext;
+	uint8_t r_reserved[3];
+} __packed;
+
+struct acpi_rsdp {
+	union {
+		struct acpi_rsdp_10 rsdp_10;
+		struct acpi_rsdp_20 rsdp_20;
+	};
+} __packed;
+		  
+struct acpi_sdt {
+	char s_sig[4];
+	uint32_t s_length;
+	uint8_t s_revision;
+	uint8_t s_chksum;
+	char s_oem[6];
+	char s_oem_table[8];
+	uint32_t s_oem_revision;
+	uint32_t s_creator;
+	uint32_t s_creator_revision;
+} __packed;
+
+struct acpi_rsdt {
+	struct acpi_sdt r_header;
+	uint32_t r_tables[];
+} __packed;
+
+struct acpi_xsdt {
+	struct acpi_sdt x_header;
+	uint64_t x_tables[];
+} __packed;
+
+extern kern_status_t acpi_init(void);
+
+extern struct acpi_sdt *acpi_find_sdt(uint32_t sig);
+
+#endif