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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "efi-string.h"
#include "efivars.h"
#include "ticks.h"
#include "util.h"
EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, const char16_t *name, const void *buf, size_t size, uint32_t flags) {
assert(vendor);
assert(name);
assert(buf || size == 0);
flags |= EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS;
return RT->SetVariable((char16_t *) name, (EFI_GUID *) vendor, flags, size, (void *) buf);
}
EFI_STATUS efivar_set(const EFI_GUID *vendor, const char16_t *name, const char16_t *value, uint32_t flags) {
assert(vendor);
assert(name);
return efivar_set_raw(vendor, name, value, value ? strsize16(value) : 0, flags);
}
EFI_STATUS efivar_set_uint_string(const EFI_GUID *vendor, const char16_t *name, size_t i, uint32_t flags) {
assert(vendor);
assert(name);
_cleanup_free_ char16_t *str = xasprintf("%zu", i);
return efivar_set(vendor, name, str, flags);
}
EFI_STATUS efivar_set_uint32_le(const EFI_GUID *vendor, const char16_t *name, uint32_t value, uint32_t flags) {
uint8_t buf[4];
assert(vendor);
assert(name);
buf[0] = (uint8_t)(value >> 0U & 0xFF);
buf[1] = (uint8_t)(value >> 8U & 0xFF);
buf[2] = (uint8_t)(value >> 16U & 0xFF);
buf[3] = (uint8_t)(value >> 24U & 0xFF);
return efivar_set_raw(vendor, name, buf, sizeof(buf), flags);
}
EFI_STATUS efivar_set_uint64_le(const EFI_GUID *vendor, const char16_t *name, uint64_t value, uint32_t flags) {
uint8_t buf[8];
assert(vendor);
assert(name);
buf[0] = (uint8_t)(value >> 0U & 0xFF);
buf[1] = (uint8_t)(value >> 8U & 0xFF);
buf[2] = (uint8_t)(value >> 16U & 0xFF);
buf[3] = (uint8_t)(value >> 24U & 0xFF);
buf[4] = (uint8_t)(value >> 32U & 0xFF);
buf[5] = (uint8_t)(value >> 40U & 0xFF);
buf[6] = (uint8_t)(value >> 48U & 0xFF);
buf[7] = (uint8_t)(value >> 56U & 0xFF);
return efivar_set_raw(vendor, name, buf, sizeof(buf), flags);
}
EFI_STATUS efivar_unset(const EFI_GUID *vendor, const char16_t *name, uint32_t flags) {
EFI_STATUS err;
assert(vendor);
assert(name);
/* We could be wiping a non-volatile variable here and the spec makes no guarantees that won't incur
* in an extra write (and thus wear out). So check and clear only if needed. */
err = efivar_get_raw(vendor, name, NULL, NULL);
if (err == EFI_SUCCESS)
return efivar_set_raw(vendor, name, NULL, 0, flags);
return err;
}
EFI_STATUS efivar_get(const EFI_GUID *vendor, const char16_t *name, char16_t **ret) {
_cleanup_free_ char16_t *buf = NULL;
EFI_STATUS err;
char16_t *val;
size_t size;
assert(vendor);
assert(name);
err = efivar_get_raw(vendor, name, (char **) &buf, &size);
if (err != EFI_SUCCESS)
return err;
/* Make sure there are no incomplete characters in the buffer */
if ((size % sizeof(char16_t)) != 0)
return EFI_INVALID_PARAMETER;
if (!ret)
return EFI_SUCCESS;
/* Return buffer directly if it happens to be NUL terminated already */
if (size >= sizeof(char16_t) && buf[size / sizeof(char16_t) - 1] == 0) {
*ret = TAKE_PTR(buf);
return EFI_SUCCESS;
}
/* Make sure a terminating NUL is available at the end */
val = xmalloc(size + sizeof(char16_t));
memcpy(val, buf, size);
val[size / sizeof(char16_t) - 1] = 0; /* NUL terminate */
*ret = val;
return EFI_SUCCESS;
}
EFI_STATUS efivar_get_uint_string(const EFI_GUID *vendor, const char16_t *name, size_t *ret) {
_cleanup_free_ char16_t *val = NULL;
EFI_STATUS err;
uint64_t u;
assert(vendor);
assert(name);
err = efivar_get(vendor, name, &val);
if (err != EFI_SUCCESS)
return err;
if (!parse_number16(val, &u, NULL) || u > SIZE_MAX)
return EFI_INVALID_PARAMETER;
if (ret)
*ret = u;
return EFI_SUCCESS;
}
EFI_STATUS efivar_get_uint32_le(const EFI_GUID *vendor, const char16_t *name, uint32_t *ret) {
_cleanup_free_ char *buf = NULL;
size_t size;
EFI_STATUS err;
assert(vendor);
assert(name);
err = efivar_get_raw(vendor, name, &buf, &size);
if (err != EFI_SUCCESS)
return err;
if (size != sizeof(uint32_t))
return EFI_BUFFER_TOO_SMALL;
if (ret)
*ret = (uint32_t) buf[0] << 0U | (uint32_t) buf[1] << 8U | (uint32_t) buf[2] << 16U |
(uint32_t) buf[3] << 24U;
return EFI_SUCCESS;
}
EFI_STATUS efivar_get_uint64_le(const EFI_GUID *vendor, const char16_t *name, uint64_t *ret) {
_cleanup_free_ char *buf = NULL;
size_t size;
EFI_STATUS err;
assert(vendor);
assert(name);
err = efivar_get_raw(vendor, name, &buf, &size);
if (err != EFI_SUCCESS)
return err;
if (size != sizeof(uint64_t))
return EFI_BUFFER_TOO_SMALL;
if (ret)
*ret = (uint64_t) buf[0] << 0U | (uint64_t) buf[1] << 8U | (uint64_t) buf[2] << 16U |
(uint64_t) buf[3] << 24U | (uint64_t) buf[4] << 32U | (uint64_t) buf[5] << 40U |
(uint64_t) buf[6] << 48U | (uint64_t) buf[7] << 56U;
return EFI_SUCCESS;
}
EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, const char16_t *name, char **ret, size_t *ret_size) {
EFI_STATUS err;
assert(vendor);
assert(name);
size_t size = 0;
err = RT->GetVariable((char16_t *) name, (EFI_GUID *) vendor, NULL, &size, NULL);
if (err != EFI_BUFFER_TOO_SMALL)
return err;
_cleanup_free_ void *buf = xmalloc(size);
err = RT->GetVariable((char16_t *) name, (EFI_GUID *) vendor, NULL, &size, buf);
if (err != EFI_SUCCESS)
return err;
if (ret)
*ret = TAKE_PTR(buf);
if (ret_size)
*ret_size = size;
return EFI_SUCCESS;
}
EFI_STATUS efivar_get_boolean_u8(const EFI_GUID *vendor, const char16_t *name, bool *ret) {
_cleanup_free_ char *b = NULL;
size_t size;
EFI_STATUS err;
assert(vendor);
assert(name);
err = efivar_get_raw(vendor, name, &b, &size);
if (err != EFI_SUCCESS)
return err;
if (ret)
*ret = *b > 0;
return EFI_SUCCESS;
}
void efivar_set_time_usec(const EFI_GUID *vendor, const char16_t *name, uint64_t usec) {
assert(vendor);
assert(name);
if (usec == 0)
usec = time_usec();
if (usec == 0)
return;
_cleanup_free_ char16_t *str = xasprintf("%" PRIu64, usec);
efivar_set(vendor, name, str, 0);
}
uint64_t get_os_indications_supported(void) {
uint64_t osind;
EFI_STATUS err;
/* Returns the supported OS indications. If we can't acquire it, returns a zeroed out mask, i.e. no
* supported features. */
err = efivar_get_uint64_le(MAKE_GUID_PTR(EFI_GLOBAL_VARIABLE), u"OsIndicationsSupported", &osind);
if (err != EFI_SUCCESS)
return 0;
return osind;
}
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