From: khaalid <khaliidca...@gmail.com>
This command is intended to print or dump all UEFI runtime services.
The structure will look like efivar tool, since visually most people are
familiar with it. If the variable content is string then dump it as
string, otherwise for non string variables print them as raw hex; just
the way efivar command does.
Signed-off-by: khaalid <khaliidca...@gmail.com>
---
grub-core/Makefile.core.def | 6 ++
grub-core/commands/efi/efivar.c | 150 ++++++++++++++++++++++++++++++++
2 files changed, 156 insertions(+)
create mode 100644 grub-core/commands/efi/efivar.c
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index f70e02e69..ef3dc2dd0 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -840,6 +840,12 @@ module = {
enable = efi;
};
+module = {
+ name = efivar;
+ efi = commands/efi/efivar.c;
+ enable = efi;
+};
+
module = {
name = blocklist;
common = commands/blocklist.c;
diff --git a/grub-core/commands/efi/efivar.c b/grub-core/commands/efi/efivar.c
new file mode 100644
index 000000000..8d81e01ab
--- /dev/null
+++ b/grub-core/commands/efi/efivar.c
@@ -0,0 +1,150 @@
+/* efivar.c - dump runtime uefi variables. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2009 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+
+#include <grub/dl.h>
+#include <grub/misc.h>
+#include <grub/command.h>
+#include <grub/charset.h>
+#include <grub/efi/efi.h>
+#include <grub/efi/api.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+
+/* Check if the data looks like UTF-16LE text */
+static inline int
+is_likely_utf16_string(grub_uint8_t *data, grub_size_t len)
+{
+ if (len < 4) return 0;
+ for (grub_size_t i = 0; i < len; i += 2) {
+ if (data[i] == 0 && data[i+1] == 0) return 1; // Null terminator in
UTF-16
+ if (data[i+1] != 0 && data[i+1] != 0x20) return 0; // High byte must
be 0 or space-like
+ }
+ return 1;
+}
+
+static void
+get_variable_data(const char *variable_name, grub_guid_t *variable_guid)
+{
+ grub_efi_status_t status;
+ grub_efi_uint32_t attributes;
+ grub_size_t data_size;
+ grub_uint8_t *data;
+
+ status = grub_efi_get_variable_with_attributes(variable_name,
variable_guid,
+ &data_size, (void **)&data,
&attributes);
+ if (status != GRUB_EFI_SUCCESS)
+ {
+ grub_error(GRUB_ERR_BAD_MODULE, "Failed to retrieve variable data 0x%"
PRIxGRUB_EFI_UINTN_T, status);
+ return;
+ }
+
+ grub_printf("Attributes:\n");
+ if (attributes & GRUB_EFI_VARIABLE_NON_VOLATILE)
+ grub_printf("\tNon-Volatile\n");
+ if (attributes & GRUB_EFI_VARIABLE_BOOTSERVICE_ACCESS)
+ grub_printf("\tBoot Service Access\n");
+ if (attributes & GRUB_EFI_VARIABLE_RUNTIME_ACCESS)
+ grub_printf("\tRuntime Service Access\n");
+
+ if (is_likely_utf16_string(data, data_size))
+ {
+ grub_printf("Value (as UTF-16 string):\n");
+ for (grub_size_t i = 0; i + 1 < data_size; i += 2)
+ {
+ grub_uint16_t ch = data[i] | (data[i+1] << 8);
+ if (ch == 0) break;
+ grub_printf("%c", (char)ch); // crude but works if high byte
is zero
+ }
+ grub_printf("\n");
+ }
+ else
+ {
+ grub_printf("Value (hex):\n");
+ for (grub_size_t i = 0; i < data_size; i++)
+ {
+ grub_printf("%02x ", data[i]);
+ if ((i + 1) % 16 == 0)
+ grub_printf("\n");
+ }
+ grub_printf("\n");
+ }
+
+ grub_free(data);
+}
+
+static grub_err_t
+dump_efi_variables(void)
+{
+ grub_efi_status_t status;
+ grub_efi_runtime_services_t *r;
+ grub_efi_uintn_t variable_name_size = 512;
+ grub_efi_char16_t *variable_name;
+ grub_uint8_t *variable_name_string = NULL;
+ grub_guid_t vendor_guid;
+
+ r = grub_efi_system_table->runtime_services;
+
+ variable_name = grub_malloc(variable_name_size);
+ if (!variable_name)
+ return grub_error(GRUB_ERR_OUT_OF_MEMORY, "initial malloc
failed");
+ *variable_name = 0; /* Start with empty string */
+
+ while (1)
+ {
+ status = r->get_next_variable_name(&variable_name_size,
variable_name, &vendor_guid);
+ if (status == GRUB_EFI_NOT_FOUND)
+ break;
+ variable_name_string = grub_realloc(variable_name_string,
variable_name_size);
+ grub_utf16_to_utf8(variable_name_string, variable_name,
variable_name_size);
+
grub_printf("%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x-%s\n",
vendor_guid.data1,
+
vendor_guid.data2,
+
vendor_guid.data3,
+
vendor_guid.data4[0], vendor_guid.data4[1],
+
vendor_guid.data4[2], vendor_guid.data4[3],
+
vendor_guid.data4[4], vendor_guid.data4[5],
+
vendor_guid.data4[6], vendor_guid.data4[7],
+
variable_name_string);
+ get_variable_data((char*)variable_name_string, &vendor_guid);
+ }
+
+ grub_free(variable_name);
+ grub_free(variable_name_string);
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_cmd_efivar (grub_command_t cmd __attribute__((unused)),
+ int argc __attribute__((unused)), char **argv
__attribute__((unused)))
+{
+ return dump_efi_variables();
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(efivar)
+{
+ cmd = grub_register_command("efivar", grub_cmd_efivar, NULL,
N_("Display UEFI variables."));
+}
+GRUB_MOD_FINI(efivar)
+{
+ grub_unregister_command(cmd);
+}
--
2.49.0
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