acpi

1 files changed, 323 insertions, 0 deletions

diff --git a/kernel/drivers/acpi.c b/kernel/drivers/acpi.c
new file mode 100644
index 0000000..a222523
--- /dev/null
+++ b/kernel/drivers/acpi.c
@@ -0,0 +1,323 @@
+#include <lib.h>
+#include <comus/drivers/acpi.h>
+#include <comus/asm.h>
+#include <comus/memory.h>
+
+struct acpi_header {
+	uint32_t signature;
+	uint32_t length;
+	uint8_t revision;
+	uint8_t checksum;
+	uint8_t oem_id[6];
+	uint8_t oem_table_id[8];
+	uint32_t oem_revision;
+	uint32_t creator_id;
+	uint32_t creator_revision;
+} __attribute__((packed));
+
+// root system descriptor pointer
+// ACPI 1.0
+struct rsdp {
+	uint8_t signature[8];
+	uint8_t checksum;
+	uint8_t oemid[6];
+	uint8_t revision;
+	uint32_t rsdt_addr;
+} __attribute__((packed));
+
+// eXtended system descriptor pointer
+// ACPI 2.0
+struct xsdp {
+	char signature[8];
+	uint8_t checksum;
+	char oemid[6];
+	uint8_t revision;
+	uint32_t rsdt_addr;
+	uint32_t length;
+	uint64_t xsdt_addr;
+	uint8_t extendeid_checksum;
+	uint8_t reserved[3];
+} __attribute__((packed));
+
+// root system descriptor table
+// ACPI 1.0
+struct rsdt {
+	struct acpi_header h;
+	uint32_t sdt_pointers[];
+} __attribute__((packed));
+
+// eXtended system descriptor table
+// ACPI 2.0
+struct xsdt {
+	struct acpi_header h;
+	uint64_t sdt_pointers[];
+} __attribute__((packed));
+
+
+// generic address structure
+struct gas {
+	uint8_t address_space;
+	uint8_t bit_width;
+	uint8_t bit_offset;
+	uint8_t access_size;
+	uint64_t address;
+};
+
+// differentiated system description table
+struct dsdt {
+	struct acpi_header h;
+	char s5_addr[];
+} __attribute__((packed));
+
+struct apic {
+	struct acpi_header h;
+	// todo
+} __attribute__((packed));
+
+struct hept {
+	struct acpi_header h;
+	// todo
+} __attribute__((packed));
+
+struct waet {
+	struct acpi_header h;
+	// todo
+} __attribute__((packed));
+
+// fixed acpi description table
+struct fadt {
+	struct acpi_header h;
+	uint32_t firmware_ctrl;
+	uint32_t dsdt;
+
+	// field used in ACPI 1.0; no longer in use, for compatibility only
+	uint8_t  reserved;
+
+	uint8_t  preferred_power_management_profile;
+	uint16_t sci_interrupt;
+	uint32_t smi_command_port;
+	uint8_t  acpi_enable;
+	uint8_t  acpi_disable;
+	uint8_t  s4bios_req;
+	uint8_t  pstate_control;
+	uint32_t pm1_a_event_block;
+	uint32_t pm1_b_event_block;
+	uint32_t pm1_a_control_block;
+	uint32_t pm1_b_control_block;
+	uint32_t pm2_control_block;
+	uint32_t pm_timer_block;
+	uint32_t gpe0_block;
+	uint32_t gpe1_block;
+	uint8_t  pm1_event_length;
+	uint8_t  pm1_control_length;
+	uint8_t  pm2_control_length;
+	uint8_t  pm_timer_length;
+	uint8_t  gpe0_length;
+	uint8_t  gpe1_length;
+	uint8_t  gpe1_base;
+	uint8_t  cstate_control;
+	uint16_t worst_c2_latency;
+	uint16_t worst_c3_latency;
+	uint16_t flush_size;
+	uint16_t flush_stride;
+	uint8_t  duty_offset;
+	uint8_t  duty_width;
+	uint8_t  day_alarm;
+	uint8_t  month_alarm;
+	uint8_t  century;
+
+	// reserved in ACPI 1.0; used since ACPI 2.0+
+	uint16_t boot_architecture_flags;
+
+	uint8_t  reserved_2;
+	uint32_t flags;
+
+	// 12 byte structure; see below for details
+	struct gas reset_reg;
+
+	uint8_t  reset_value;
+	uint8_t  reserved_3[3];
+
+	// 64bit pointers - Available on ACPI 2.0+
+	uint64_t x_firmware_control;
+	uint64_t x_dsdt;
+
+	struct gas x_pm1_a_event_block;
+	struct gas x_pm1_b_event_block;
+	struct gas x_pm1_a_control_block;
+	struct gas x_pm1_b_control_block;
+	struct gas x_pm2_control_block;
+	struct gas x_pm_timer_block;
+	struct gas x_gpe0_block;
+	struct gas x_gpe1_block;
+} __attribute__((packed));
+
+struct acpi_state {
+	union {
+		struct xsdt *xsdt;
+		struct rsdt *rsdt;
+	} sdt;
+	struct fadt *fadt;
+	struct dsdt *dsdt;
+	struct apic *apic;
+	struct hept *hept;
+	struct waet *waet;
+	uint8_t version;
+
+	uint16_t SLP_TYPa;
+	uint16_t SLP_TYPb;
+	uint16_t SLP_EN;
+	uint16_t SCI_EN;
+};
+
+/* global state, idk a better way rn */
+static struct acpi_state state;
+
+static bool checksum(uint8_t *data, size_t len) {
+	unsigned char sum = 0;
+	for (size_t i = 0; i < len; i++)
+		sum += data[i];
+	return sum == 0;
+}
+
+static int read_s5_addr(struct dsdt *dsdt) {
+	char *s5_addr = dsdt->s5_addr;
+	int dsdt_len = dsdt->h.length - sizeof(struct acpi_header);
+
+	while (0 < dsdt_len--) {
+		if (memcmp(s5_addr, "_S5_", 4) == 0)
+			break;
+		s5_addr++;
+	}
+
+	if (dsdt_len > 0) {
+		// check for valid AML structure
+		if ( ( *(s5_addr-1) == 0x08 || ( *(s5_addr-2) == 0x08 && *(s5_addr-1) == '\\') ) && *(s5_addr+4) == 0x12 ) {
+			s5_addr += 5;
+			s5_addr += ((*s5_addr &0xC0)>>6) +2;   // calculate PkgLength size
+
+			if (*s5_addr == 0x0A)
+				s5_addr++;   // skip byteprefix
+			state.SLP_TYPa = *(s5_addr)<<10;
+			s5_addr++;
+
+			if (*s5_addr == 0x0A)
+				s5_addr++;   // skip byteprefix
+			state.SLP_TYPb = *(s5_addr)<<10;
+
+			state.SLP_EN = 1<<13;
+			state.SCI_EN = 1;
+
+		} else {
+			return -1;
+		}
+	} else {
+		return -1;
+	}
+
+	return -1;
+}
+
+static void acpi_load_table(uint64_t addr);
+
+static void acpi_load_rsdt_tables(struct rsdt *rsdt) {
+	int entries = (rsdt->h.length - sizeof(rsdt->h)) / 4;
+	for (int i = 0; i < entries; i++) {
+		uint32_t addr = rsdt->sdt_pointers[i];
+		acpi_load_table(addr);
+	}
+}
+
+static void acpi_load_xsdt_tables(struct xsdt *xsdt) {
+	int entries = (xsdt->h.length - sizeof(xsdt->h)) / 8;
+	for (int i = 0; i < entries; i++) {
+		uint64_t addr = xsdt->sdt_pointers[i];
+		acpi_load_table(addr);
+	}
+}
+
+#define SIG_RSDT    0x54445352
+#define SIG_XSDT    0x54445358
+#define SIG_FACP    0x50434146
+#define SIG_DSDT    0x54445344
+#define SIG_APIC    0x43495041
+#define SIG_HEPT    0x54455048
+#define SIG_WAET    0x54454157
+
+static void acpi_handle_table(struct acpi_header *header) {
+	switch (header->signature) {
+		case SIG_RSDT:
+			state.sdt.rsdt = (struct rsdt *) header;
+			acpi_load_rsdt_tables(state.sdt.rsdt);
+			break;
+		case SIG_XSDT:
+			state.sdt.xsdt = (struct xsdt *) header;
+			acpi_load_xsdt_tables(state.sdt.xsdt);
+			break;
+		case SIG_FACP:
+			state.fadt = (struct fadt *) header;
+			acpi_load_table(state.fadt->dsdt);
+			break;
+		case SIG_DSDT:
+			state.dsdt = (struct dsdt *) header;
+			read_s5_addr(state.dsdt);
+			break;
+		case SIG_APIC:
+			state.apic = (struct apic *) header;
+			break;
+		case SIG_HEPT:
+			state.hept = (struct hept *) header;
+			break;
+		case SIG_WAET:
+			state.waet = (struct waet *) header;
+			break;
+		default:
+			break;
+	}
+}
+
+static void acpi_load_table(uint64_t addr) {
+	struct acpi_header *temp, *mapped;
+	uint32_t length;
+	temp = (struct acpi_header * ) (uintptr_t) addr;
+	mapped = kmapaddr(temp, sizeof(struct acpi_header));
+	length = mapped->length;
+	kunmapaddr(mapped);
+	mapped = kmapaddr(temp, length);
+	if (!checksum((uint8_t *) mapped, mapped->length)) {
+		kunmapaddr(mapped);
+		return;
+	}
+	kprintf("%.*s: %#016lx\n", 4, (char*)&mapped->signature, (size_t)temp);
+	acpi_handle_table(mapped);
+}
+
+void acpi_init(void *rootsdp) {
+	memset(&state, 0, sizeof(struct acpi_state));
+	struct rsdp *rsdp = (struct rsdp *) rootsdp;
+	if (!checksum((uint8_t *)rsdp, sizeof(struct rsdp))) {
+		panic("invalid acpi rsdp checksum");
+	}
+	if (memcmp(rsdp->signature, "RSD PTR ", 8) != 0) {
+		panic("invalid acpi rsdp signature: %.*s\n", 8, rsdp->signature);
+	}
+	if (rsdp->revision == 0) {
+		state.version = 0;
+		kprintf("ACPI 1.0\n");
+		acpi_load_table(rsdp->rsdt_addr);
+	} else if (rsdp->revision == 2) {
+		state.version = 2;
+		struct xsdp *xsdp = (struct xsdp *) rsdp;
+		kprintf("ACPI 2.0\n");
+		acpi_load_table(xsdp->xsdt_addr);
+	} else {
+		panic("invalid acpi rev: %d\n", rsdp->revision);
+	}
+	kprintf("\n");
+	outb(state.fadt->smi_command_port, state.fadt->acpi_enable);
+}
+
+void acpi_shutdown(void) {
+	outw((unsigned int) state.fadt->pm1_a_control_block, state.SLP_TYPb | state.SLP_EN);
+	panic("ACPI shutdown failed");
+}