Add --efi-label argument to bootctl to control the name of the boot

entry.

By default an entry named "Linux Boot Manager" is created (which is the
previous behavior). With the flag the name of the entry can be
controlled, which is useful when installing systemd-boot to multiple ESP
partitions and having uniquely named entries.

Fixes systemd#17044.

man/bootctl.xml

@@ -377,6 +377,12 @@
         <listitem><para>Install binaries for all supported EFI architectures (this implies <option>--no-variables</option>).</para></listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><option>--efi-label=</option></term>
+        <listitem><para>Name of the entry added to the firmware's boot loader list. Defaults to <literal>Linux
+        Boot Manager</literal>.</para></listitem>
+      </varlistentry>
+
       <xi:include href="standard-options.xml" xpointer="no-pager"/>
       <xi:include href="standard-options.xml" xpointer="json" />
       <xi:include href="standard-options.xml" xpointer="help"/>

src/boot/bootctl.c

@@ -85,13 +85,15 @@ static enum {
         ARG_INSTALL_SOURCE_HOST,
         ARG_INSTALL_SOURCE_AUTO,
 } arg_install_source = ARG_INSTALL_SOURCE_AUTO;
+static char *arg_efi_label = NULL;
 
 STATIC_DESTRUCTOR_REGISTER(arg_esp_path, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_xbootldr_path, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_install_layout, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_entry_token, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_root, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_image, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_efi_label, freep);
 
 static const char *arg_dollar_boot_path(void) {
         /* $BOOT shall be the XBOOTLDR partition if it exists, and otherwise the ESP */
@@ -1139,13 +1141,13 @@ static int install_variables(const char *esp_path,
                                        "Failed to determine current boot order: %m");
 
         if (first || r == 0) {
-                r = efi_add_boot_option(slot, "Linux Boot Manager",
+                r = efi_add_boot_option(slot, arg_efi_label ?: "Linux Boot Manager",
                                         part, pstart, psize,
                                         uuid, path);
                 if (r < 0)
                         return log_error_errno(r, "Failed to create EFI Boot variable entry: %m");
 
-                log_info("Created EFI boot entry \"Linux Boot Manager\".");
+                log_info("Created EFI boot entry \"%s\".", arg_efi_label ?: "Linux Boot Manager");
         }
 
         return insert_into_order(slot, first);
@@ -1465,6 +1467,8 @@ static int help(int argc, char *argv[], void *userdata) {
                "                       Generate JSON output\n"
                "     --all-architectures\n"
                "                       Install all supported EFI architectures\n"
+               "     --efi-label=LABEL\n"
+               "                       Name of the boot loader entry\n"
                "\nSee the %2$s for details.\n",
                program_invocation_short_name,
                link,
@@ -1491,6 +1495,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_ENTRY_TOKEN,
                 ARG_JSON,
                 ARG_ARCH_ALL,
+                ARG_EFI_LABEL,
         };
 
         static const struct option options[] = {
@@ -1514,6 +1519,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "entry-token",               required_argument, NULL, ARG_ENTRY_TOKEN               },
                 { "json",                      required_argument, NULL, ARG_JSON                      },
                 { "all-architectures",         no_argument,       NULL, ARG_ARCH_ALL                  },
+                { "efi-label",                 required_argument, NULL, ARG_EFI_LABEL                 },
                 {}
         };
 
@@ -1647,6 +1653,22 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_arch_all = true;
                         break;
 
+                case ARG_EFI_LABEL:
+                        if (isempty(optarg) || !string_is_safe(optarg)) {
+                                _cleanup_free_ char *escaped = NULL;
+
+                                escaped = cescape(optarg);
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Invalid --efi-label=: %s", strna(escaped));
+                        }
+                        if (strlen(optarg) > 1024)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "--efi-label= too long: %zu > 1024", strlen(optarg));
+                        r = free_and_strdup(&arg_efi_label, optarg);
+                        if (r < 0)
+                                return log_oom();
+                        break;
+
                 case '?':
                         return -EINVAL;