2 * EFI Variables - efivars.c
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
33 * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
34 * converted driver to export variable information via sysfs
35 * and moved to drivers/firmware directory
36 * bumped revision number to v0.07 to reflect conversion & move
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
44 * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
45 * use list_for_each_safe when deleting vars.
46 * remove ifdef CONFIG_SMP around include <linux/smp.h>
47 * v0.04 release to linux-ia64@linuxia64.org
49 * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
50 * Moved vars from /proc/efi to /proc/efi/vars, and made
51 * efi.c own the /proc/efi directory.
52 * v0.03 release to linux-ia64@linuxia64.org
54 * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
55 * At the request of Stephane, moved ownership of /proc/efi
56 * to efi.c, and now efivars lives under /proc/efi/vars.
58 * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
59 * Feedback received from Stephane Eranian incorporated.
60 * efivar_write() checks copy_from_user() return value.
61 * efivar_read/write() returns proper errno.
62 * v0.02 release to linux-ia64@linuxia64.org
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
68 #include <linux/capability.h>
69 #include <linux/types.h>
70 #include <linux/errno.h>
71 #include <linux/init.h>
73 #include <linux/module.h>
74 #include <linux/string.h>
75 #include <linux/smp.h>
76 #include <linux/efi.h>
77 #include <linux/sysfs.h>
78 #include <linux/kobject.h>
79 #include <linux/device.h>
80 #include <linux/slab.h>
82 #include <asm/uaccess.h>
84 #define EFIVARS_VERSION "0.08"
85 #define EFIVARS_DATE "2004-May-17"
87 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
88 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
89 MODULE_LICENSE("GPL");
90 MODULE_VERSION(EFIVARS_VERSION);
93 * The maximum size of VariableName + Data = 1024
94 * Therefore, it's reasonable to save that much
95 * space in each part of the structure,
96 * and we use a page for reading/writing.
100 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
101 efi_guid_t VendorGuid;
102 unsigned long DataSize;
106 } __attribute__((packed));
109 struct efivar_entry {
110 struct efivars *efivars;
111 struct efi_variable var;
112 struct list_head list;
116 struct efivar_attribute {
117 struct attribute attr;
118 ssize_t (*show) (struct efivar_entry *entry, char *buf);
119 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
123 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
124 struct efivar_attribute efivar_attr_##_name = { \
125 .attr = {.name = __stringify(_name), .mode = _mode}, \
130 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
131 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
134 * Prototype for sysfs creation function
137 efivar_create_sysfs_entry(struct efivars *efivars,
138 unsigned long variable_name_size,
139 efi_char16_t *variable_name,
140 efi_guid_t *vendor_guid);
142 /* Return the number of unicode characters in data */
144 utf16_strnlen(efi_char16_t *s, size_t maxlength)
146 unsigned long length = 0;
148 while (*s++ != 0 && length < maxlength)
153 static inline unsigned long
154 utf16_strlen(efi_char16_t *s)
156 return utf16_strnlen(s, ~0UL);
160 * Return the number of bytes is the length of this string
161 * Note: this is NOT the same as the number of unicode characters
163 static inline unsigned long
164 utf16_strsize(efi_char16_t *data, unsigned long maxlength)
166 return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
170 validate_device_path(struct efi_variable *var, int match, u8 *buffer,
173 struct efi_generic_dev_path *node;
176 node = (struct efi_generic_dev_path *)buffer;
178 if (len < sizeof(*node))
181 while (offset <= len - sizeof(*node) &&
182 node->length >= sizeof(*node) &&
183 node->length <= len - offset) {
184 offset += node->length;
186 if ((node->type == EFI_DEV_END_PATH ||
187 node->type == EFI_DEV_END_PATH2) &&
188 node->sub_type == EFI_DEV_END_ENTIRE)
191 node = (struct efi_generic_dev_path *)(buffer + offset);
195 * If we're here then either node->length pointed past the end
196 * of the buffer or we reached the end of the buffer without
197 * finding a device path end node.
203 validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
206 /* An array of 16-bit integers */
214 validate_load_option(struct efi_variable *var, int match, u8 *buffer,
218 int i, desclength = 0, namelen;
220 namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
222 /* Either "Boot" or "Driver" followed by four digits of hex */
223 for (i = match; i < match+4; i++) {
224 if (var->VariableName[i] > 127 ||
225 hex_to_bin(var->VariableName[i] & 0xff) < 0)
229 /* Reject it if there's 4 digits of hex and then further content */
230 if (namelen > match + 4)
233 /* A valid entry must be at least 8 bytes */
237 filepathlength = buffer[4] | buffer[5] << 8;
240 * There's no stored length for the description, so it has to be
243 desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
245 /* Each boot entry must have a descriptor */
250 * If the sum of the length of the description, the claimed filepath
251 * length and the original header are greater than the length of the
252 * variable, it's malformed
254 if ((desclength + filepathlength + 6) > len)
258 * And, finally, check the filepath
260 return validate_device_path(var, match, buffer + desclength + 6,
265 validate_uint16(struct efi_variable *var, int match, u8 *buffer,
268 /* A single 16-bit integer */
276 validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
281 for (i = 0; i < len; i++) {
292 struct variable_validate {
294 bool (*validate)(struct efi_variable *var, int match, u8 *data,
298 static const struct variable_validate variable_validate[] = {
299 { "BootNext", validate_uint16 },
300 { "BootOrder", validate_boot_order },
301 { "DriverOrder", validate_boot_order },
302 { "Boot*", validate_load_option },
303 { "Driver*", validate_load_option },
304 { "ConIn", validate_device_path },
305 { "ConInDev", validate_device_path },
306 { "ConOut", validate_device_path },
307 { "ConOutDev", validate_device_path },
308 { "ErrOut", validate_device_path },
309 { "ErrOutDev", validate_device_path },
310 { "Timeout", validate_uint16 },
311 { "Lang", validate_ascii_string },
312 { "PlatformLang", validate_ascii_string },
317 validate_var(struct efi_variable *var, u8 *data, unsigned long len)
320 u16 *unicode_name = var->VariableName;
322 for (i = 0; variable_validate[i].validate != NULL; i++) {
323 const char *name = variable_validate[i].name;
326 for (match = 0; ; match++) {
327 char c = name[match];
328 u16 u = unicode_name[match];
330 /* All special variables are plain ascii */
334 /* Wildcard in the matching name means we've matched */
336 return variable_validate[i].validate(var,
339 /* Case sensitive match */
343 /* Reached the end of the string while matching */
345 return variable_validate[i].validate(var,
354 get_var_data(struct efivars *efivars, struct efi_variable *var)
358 spin_lock(&efivars->lock);
359 var->DataSize = 1024;
360 status = efivars->ops->get_variable(var->VariableName,
365 spin_unlock(&efivars->lock);
366 if (status != EFI_SUCCESS) {
367 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
374 efivar_guid_read(struct efivar_entry *entry, char *buf)
376 struct efi_variable *var = &entry->var;
382 efi_guid_unparse(&var->VendorGuid, str);
384 str += sprintf(str, "\n");
390 efivar_attr_read(struct efivar_entry *entry, char *buf)
392 struct efi_variable *var = &entry->var;
399 status = get_var_data(entry->efivars, var);
400 if (status != EFI_SUCCESS)
403 if (var->Attributes & 0x1)
404 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
405 if (var->Attributes & 0x2)
406 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
407 if (var->Attributes & 0x4)
408 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
413 efivar_size_read(struct efivar_entry *entry, char *buf)
415 struct efi_variable *var = &entry->var;
422 status = get_var_data(entry->efivars, var);
423 if (status != EFI_SUCCESS)
426 str += sprintf(str, "0x%lx\n", var->DataSize);
431 efivar_data_read(struct efivar_entry *entry, char *buf)
433 struct efi_variable *var = &entry->var;
439 status = get_var_data(entry->efivars, var);
440 if (status != EFI_SUCCESS)
443 memcpy(buf, var->Data, var->DataSize);
444 return var->DataSize;
447 * We allow each variable to be edited via rewriting the
448 * entire efi variable structure.
451 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
453 struct efi_variable *new_var, *var = &entry->var;
454 struct efivars *efivars = entry->efivars;
455 efi_status_t status = EFI_NOT_FOUND;
457 if (count != sizeof(struct efi_variable))
460 new_var = (struct efi_variable *)buf;
462 * If only updating the variable data, then the name
463 * and guid should remain the same
465 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
466 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
467 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
471 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
472 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
476 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
477 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
478 printk(KERN_ERR "efivars: Malformed variable content\n");
482 spin_lock(&efivars->lock);
483 status = efivars->ops->set_variable(new_var->VariableName,
484 &new_var->VendorGuid,
489 spin_unlock(&efivars->lock);
491 if (status != EFI_SUCCESS) {
492 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
497 memcpy(&entry->var, new_var, count);
502 efivar_show_raw(struct efivar_entry *entry, char *buf)
504 struct efi_variable *var = &entry->var;
510 status = get_var_data(entry->efivars, var);
511 if (status != EFI_SUCCESS)
514 memcpy(buf, var, sizeof(*var));
519 * Generic read/write functions that call the specific functions of
522 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
525 struct efivar_entry *var = to_efivar_entry(kobj);
526 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
529 if (!capable(CAP_SYS_ADMIN))
532 if (efivar_attr->show) {
533 ret = efivar_attr->show(var, buf);
538 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
539 const char *buf, size_t count)
541 struct efivar_entry *var = to_efivar_entry(kobj);
542 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
545 if (!capable(CAP_SYS_ADMIN))
548 if (efivar_attr->store)
549 ret = efivar_attr->store(var, buf, count);
554 static const struct sysfs_ops efivar_attr_ops = {
555 .show = efivar_attr_show,
556 .store = efivar_attr_store,
559 static void efivar_release(struct kobject *kobj)
561 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
565 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
566 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
567 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
568 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
569 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
571 static struct attribute *def_attrs[] = {
572 &efivar_attr_guid.attr,
573 &efivar_attr_size.attr,
574 &efivar_attr_attributes.attr,
575 &efivar_attr_data.attr,
576 &efivar_attr_raw_var.attr,
580 static struct kobj_type efivar_ktype = {
581 .release = efivar_release,
582 .sysfs_ops = &efivar_attr_ops,
583 .default_attrs = def_attrs,
587 efivar_unregister(struct efivar_entry *var)
589 kobject_put(&var->kobj);
593 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
594 struct bin_attribute *bin_attr,
595 char *buf, loff_t pos, size_t count)
597 struct efi_variable *new_var = (struct efi_variable *)buf;
598 struct efivars *efivars = bin_attr->private;
599 struct efivar_entry *search_efivar, *n;
600 unsigned long strsize1, strsize2;
601 efi_status_t status = EFI_NOT_FOUND;
604 if (!capable(CAP_SYS_ADMIN))
607 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
608 validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
609 printk(KERN_ERR "efivars: Malformed variable content\n");
613 spin_lock(&efivars->lock);
616 * Does this variable already exist?
618 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
619 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
620 strsize2 = utf16_strsize(new_var->VariableName, 1024);
621 if (strsize1 == strsize2 &&
622 !memcmp(&(search_efivar->var.VariableName),
623 new_var->VariableName, strsize1) &&
624 !efi_guidcmp(search_efivar->var.VendorGuid,
625 new_var->VendorGuid)) {
631 spin_unlock(&efivars->lock);
635 /* now *really* create the variable via EFI */
636 status = efivars->ops->set_variable(new_var->VariableName,
637 &new_var->VendorGuid,
642 if (status != EFI_SUCCESS) {
643 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
645 spin_unlock(&efivars->lock);
648 spin_unlock(&efivars->lock);
650 /* Create the entry in sysfs. Locking is not required here */
651 status = efivar_create_sysfs_entry(efivars,
652 utf16_strsize(new_var->VariableName,
654 new_var->VariableName,
655 &new_var->VendorGuid);
657 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
662 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
663 struct bin_attribute *bin_attr,
664 char *buf, loff_t pos, size_t count)
666 struct efi_variable *del_var = (struct efi_variable *)buf;
667 struct efivars *efivars = bin_attr->private;
668 struct efivar_entry *search_efivar, *n;
669 unsigned long strsize1, strsize2;
670 efi_status_t status = EFI_NOT_FOUND;
673 if (!capable(CAP_SYS_ADMIN))
676 spin_lock(&efivars->lock);
679 * Does this variable already exist?
681 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
682 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
683 strsize2 = utf16_strsize(del_var->VariableName, 1024);
684 if (strsize1 == strsize2 &&
685 !memcmp(&(search_efivar->var.VariableName),
686 del_var->VariableName, strsize1) &&
687 !efi_guidcmp(search_efivar->var.VendorGuid,
688 del_var->VendorGuid)) {
694 spin_unlock(&efivars->lock);
697 /* force the Attributes/DataSize to 0 to ensure deletion */
698 del_var->Attributes = 0;
699 del_var->DataSize = 0;
701 status = efivars->ops->set_variable(del_var->VariableName,
702 &del_var->VendorGuid,
707 if (status != EFI_SUCCESS) {
708 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
710 spin_unlock(&efivars->lock);
713 list_del(&search_efivar->list);
714 /* We need to release this lock before unregistering. */
715 spin_unlock(&efivars->lock);
716 efivar_unregister(search_efivar);
718 /* It's dead Jim.... */
723 * Let's not leave out systab information that snuck into
726 static ssize_t systab_show(struct kobject *kobj,
727 struct kobj_attribute *attr, char *buf)
734 if (efi.mps != EFI_INVALID_TABLE_ADDR)
735 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
736 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
737 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
738 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
739 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
740 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
741 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
742 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
743 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
744 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
745 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
746 if (efi.uga != EFI_INVALID_TABLE_ADDR)
747 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
752 static struct kobj_attribute efi_attr_systab =
753 __ATTR(systab, 0400, systab_show, NULL);
755 static struct attribute *efi_subsys_attrs[] = {
756 &efi_attr_systab.attr,
757 NULL, /* maybe more in the future? */
760 static struct attribute_group efi_subsys_attr_group = {
761 .attrs = efi_subsys_attrs,
764 static struct kobject *efi_kobj;
767 * efivar_create_sysfs_entry()
769 * variable_name_size = number of bytes required to hold
770 * variable_name (not counting the NULL
771 * character at the end.
772 * efivars->lock is not held on entry or exit.
773 * Returns 1 on failure, 0 on success
776 efivar_create_sysfs_entry(struct efivars *efivars,
777 unsigned long variable_name_size,
778 efi_char16_t *variable_name,
779 efi_guid_t *vendor_guid)
781 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
783 struct efivar_entry *new_efivar;
785 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
786 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
788 if (!short_name || !new_efivar) {
794 new_efivar->efivars = efivars;
795 memcpy(new_efivar->var.VariableName, variable_name,
797 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
799 /* Convert Unicode to normal chars (assume top bits are 0),
801 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
802 short_name[i] = variable_name[i] & 0xFF;
804 /* This is ugly, but necessary to separate one vendor's
805 private variables from another's. */
807 *(short_name + strlen(short_name)) = '-';
808 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
810 new_efivar->kobj.kset = efivars->kset;
811 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
819 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
823 spin_lock(&efivars->lock);
824 list_add(&new_efivar->list, &efivars->list);
825 spin_unlock(&efivars->lock);
831 create_efivars_bin_attributes(struct efivars *efivars)
833 struct bin_attribute *attr;
837 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
841 attr->attr.name = "new_var";
842 attr->attr.mode = 0200;
843 attr->write = efivar_create;
844 attr->private = efivars;
845 efivars->new_var = attr;
848 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
853 attr->attr.name = "del_var";
854 attr->attr.mode = 0200;
855 attr->write = efivar_delete;
856 attr->private = efivars;
857 efivars->del_var = attr;
859 sysfs_bin_attr_init(efivars->new_var);
860 sysfs_bin_attr_init(efivars->del_var);
863 error = sysfs_create_bin_file(&efivars->kset->kobj,
866 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
867 " due to error %d\n", error);
870 error = sysfs_create_bin_file(&efivars->kset->kobj,
873 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
874 " due to error %d\n", error);
875 sysfs_remove_bin_file(&efivars->kset->kobj,
882 kfree(efivars->del_var);
883 efivars->del_var = NULL;
884 kfree(efivars->new_var);
885 efivars->new_var = NULL;
889 void unregister_efivars(struct efivars *efivars)
891 struct efivar_entry *entry, *n;
893 list_for_each_entry_safe(entry, n, &efivars->list, list) {
894 spin_lock(&efivars->lock);
895 list_del(&entry->list);
896 spin_unlock(&efivars->lock);
897 efivar_unregister(entry);
899 if (efivars->new_var)
900 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
901 if (efivars->del_var)
902 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
903 kfree(efivars->new_var);
904 kfree(efivars->del_var);
905 kset_unregister(efivars->kset);
907 EXPORT_SYMBOL_GPL(unregister_efivars);
909 int register_efivars(struct efivars *efivars,
910 const struct efivar_operations *ops,
911 struct kobject *parent_kobj)
913 efi_status_t status = EFI_NOT_FOUND;
914 efi_guid_t vendor_guid;
915 efi_char16_t *variable_name;
916 unsigned long variable_name_size = 1024;
919 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
920 if (!variable_name) {
921 printk(KERN_ERR "efivars: Memory allocation failed.\n");
925 spin_lock_init(&efivars->lock);
926 INIT_LIST_HEAD(&efivars->list);
929 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
930 if (!efivars->kset) {
931 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
937 * Per EFI spec, the maximum storage allocated for both
938 * the variable name and variable data is 1024 bytes.
942 variable_name_size = 1024;
944 status = ops->get_next_variable(&variable_name_size,
949 efivar_create_sysfs_entry(efivars,
957 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
959 status = EFI_NOT_FOUND;
962 } while (status != EFI_NOT_FOUND);
964 error = create_efivars_bin_attributes(efivars);
966 unregister_efivars(efivars);
969 kfree(variable_name);
973 EXPORT_SYMBOL_GPL(register_efivars);
975 static struct efivars __efivars;
976 static struct efivar_operations ops;
979 * For now we register the efi subsystem with the firmware subsystem
980 * and the vars subsystem with the efi subsystem. In the future, it
981 * might make sense to split off the efi subsystem into its own
982 * driver, but for now only efivars will register with it, so just
991 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
997 /* For now we'll register the efi directory at /sys/firmware/efi */
998 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
1000 printk(KERN_ERR "efivars: Firmware registration failed.\n");
1004 ops.get_variable = efi.get_variable;
1005 ops.set_variable = efi.set_variable;
1006 ops.get_next_variable = efi.get_next_variable;
1007 error = register_efivars(&__efivars, &ops, efi_kobj);
1011 /* Don't forget the systab entry */
1012 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
1015 "efivars: Sysfs attribute export failed with error %d.\n",
1017 goto err_unregister;
1023 unregister_efivars(&__efivars);
1025 kobject_put(efi_kobj);
1033 unregister_efivars(&__efivars);
1034 kobject_put(efi_kobj);
1038 module_init(efivars_init);
1039 module_exit(efivars_exit);