limine/common/lib/acpi.c
2022-09-02 02:29:12 +02:00

241 lines
7.2 KiB
C

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <lib/acpi.h>
#include <lib/misc.h>
#include <lib/libc.h>
#include <lib/print.h>
// Following function based on https://github.com/managarm/lai/blob/master/helpers/pc-bios.c's function lai_bios_calc_checksum()
uint8_t acpi_checksum(void *ptr, size_t size) {
uint8_t sum = 0, *_ptr = ptr;
for (size_t i = 0; i < size; i++)
sum += _ptr[i];
return sum;
}
#if defined (BIOS)
void *acpi_get_rsdp(void) {
size_t ebda = EBDA;
for (size_t i = ebda; i < 0x100000; i += 16) {
if (i == ebda + 1024) {
// We probed the 1st KiB of the EBDA as per spec, move onto 0xe0000
i = 0xe0000;
}
if (!memcmp((char *)i, "RSD PTR ", 8)
&& !acpi_checksum((void *)i, 20)) {
printv("acpi: Found RSDP at %p\n", i);
return (void *)i;
}
}
return NULL;
}
/// Returns the RSDP v1 pointer if avaliable or else NULL.
void *acpi_get_rsdp_v1(void) {
// In BIOS according to the ACPI spec (see ACPI 6.2 section
// 5.2.5.1 'Finding the RSDP on IA-PC Systems') it either contains
// the RSDP or the XSDP and it cannot contain both. So, we directly
// use acpi_get_rsdp function to find the RSDP and if it has the correct
// revision, return it.
struct rsdp *rsdp = acpi_get_rsdp();
if (rsdp != NULL && rsdp->rev < 2)
return rsdp;
return NULL;
}
void acpi_get_smbios(void **smbios32, void **smbios64) {
*smbios32 = NULL;
*smbios64 = NULL;
for (size_t i = 0xf0000; i < 0x100000; i += 16) {
struct smbios_entry_point_32 *ptr = (struct smbios_entry_point_32 *)i;
if (!memcmp(ptr->anchor_str, "_SM_", 4) &&
!acpi_checksum((void *)ptr, ptr->length)) {
printv("acpi: Found SMBIOS 32-bit entry point at %p\n", i);
*smbios32 = (void *)ptr;
break;
}
}
for (size_t i = 0xf0000; i < 0x100000; i += 16) {
struct smbios_entry_point_64 *ptr = (struct smbios_entry_point_64 *)i;
if (!memcmp(ptr->anchor_str, "_SM3_", 5) &&
!acpi_checksum((void *)ptr, ptr->length)) {
printv("acpi: Found SMBIOS 64-bit entry point at %p\n", i);
*smbios64 = (void *)ptr;
break;
}
}
}
#endif
#if defined (UEFI)
#include <efi.h>
void *acpi_get_rsdp(void) {
EFI_GUID acpi_2_guid = ACPI_20_TABLE_GUID;
EFI_GUID acpi_1_guid = ACPI_TABLE_GUID;
void *rsdp = NULL;
for (size_t i = 0; i < gST->NumberOfTableEntries; i++) {
EFI_CONFIGURATION_TABLE *cur_table = &gST->ConfigurationTable[i];
bool is_xsdp = memcmp(&cur_table->VendorGuid, &acpi_2_guid, sizeof(EFI_GUID)) == 0;
bool is_rsdp = memcmp(&cur_table->VendorGuid, &acpi_1_guid, sizeof(EFI_GUID)) == 0;
if (!is_xsdp && !is_rsdp)
continue;
if ((is_xsdp && acpi_checksum(cur_table->VendorTable, sizeof(struct rsdp)) != 0) || // XSDP is 36 bytes wide
(is_rsdp && acpi_checksum(cur_table->VendorTable, 20) != 0)) // RSDP is 20 bytes wide
continue;
printv("acpi: Found %s at %p\n", is_xsdp ? "XSDP" : "RSDP", cur_table->VendorTable);
// We want to return the XSDP if it exists rather then returning
// the RSDP. We need to add a check for that since the table entries
// are not in the same order for all EFI systems since it might be the
// case where the RSDP ocurs before the XSDP.
if (is_xsdp) {
rsdp = (void *)cur_table->VendorTable;
break; // Found it!.
} else {
// Found the RSDP but we continue to loop since we might
// find the XSDP.
rsdp = (void *)cur_table->VendorTable;
}
}
return rsdp;
}
/// Returns the RSDP v1 pointer if avaliable or else NULL.
void *acpi_get_rsdp_v1(void) {
// To maintain GRUB compatibility we will need to probe for the RSDP
// again since UEFI can contain both XSDP and RSDP (see ACPI 6.2 section
// 5.2.5.2 'Finding the RSDP on UEFI Enabled Systems') and in the acpi_get_rsdp
// function we look for the RSDP with the latest revision.
EFI_GUID acpi_1_guid = ACPI_TABLE_GUID;
for (size_t i = 0; i < gST->NumberOfTableEntries; i++) {
EFI_CONFIGURATION_TABLE *cur_table = &gST->ConfigurationTable[i];
if (memcmp(&cur_table->VendorGuid, &acpi_1_guid, sizeof(EFI_GUID)) != 0)
continue;
if (acpi_checksum(cur_table->VendorTable, 20) != 0)
continue;
return (void *)cur_table->VendorTable;
}
return NULL;
}
void acpi_get_smbios(void **smbios32, void **smbios64) {
*smbios32 = NULL;
*smbios64 = NULL;
for (size_t i = 0; i < gST->NumberOfTableEntries; i++) {
EFI_CONFIGURATION_TABLE *cur_table = &gST->ConfigurationTable[i];
EFI_GUID smbios_guid = SMBIOS_TABLE_GUID;
if (memcmp(&cur_table->VendorGuid, &smbios_guid, sizeof(EFI_GUID)) != 0)
continue;
struct smbios_entry_point_32 *ptr = (struct smbios_entry_point_32 *)cur_table->VendorTable;
if (acpi_checksum((void *)ptr, ptr->length) != 0)
continue;
printv("acpi: Found SMBIOS 32-bit entry point at %X\n", ptr);
*smbios32 = (void *)ptr;
break;
}
for (size_t i = 0; i < gST->NumberOfTableEntries; i++) {
EFI_CONFIGURATION_TABLE *cur_table = &gST->ConfigurationTable[i];
EFI_GUID smbios3_guid = SMBIOS3_TABLE_GUID;
if (memcmp(&cur_table->VendorGuid, &smbios3_guid, sizeof(EFI_GUID)) != 0)
continue;
struct smbios_entry_point_64 *ptr = (struct smbios_entry_point_64 *)cur_table->VendorTable;
if (acpi_checksum((void *)ptr, ptr->length) != 0)
continue;
printv("acpi: Found SMBIOS 64-bit entry point at %X\n", ptr);
*smbios64 = (void *)ptr;
break;
}
}
#endif
/// Returns the RSDP v2 pointer if avaliable or else NULL.
void *acpi_get_rsdp_v2(void) {
// Since the acpi_get_rsdp function already looks for the XSDP we can
// just check if it has the correct revision and return the pointer :^)
struct rsdp *rsdp = acpi_get_rsdp();
if (rsdp != NULL && rsdp->rev >= 2)
return rsdp;
return NULL;
}
void *acpi_get_table(const char *signature, int index) {
int cnt = 0;
struct rsdp *rsdp = acpi_get_rsdp();
if (rsdp == NULL)
return NULL;
bool use_xsdt = false;
if (rsdp->rev >= 2 && rsdp->xsdt_addr)
use_xsdt = true;
struct rsdt *rsdt;
if (use_xsdt)
rsdt = (struct rsdt *)(uintptr_t)rsdp->xsdt_addr;
else
rsdt = (struct rsdt *)(uintptr_t)rsdp->rsdt_addr;
size_t entry_count =
(rsdt->header.length - sizeof(struct sdt)) / (use_xsdt ? 8 : 4);
for (size_t i = 0; i < entry_count; i++) {
struct sdt *ptr;
if (use_xsdt)
ptr = (struct sdt *)(uintptr_t)((uint64_t *)rsdt->ptrs_start)[i];
else
ptr = (struct sdt *)(uintptr_t)((uint32_t *)rsdt->ptrs_start)[i];
if (!memcmp(ptr->signature, signature, 4)
&& !acpi_checksum(ptr, ptr->length)
&& cnt++ == index) {
printv("acpi: Found \"%s\" at %x\n", signature, ptr);
return ptr;
}
}
printv("acpi: \"%s\" not found\n", signature);
return NULL;
}