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Diffstat (limited to 'src/shared/efivars.c')
-rw-r--r--src/shared/efivars.c237
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;