From: khaalid <khaliidc...@gmail.com>
I followed the suggestion and implemented the option parsing using extcmd.
However, I feel this command is not ideal to have any arguments. Similar
commands like
lsefi, lsefimmap, and lsefisystab don’t take arguments—they simply dump data.
Since this command also just dumps variables and doesn’t do anything more,
adding options might introduce inconsistency.
Returning grub_err_t for `dump_variable_data` isn't ideal neither for
two reasons:
- First the only place the function fail is if
`grub_efi_get_variable_with_attributes`
fail; this function returns EFI_STATUS mostly, so even if it fails and sets
errno then
`grub_error` already overrided it so we get GRUB_ERR_IO always.
- Second `dump_variable_data` is expected to fail because not every
variable can neccessarily retrieved, some will fail due security
restrictions. So it is better
if we skip failed variables and move on to the next one.
Let me know what do you think.
Signed-off-by: Khalid Ali <khaliidca...@gmail.com>
---
grub-core/Makefile.core.def | 6 ++
grub-core/commands/efi/lsefivar.c | 133 ++++++++++++++++++++++++++++++
2 files changed, 139 insertions(+)
create mode 100644 grub-core/commands/efi/lsefivar.c
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index f70e02e69..8b9cf2a68 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -840,6 +840,12 @@ module = {
enable = efi;
};
+module = {
+ name = lsefivar;
+ efi = commands/efi/lsefivar.c;
+ enable = efi;
+};
+
module = {
name = blocklist;
common = commands/blocklist.c;
diff --git a/grub-core/commands/efi/lsefivar.c
b/grub-core/commands/efi/lsefivar.c
new file mode 100644
index 000000000..06bf8d505
--- /dev/null
+++ b/grub-core/commands/efi/lsefivar.c
@@ -0,0 +1,133 @@
+/* efivar.c - dump runtime uefi variables. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2025 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/charset.h>
+#include <grub/extcmd.h>
+#include <grub/efi/efi.h>
+#include <grub/efi/api.h>
+#include <grub/lib/hexdump.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static const struct grub_arg_option options[] =
+{
+ {0, 'l', 0, N_("Dump variable contents"), 0, 0},
+ {0, 0, 0, 0, 0, 0}
+};
+
+static void
+dump_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;
+ void *data;
+
+ status = grub_efi_get_variable_with_attributes(variable_name,
variable_guid,
+ &data_size, &data,
&attributes);
+ if (status != GRUB_EFI_SUCCESS)
+ {
+ grub_error(GRUB_ERR_IO, "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"));
+
+ grub_printf(_("Value:\n"));
+ hexdump(0, data, data_size);
+ 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_calloc(variable_name_size,
sizeof(grub_efi_char16_t));
+ if (variable_name == NULL)
+ return grub_errno;
+ *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;
+ else if (status == GRUB_EFI_BUFFER_TOO_SMALL)
+ {
+ grub_dprintf("lsefivar", "buffer isn't enough,
enlarging up to %ld bytes\n",variable_name_size * sizeof(grub_efi_char16_t));
+ variable_name = grub_realloc(variable_name,
variable_name_size * sizeof(grub_efi_char16_t));
+ if (variable_name == NULL)
+ return grub_errno;
+ }
+ variable_name_string = grub_calloc(variable_name_size + 1,
GRUB_MAX_UTF8_PER_UTF16);
+ if (variable_name_string == NULL)
+ {
+ grub_free(variable_name);
+ return grub_errno;
+ }
+ *grub_utf16_to_utf8(variable_name_string, variable_name,
variable_name_size) = '\0';
+ grub_printf("%pG-%s\n",&vendor_guid, variable_name_string);
+ dump_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_lsefivar (grub_extcmd_context_t ctxt,
+ int argc __attribute__((unused)), char **argv
__attribute__((unused)))
+{
+ if (ctxt->state[0].set)
+ return dump_efi_variables();
+
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, "one argument expected");
+}
+
+static grub_extcmd_t cmd;
+
+GRUB_MOD_INIT(lsefivar)
+{
+ cmd = grub_register_extcmd ("lsefivar", grub_cmd_lsefivar, 0,
N_("[-l]"), N_("Display UEFI variables."), options);
+}
+GRUB_MOD_FINI(lsefivar)
+{
+ grub_unregister_extcmd (cmd);
+}
+
+
--
2.49.0
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