diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c index bacfc4ea35ac..5559fde1c0fe 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -4,7 +4,8 @@ #include "error.h" #include "../string.h" -#ifdef CONFIG_ACPI +#include +#include /* * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex @@ -29,4 +30,80 @@ static acpi_physical_address get_acpi_rsdp(void) #endif return addr; } -#endif /* CONFIG_ACPI */ + +/* Search EFI system tables for RSDP. */ +static acpi_physical_address efi_get_rsdp_addr(void) +{ + acpi_physical_address rsdp_addr = 0; + +#ifdef CONFIG_EFI + efi_system_table_t *systab; + struct efi_info *ei; + bool efi_64; + int size, i; + char *sig; + + ei = &boot_params->efi_info; + sig = (char *)&ei->efi_loader_signature; + + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { + efi_64 = true; + } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { + efi_64 = false; + } else { + debug_putstr("Wrong EFI loader signature.\n"); + return 0; + } + + /* Get systab from boot params. */ +#ifdef CONFIG_X86_64 + systab = (efi_system_table_t *)(ei->efi_systab | ((__u64)ei->efi_systab_hi<<32)); +#else + if (ei->efi_systab_hi || ei->efi_memmap_hi) { + debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); + return 0; + } + systab = (efi_system_table_t *)ei->efi_systab; +#endif + if (!systab) + error("EFI system table not found."); + + /* + * Get EFI tables from systab. + */ + size = efi_64 ? sizeof(efi_config_table_64_t) : + sizeof(efi_config_table_32_t); + + for (i = 0; i < systab->nr_tables; i++) { + acpi_physical_address table; + void *config_tables; + efi_guid_t guid; + + config_tables = (void *)(systab->tables + size * i); + if (efi_64) { + efi_config_table_64_t *tmp_table; + + tmp_table = config_tables; + guid = tmp_table->guid; + table = tmp_table->table; + + if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { + debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); + return 0; + } + } else { + efi_config_table_32_t *tmp_table; + + tmp_table = config_tables; + guid = tmp_table->guid; + table = tmp_table->table; + } + + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) + rsdp_addr = table; + else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) + return table; + } +#endif + return rsdp_addr; +}