diff options
Diffstat (limited to 'src/shared/efivars.c')
| -rw-r--r-- | src/shared/efivars.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/shared/efivars.c b/src/shared/efivars.c index 20067c601a..b82f74a459 100644 --- a/src/shared/efivars.c +++ b/src/shared/efivars.c @@ -25,6 +25,7 @@ #include "util.h" #include "utf8.h" +#include "virt.h" #include "efivars.h" #ifdef ENABLE_EFI @@ -37,6 +38,7 @@ #define MBR_TYPE_EFI_PARTITION_TABLE_HEADER 0x02 #define END_DEVICE_PATH_TYPE 0x7f #define END_ENTIRE_DEVICE_PATH_SUBTYPE 0xff +#define EFI_OS_INDICATIONS_BOOT_TO_FW_UI 0x0000000000000001 struct boot_option { uint32_t attr; @@ -93,6 +95,76 @@ int is_efi_secure_boot_setup_mode(void) { return read_flag("SetupMode"); } +int efi_reboot_to_firmware_supported(void) { + int r; + size_t s; + uint64_t b; + _cleanup_free_ void *v = NULL; + + if (!is_efi_boot() || detect_container(NULL) > 0) + return -EOPNOTSUPP; + + r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndicationsSupported", NULL, &v, &s); + if (r < 0) + return r; + else if (s != sizeof(uint64_t)) + return -EINVAL; + + b = *(uint64_t *)v; + b &= EFI_OS_INDICATIONS_BOOT_TO_FW_UI; + return b > 0 ? 0 : -EOPNOTSUPP; +} + +static int get_os_indications(uint64_t *os_indication) { + int r; + size_t s; + _cleanup_free_ void *v = NULL; + + r = efi_reboot_to_firmware_supported(); + if (r < 0) + return r; + + r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndications", NULL, &v, &s); + if (r < 0) + return r; + else if (s != sizeof(uint64_t)) + return -EINVAL; + + *os_indication = *(uint64_t *)v; + return 0; +} + +int efi_get_reboot_to_firmware(void) { + int r; + uint64_t b; + + r = get_os_indications(&b); + if (r < 0) + return r; + + return !!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI); +} + +int efi_set_reboot_to_firmware(bool value) { + int r; + uint64_t b, b_new; + + r = get_os_indications(&b); + if (r < 0) + return r; + + if (value) + b_new = b | EFI_OS_INDICATIONS_BOOT_TO_FW_UI; + else + b_new = b & ~EFI_OS_INDICATIONS_BOOT_TO_FW_UI; + + /* Avoid writing to efi vars store if we can due to firmware bugs. */ + if (b != b_new) + return efi_set_variable(EFI_VENDOR_GLOBAL, "OsIndications", &b_new, sizeof(uint64_t)); + + return 0; +} + int efi_get_variable( sd_id128_t vendor, const char *name, |