diff options
Diffstat (limited to 'src/shared/efivars.c')
| -rw-r--r-- | src/shared/efivars.c | 237 |
1 files changed, 229 insertions, 8 deletions
diff --git a/src/shared/efivars.c b/src/shared/efivars.c index a319574527..5b3c5f09c8 100644 --- a/src/shared/efivars.c +++ b/src/shared/efivars.c @@ -31,6 +31,40 @@ #ifdef ENABLE_EFI +#define LOAD_OPTION_ACTIVE 0x00000001 +#define MEDIA_DEVICE_PATH 0x04 +#define MEDIA_HARDDRIVE_DP 0x01 +#define MEDIA_FILEPATH_DP 0x04 +#define SIGNATURE_TYPE_GUID 0x02 +#define MBR_TYPE_EFI_PARTITION_TABLE_HEADER 0x02 +#define END_DEVICE_PATH_TYPE 0x7f +#define END_ENTIRE_DEVICE_PATH_SUBTYPE 0xff + +struct boot_option { + uint32_t attr; + uint16_t path_len; + uint16_t title[]; +} __attribute__((packed)); + +struct drive_path { + uint32_t part_nr; + uint64_t part_start; + uint64_t part_size; + char signature[16]; + uint8_t mbr_type; + uint8_t signature_type; +} __attribute__((packed)); + +struct device_path { + uint8_t type; + uint8_t sub_type; + uint16_t length; + union { + uint16_t path[0]; + struct drive_path drive; + }; +} __attribute__((packed)); + bool is_efi_boot(void) { return access("/sys/firmware/efi", F_OK) >= 0; } @@ -128,6 +162,66 @@ int efi_get_variable( return 0; } +int efi_set_variable( + sd_id128_t vendor, + const char *name, + const void *value, + size_t size) { + + struct var { + uint32_t attr; + char buf[]; + } __attribute__((packed)) *buf = NULL; + char *p = NULL; + int fd = -1; + int r; + + assert(name); + + if (asprintf(&p, + "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", + name, SD_ID128_FORMAT_VAL(vendor)) < 0) + return -ENOMEM; + + if (size == 0) { + r = unlink(p); + goto finish; + } + + fd = open(p, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0644); + if (fd < 0) { + r = -errno; + goto finish; + } + + buf = malloc(sizeof(uint32_t) + size); + if (!buf) { + r = -errno; + goto finish; + } + + buf->attr = EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS; + memcpy(buf->buf, value, size); + + r = write(fd, buf, sizeof(uint32_t) + size); + if (r < 0) { + r = -errno; + goto finish; + } + + if ((size_t)r != sizeof(uint32_t) + size) { + r = -EIO; + goto finish; + } + +finish: + if (fd >= 0) + close(fd); + free(buf); + free(p); + return r; +} + int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) { _cleanup_free_ void *s = NULL; size_t ss = 0; @@ -179,8 +273,8 @@ int efi_get_boot_option( uint16_t id, char **title, sd_id128_t *part_uuid, - char **path) { - + char **path, + bool *active) { struct boot_option { uint32_t attr; uint16_t path_len; @@ -250,23 +344,23 @@ int efi_get_boot_option( break; /* Type 0x7F – End of Hardware Device Path, Sub-Type 0xFF – End Entire Device Path */ - if (dpath->type == 0x7f && dpath->sub_type == 0xff) + if (dpath->type == END_DEVICE_PATH_TYPE && dpath->sub_type == END_ENTIRE_DEVICE_PATH_SUBTYPE) break; dnext += dpath->length; /* Type 0x04 – Media Device Path */ - if (dpath->type != 0x04) + if (dpath->type != MEDIA_DEVICE_PATH) continue; /* Sub-Type 1 – Hard Drive */ - if (dpath->sub_type == 0x01) { + if (dpath->sub_type == MEDIA_HARDDRIVE_DP) { /* 0x02 – GUID Partition Table */ - if (dpath->drive.mbr_type != 0x02) + if (dpath->drive.mbr_type != MBR_TYPE_EFI_PARTITION_TABLE_HEADER) continue; /* 0x02 – GUID signature */ - if (dpath->drive.signature_type != 0x02) + if (dpath->drive.signature_type != SIGNATURE_TYPE_GUID) continue; if (part_uuid) @@ -275,8 +369,9 @@ int efi_get_boot_option( } /* Sub-Type 4 – File Path */ - if (dpath->sub_type == 0x04 && !p && path) { + if (dpath->sub_type == MEDIA_FILEPATH_DP && !p && path) { p = utf16_to_utf8(dpath->path, dpath->length-4); + efi_tilt_backslashes(p); continue; } } @@ -288,6 +383,8 @@ int efi_get_boot_option( *part_uuid = p_uuid; if (path) *path = p; + if (active) + *active = !!header->attr & LOAD_OPTION_ACTIVE; return 0; err: @@ -296,6 +393,126 @@ err: return err; } +static void to_utf16(uint16_t *dest, const char *src) { + int i; + + for (i = 0; src[i] != '\0'; i++) + dest[i] = src[i]; + dest[i] = '\0'; +} + +struct guid { + uint32_t u1; + uint16_t u2; + uint16_t u3; + uint8_t u4[8]; +} __attribute__((packed)); + +static void id128_to_efi_guid(sd_id128_t id, void *guid) { + struct guid *uuid = guid; + + uuid->u1 = id.bytes[0] << 24 | id.bytes[1] << 16 | id.bytes[2] << 8 | id.bytes[3]; + uuid->u2 = id.bytes[4] << 8 | id.bytes[5]; + uuid->u3 = id.bytes[6] << 8 | id.bytes[7]; + memcpy(uuid->u4, id.bytes+8, sizeof(uuid->u4)); +} + +static uint16_t *tilt_slashes(uint16_t *s) { + uint16_t *p; + + for (p = s; *p; p++) + if (*p == '/') + *p = '\\'; + + return s; +} + +char *efi_tilt_backslashes(char *s) { + char *p; + + for (p = s; *p; p++) + if (*p == '\\') + *p = '/'; + + return s; +} + +int efi_add_boot_option(uint16_t id, const char *title, + uint32_t part, uint64_t pstart, uint64_t psize, + sd_id128_t part_uuid, const char *path) { + char boot_id[9]; + char *buf; + size_t size; + size_t title_len; + size_t path_len; + struct boot_option *option; + struct device_path *devicep; + int err; + + title_len = (strlen(title)+1) * 2; + path_len = (strlen(path)+1) * 2; + + buf = calloc(sizeof(struct boot_option) + title_len + + sizeof(struct drive_path) + + sizeof(struct device_path) + path_len, 1); + if (!buf) { + err = -ENOMEM; + goto finish; + } + + /* header */ + option = (struct boot_option *)buf; + option->attr = LOAD_OPTION_ACTIVE; + option->path_len = offsetof(struct device_path, drive) + sizeof(struct drive_path) + + offsetof(struct device_path, path) + path_len + + offsetof(struct device_path, path); + to_utf16(option->title, title); + size = offsetof(struct boot_option, title) + title_len; + + /* partition info */ + devicep = (struct device_path *)(buf + size); + devicep->type = MEDIA_DEVICE_PATH; + devicep->sub_type = MEDIA_HARDDRIVE_DP; + devicep->length = offsetof(struct device_path, drive) + sizeof(struct drive_path); + devicep->drive.part_nr = part; + devicep->drive.part_start = pstart; + devicep->drive.part_size = psize; + devicep->drive.signature_type = SIGNATURE_TYPE_GUID; + devicep->drive.mbr_type = MBR_TYPE_EFI_PARTITION_TABLE_HEADER; + id128_to_efi_guid(part_uuid, devicep->drive.signature); + size += devicep->length; + + /* path to loader */ + devicep = (struct device_path *)(buf + size); + devicep->type = MEDIA_DEVICE_PATH; + devicep->sub_type = MEDIA_FILEPATH_DP; + devicep->length = offsetof(struct device_path, path) + path_len; + to_utf16(devicep->path, path); + tilt_slashes(devicep->path); + size += devicep->length; + + /* end of path */ + devicep = (struct device_path *)(buf + size); + devicep->type = END_DEVICE_PATH_TYPE; + devicep->sub_type = END_ENTIRE_DEVICE_PATH_SUBTYPE; + devicep->length = offsetof(struct device_path, path); + size += devicep->length; + + snprintf(boot_id, sizeof(boot_id), "Boot%04X", id); + err = efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, buf, size); + +finish: + free(buf); + return err; +} + +int efi_remove_boot_option(uint16_t id) { + char boot_id[9]; + + snprintf(boot_id, sizeof(boot_id), "Boot%04X", id); + return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, 0); +} + int efi_get_boot_order(uint16_t **order) { void *buf; size_t l; @@ -320,6 +537,10 @@ int efi_get_boot_order(uint16_t **order) { return (int) (l / sizeof(uint16_t)); } +int efi_set_boot_order(uint16_t *order, size_t n) { + return efi_set_variable(EFI_VENDOR_GLOBAL, "BootOrder", order, n * sizeof(uint16_t)); +} + static int boot_id_hex(const char s[4]) { int i; int id = 0; |