[PATCH v8 6/6] ieee1275: support added for multiple nvme bootpaths

Avnish Chouhan
2026-02-23T13:46:04Z

This patch sets mupltiple NVMe boot-devices for more robust boot.
Scenario where NVMe multipaths are available, all the available bootpaths (Max 5)
will be added as the boot-device.

Signed-off-by: Avnish Chouhan <avnish@linux.ibm.com>
---
grub-core/osdep/unix/platform.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
grub-core/osdep/linux/ofpath.c | 4 ++--
include/grub/util/install.h | 3 +++
include/grub/util/ofpath.h | 4 ++++
4 file changed, 126 insertions(+), 3 deletion(-)

diff --git a/grub-core/osdep/unix/platform.c b/grub-core/osdep/unix/platform.c
index de71221..4632f41 100644
--- a/grub-core/osdep/unix/platform.c
+++ b/grub-core/osdep/unix/platform.c
@@ -28,6 +28,10 @@
#include <dirent.h>
#include <string.h>
#include <errno.h>
+#include <grub/util/ofpath.h>
+#include <stdbool.h>
+
+#define BOOTDEV_BUFFER 1000

static char *
get_ofpathname (const char *dev)
@@ -176,6 +180,107 @@ grub_install_register_efi (grub_device_t efidir_grub_dev,
return ret;
}

+
+char *
+add_multiple_nvme_bootdevices (const char *install_device)
+{
+ char *sysfs_path, *nvme_ns, *ptr, *non_splitter_path;
+ unsigned int nsid;
+ char *multipath_boot, *ofpath, *ext_dir;
+ struct dirent *ep, *splitter_ep;
+ DIR *dp, *splitter_dp;
+ char *cntl_id, *dirR1, *dirR2, *splitter_info_path;
+ bool is_FC = false, is_splitter = false;
+
+ nvme_ns = grub_strstr (install_device, "nvme");
+ nsid = of_path_get_nvme_nsid (nvme_ns);
+ if (nsid == 0)
+ return NULL;
+
+ sysfs_path = nvme_get_syspath (nvme_ns);
+ ofpath = xasprintf ("%s", get_ofpathname (nvme_ns));
+
+ if (grub_strstr (ofpath, "fibre-channel"))
+ {
+ strcat (sysfs_path, "/device");
+ is_FC = true;
+ }
+ else
+ {
+ strcat (sysfs_path, "/subsystem");
+ is_FC = false;
+ }
+ if (is_FC == false)
+ {
+ cntl_id = grub_strstr (nvme_ns, "e");
+ dirR1 = xasprintf ("nvme%c",cntl_id[1]);
+
+ splitter_info_path = xasprintf ("/sys/block/%s/device", nvme_ns);
+ splitter_dp = opendir (splitter_info_path);
+ if (!splitter_dp)
+ return NULL;
+
+ while ((splitter_ep = readdir (splitter_dp)) != NULL)
+ {
+ if (grub_strstr (splitter_ep->d_name, "nvme"))
+ {
+ if (grub_strstr (splitter_ep->d_name, dirR1))
+ continue;
+
+ ext_dir = grub_strchr (splitter_ep->d_name, 'e');
+ if (grub_strchr (ext_dir, 'n') == NULL)
+ {
+ dirR2 = xasprintf("%s", splitter_ep->d_name);
+ is_splitter = true;
+ break;
+ }
+ }
+ }
+ closedir (splitter_dp);
+ }
+ sysfs_path = xrealpath (sysfs_path);
+ dp = opendir (sysfs_path);
+ if (!dp)
+ return NULL;
+
+ ptr = multipath_boot = xmalloc (BOOTDEV_BUFFER);
+ if (is_splitter == false && is_FC == false)
+ {
+ non_splitter_path = xasprintf ("%s/namespace@%x:1 ", get_ofpathname (dirR1), nsid);
+ strncpy (ptr, non_splitter_path, strlen (non_splitter_path));
+ ptr += strlen (non_splitter_path);
+ free (non_splitter_path);
+ }
+ else
+ {
+ while ((ep = readdir (dp)) != NULL)
+ {
+ char *path;
+
+ if (grub_strstr (ep->d_name, "nvme") != NULL)
+ {
+ if (is_FC == false && grub_strstr (ep->d_name, dirR1) == NULL &&
+ grub_strstr (ep->d_name, dirR2) == NULL)
+ continue;
+ path = xasprintf ("%s/namespace@%x ", get_ofpathname (ep->d_name), nsid);
+ if ((strlen (multipath_boot) + strlen (path)) > BOOTDEV_BUFFER)
+ {
+ grub_util_warn (_("Maximum five entries are allowed in the bootlist"));
+ free (path);
+ break;
+ }
+ strncpy (ptr, path, strlen (path));
+ ptr += strlen (path);
+ free (path);
+ }
+ }
+ }
+ *--ptr = '\0';
+ closedir (dp);
+
+ return multipath_boot;
+}
+
void
grub_install_register_ieee1275 (int is_prep, const char *install_device,
int partno, const char *relpath)
@@ -215,8 +320,19 @@ grub_install_register_ieee1275 (int is_prep, const char *install_device,
}
*ptr = '\0';
}
+ else if (grub_strstr (install_device, "nvme"))
+ {
+ boot_device = add_multiple_nvme_bootdevices (install_device);
+ }
else
- boot_device = get_ofpathname (install_device);
+ {
+ boot_device = get_ofpathname (install_device);
+ if (grub_strstr (boot_device, "nvme-of"))
+ {
+ free (boot_device);
+ boot_device = add_multiple_nvme_bootdevices (install_device);
+ }
+ }

if (grub_util_exec ((const char * []){ "nvsetenv", "boot-device",
boot_device, NULL }))
diff --git a/grub-core/osdep/linux/ofpath.c b/grub-core/osdep/linux/ofpath.c
index 7158c8c..3a778e0 100644
--- a/grub-core/osdep/linux/ofpath.c
+++ b/grub-core/osdep/linux/ofpath.c
@@ -209,7 +209,7 @@ find_obppath (const char *sysfs_path_orig)
}
}

-static char *
+char *
xrealpath (const char *in)
{
char *out;
@@ -684,7 +684,7 @@ of_path_get_nvme_nsid (const char* devname)
return nsid;
}

-static char *
+char *
nvme_get_syspath (const char *nvmedev)
{
char *sysfs_path;
diff --git a/include/grub/util/install.h b/include/grub/util/install.h
index 51f3b13..a67e225 100644
--- a/include/grub/util/install.h
+++ b/include/grub/util/install.h
@@ -235,6 +235,9 @@ grub_install_register_efi (grub_device_t efidir_grub_dev,
const char *efifile_path,
const char *efi_distributor);

+char *
+add_multiple_nvme_bootdevices (const char *install_device);
+
void
grub_install_register_ieee1275 (int is_prep, const char *install_device,
int partno, const char *relpath);
diff --git a/include/grub/util/ofpath.h b/include/grub/util/ofpath.h
index 5962322..78e78e7 100644
--- a/include/grub/util/ofpath.h
+++ b/include/grub/util/ofpath.h
@@ -30,5 +30,9 @@ int add_filename_to_pile (char *filename, struct ofpath_files_list_root* root);
void find_file (char* filename, char* directory, struct ofpath_files_list_root* root, int max_depth, int depth);
char* of_find_fc_host (char* host_wwpn);
void free_ofpath_files_list (struct ofpath_files_list_root* root);
+char* nvme_get_syspath (const char *nvmedev);
+unsigned int of_path_get_nvme_nsid (const char* devname);
+char* xrealpath (const char *in);
+

#endif /* ! GRUB_OFPATH_MACHINE_UTIL_HEADER */
--
2.50.1 (Apple Git-155)