GPT partitions have a name property that is useable for identifying the
partition in Linux via root=PARTLABEL=<partlabel> boot argument or via
/dev/disk/by-partlabel/<partlabel>. Add support for searching for it in
GRUB. Compared to the fs label, the partition label does not change when
reformatting a partition.
Signed-off-by: Daniel Wagenknecht <dwagenkne...@emlix.com>
---
This is a resend of a patch from 2020. Glenn Washburn suggested to rebase and
resend with Daniel Kiper explicitely added to the recipients.
The rebase required some changes to adapt to the changes in no_floppy search
flags but is otherwise unchanged.
Tested by manually searching for a partition by GPT partition label in grub in
qemu.
Cheers
Daniel Wagenknecht
grub-core/Makefile.core.def | 5 +++
grub-core/commands/search.c | 57 +++++++++++++++++++++++++++
grub-core/commands/search_partlabel.c | 5 +++
grub-core/commands/search_wrap.c | 9 ++++-
include/grub/search.h | 3 ++
5 files changed, 77 insertions(+), 2 deletions(-)
create mode 100644 grub-core/commands/search_partlabel.c
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 5212dfab1..d76c47113 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1084,6 +1084,11 @@ module = {
common = commands/search_label.c;
};
+module = {
+ name = search_part_label;
+ common = commands/search_partlabel.c;
+};
+
module = {
name = setpci;
common = commands/setpci.c;
diff --git a/grub-core/commands/search.c b/grub-core/commands/search.c
index 263f1501c..56aa97278 100644
--- a/grub-core/commands/search.c
+++ b/grub-core/commands/search.c
@@ -30,6 +30,8 @@
#include <grub/i18n.h>
#include <grub/disk.h>
#include <grub/partition.h>
+#include <grub/gpt_partition.h>
+#include <grub/charset.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -54,6 +56,29 @@ struct search_ctx
int is_cache;
};
+/* helper for grub_search_part_label */
+static char *
+get_utf8 (grub_uint8_t *in, grub_size_t len)
+{
+ grub_uint8_t *buf;
+ grub_uint16_t *tmp;
+ grub_size_t i;
+
+ buf = grub_malloc (len * GRUB_MAX_UTF8_PER_UTF16 + 1);
+ tmp = grub_malloc (len * sizeof (tmp[0]));
+ if (!buf || !tmp)
+ {
+ grub_free (buf);
+ grub_free (tmp);
+ return NULL;
+ }
+ for (i = 0; i < len; i++)
+ tmp[i] = grub_le_to_cpu16 (grub_get_unaligned16 (in + 2 * i));
+ *grub_utf16_to_utf8 (buf, tmp, len) = '\0';
+ grub_free (tmp);
+ return (char *) buf;
+}
+
/* Helper for FUNC_NAME. */
static int
iterate_device (const char *name, void *data)
@@ -110,6 +135,34 @@ iterate_device (const char *name, void *data)
}
grub_free (buf);
}
+#elif defined (DO_SEARCH_PART_LABEL)
+ {
+ grub_device_t dev;
+ char *buf;
+
+ dev = grub_device_open (name);
+ if (dev && dev->disk && dev->disk->partition)
+ {
+ grub_partition_t p = dev->disk->partition;
+ grub_disk_t disk = grub_disk_open(dev->disk->name);
+
+ if (!disk)
+ return 1;
+ if (grub_strcmp (p->partmap->name, "gpt") == 0)
+ {
+ struct grub_gpt_partentry gptdata;
+
+ if (grub_disk_read (disk, p->offset, p->index, sizeof (gptdata),
&gptdata))
+ return 1;
+ buf = get_utf8(gptdata.name, 36);
+ if (compare_fn (buf, ctx->key) == 0)
+ found = 1;
+ grub_free (buf);
+ }
+ grub_disk_close(disk);
+ grub_device_close (dev);
+ }
+ }
#else
{
/* SEARCH_FS_UUID or SEARCH_LABEL */
@@ -333,6 +386,8 @@ static grub_command_t cmd;
#ifdef DO_SEARCH_FILE
GRUB_MOD_INIT(search_fs_file)
+#elif defined (DO_SEARCH_PART_LABEL)
+GRUB_MOD_INIT(search_part_label)
#elif defined (DO_SEARCH_FS_UUID)
GRUB_MOD_INIT(search_fs_uuid)
#else
@@ -347,6 +402,8 @@ GRUB_MOD_INIT(search_label)
#ifdef DO_SEARCH_FILE
GRUB_MOD_FINI(search_fs_file)
+#elif defined (DO_SEARCH_PART_LABEL)
+GRUB_MOD_FINI(search_part_label)
#elif defined (DO_SEARCH_FS_UUID)
GRUB_MOD_FINI(search_fs_uuid)
#else
diff --git a/grub-core/commands/search_partlabel.c
b/grub-core/commands/search_partlabel.c
new file mode 100644
index 000000000..8784d909e
--- /dev/null
+++ b/grub-core/commands/search_partlabel.c
@@ -0,0 +1,5 @@
+#define DO_SEARCH_PART_LABEL 1
+#define FUNC_NAME grub_search_part_label
+#define COMMAND_NAME "search.part_label"
+#define HELP_MESSAGE N_("Search devices by GPT partition label. If VARIABLE is
specified, the first device found is set to a variable.")
+#include "search.c"
diff --git a/grub-core/commands/search_wrap.c b/grub-core/commands/search_wrap.c
index 318581f3b..6d1935bed 100644
--- a/grub-core/commands/search_wrap.c
+++ b/grub-core/commands/search_wrap.c
@@ -34,6 +34,8 @@ static const struct grub_arg_option options[] =
{"file", 'f', 0, N_("Search devices by a file."), 0, 0},
{"label", 'l', 0, N_("Search devices by a filesystem label."),
0, 0},
+ {"part-label", 0, 0, N_("Search devices by a GPT partition label."),
+ 0, 0},
{"fs-uuid", 'u', 0, N_("Search devices by a filesystem
UUID."),
0, 0},
{"set", 's', GRUB_ARG_OPTION_OPTIONAL,
@@ -71,6 +73,7 @@ enum options
{
SEARCH_FILE,
SEARCH_LABEL,
+ SEARCH_PART_LABEL,
SEARCH_FS_UUID,
SEARCH_SET,
SEARCH_NO_FLOPPY,
@@ -191,6 +194,8 @@ grub_cmd_search (grub_extcmd_context_t ctxt, int argc, char
**args)
if (state[SEARCH_LABEL].set)
grub_search_label (id, var, flags, hints, nhints);
+ else if (state[SEARCH_PART_LABEL].set)
+ grub_search_part_label (id, var, flags, hints, nhints);
else if (state[SEARCH_FS_UUID].set)
grub_search_fs_uuid (id, var, flags, hints, nhints);
else if (state[SEARCH_FILE].set)
@@ -212,8 +217,8 @@ GRUB_MOD_INIT(search)
GRUB_COMMAND_FLAG_EXTRACTOR |
GRUB_COMMAND_ACCEPT_DASH,
N_("[-f|-l|-u|-s|-n] [--hint HINT [--hint HINT] ...]"
" NAME"),
- N_("Search devices by file, filesystem label"
- " or filesystem UUID."
+ N_("Search devices by file, filesystem label,"
+ " GPT partition label or filesystem UUID."
" If --set is specified, the first device found is"
" set to a variable. If no variable name is"
" specified, `root' is used."),
diff --git a/include/grub/search.h b/include/grub/search.h
index ffd2411ca..ce61078a0 100644
--- a/include/grub/search.h
+++ b/include/grub/search.h
@@ -35,5 +35,8 @@ void grub_search_fs_uuid (const char *key, const char *var,
void grub_search_label (const char *key, const char *var,
enum search_flags flags,
char **hints, unsigned nhints);
+void grub_search_part_label (const char *key, const char *var,
+ enum search_flags flags,
+ char **hints, unsigned nhints);
#endif
--
2.36.0
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