Merge pull request #34348 from poettering/stub-efivar-tweaks

sd-stub: report stub location in efi vars

6 files changed, 63 insertions, 21 deletions

diff --git a/man/systemd-boot.xml b/man/systemd-boot.xml
index cc4504926c..0da919b127 100644
--- a/man/systemd-boot.xml
+++ b/man/systemd-boot.xml
@@ -429,13 +429,15 @@
       <varlistentry>
         <term><varname>LoaderDevicePartUUID</varname></term>
 
-        <listitem><para>Contains the partition UUID of the EFI System Partition the boot loader was run from. Set by
-        the boot
-        loader. <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
-        uses this information to automatically find the disk booted from, in order to discover various other partitions
-        on the same disk automatically.</para>
+        <listitem><para>Contains the partition UUID of the partition the boot loader has been started from on
+        the current boot (usually a EFI System Partition). Set by the boot loader. (Note that
+        <command>systemd-stub</command> will set this too, if not set yet, to support systems that directly
+        boot into a unified kernel image, bypassing any boot loader.)
+        <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        uses this information to automatically find the disk booted from, in order to discover various other
+        partitions on the same disk automatically.</para>
 
-        <xi:include href="version-info.xml" xpointer="v240"/></listitem>
+        <xi:include href="version-info.xml" xpointer="v220"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -516,12 +518,15 @@
       <varlistentry>
         <term><varname>LoaderImageIdentifier</varname></term>
 
-        <listitem><para>The path of executable of the boot loader used for the current boot, relative to the EFI System
-        Partition's root directory. Set by the boot loader. Use
-        <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to view this
-        data.</para>
+        <listitem><para>The file system path to the EFI executable of the boot loader for the current boot,
+        relative to the partition's root directory (i.e. relative to the partition indicated by
+        <varname>LoaderDevicePartUUID</varname>, see above). Set by the boot loader. (Note that
+        <command>systemd-stub</command> will set this too, if not set yet, to support systems that directly
+        boot into a unified kernel image, bypassing any boot loader.) Use
+        <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to view
+        this data.</para>
 
-        <xi:include href="version-info.xml" xpointer="v240"/></listitem>
+        <xi:include href="version-info.xml" xpointer="v220"/></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/man/systemd-stub.xml b/man/systemd-stub.xml
index 9f87f19f4c..dbc85d837a 100644
--- a/man/systemd-stub.xml
+++ b/man/systemd-stub.xml
@@ -459,12 +459,16 @@
       <varlistentry>
         <term><varname>LoaderDevicePartUUID</varname></term>
 
-        <listitem><para>Contains the partition UUID of the EFI System Partition the EFI image was run
-        from. <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        <listitem><para>Contains the partition UUID of the partition the boot loader has been started from on
+        the current boot (usually a EFI System Partition). If already set by the boot loader, this will
+        remain untouched by <command>systemd-stub</command>. If not set yet, this will be set to the
+        partition UUID of the partition the unified kernel is started from, in order to support systems that
+        directly boot into a unified kernel image, bypassing any boot loader.
+        <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
         uses this information to automatically find the disk booted from, in order to discover various other
         partitions on the same disk automatically.</para>
 
-        <xi:include href="version-info.xml" xpointer="v250"/></listitem>
+        <xi:include href="version-info.xml" xpointer="v224"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -481,12 +485,27 @@
       <varlistentry>
         <term><varname>LoaderImageIdentifier</varname></term>
 
-        <listitem><para>The path of EFI executable, relative to the EFI System Partition's root
-        directory. Use
+        <listitem><para>The file system path to the EFI executable of the boot loader for the current boot,
+        relative to the partition's root directory (i.e. relative to the partition indicated by
+        <varname>LoaderDevicePartUUID</varname>, see above). If not set yet, this will be set to the file
+        system path of the EFI executable of the booted unified kernel, in order to support systems that
+        directly boot into a unified kernel image, bypassing any boot loader.  Use
         <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to view
         this data.</para>
 
-        <xi:include href="version-info.xml" xpointer="v250"/></listitem>
+        <xi:include href="version-info.xml" xpointer="v237"/></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><varname>StubDevicePartUUID</varname></term>
+        <term><varname>StubImageIdentifier</varname></term>
+
+        <listitem><para>Similar to <varname>LoaderDevicePartUUID</varname> and
+        <varname>StubImageIdentifier</varname>, but indicates the location of the unified kernel image EFI
+        binary rather than the location of the boot loader binary, regardless if booted via a boot loader
+        or not.</para>
+
+        <xi:include href="version-info.xml" xpointer="v257"/></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/src/boot/bootctl-status.c b/src/boot/bootctl-status.c
index 113d27410f..192fddbf5e 100644
--- a/src/boot/bootctl-status.c
+++ b/src/boot/bootctl-status.c
@@ -378,12 +378,13 @@ int verb_status(int argc, char *argv[], void *userdata) {
                         { EFI_LOADER_FEATURE_SECUREBOOT_ENROLL,       "Enroll SecureBoot keys"                },
                         { EFI_LOADER_FEATURE_RETAIN_SHIM,             "Retain SHIM protocols"                 },
                         { EFI_LOADER_FEATURE_MENU_DISABLE,            "Menu can be disabled"                  },
+                        { EFI_LOADER_FEATURE_MULTI_PROFILE_UKI,       "Multi-Profile UKIs are supported"      },
                 };
                 static const struct {
                         uint64_t flag;
                         const char *name;
                 } stub_flags[] = {
-                        { EFI_STUB_FEATURE_REPORT_BOOT_PARTITION,     "Stub sets ESP information"                                   },
+                        { EFI_STUB_FEATURE_REPORT_BOOT_PARTITION,     "Stub sets loader partition information"                      },
                         { EFI_STUB_FEATURE_PICK_UP_CREDENTIALS,       "Picks up credentials from boot partition"                    },
                         { EFI_STUB_FEATURE_PICK_UP_SYSEXTS,           "Picks up system extension images from boot partition"        },
                         { EFI_STUB_FEATURE_PICK_UP_CONFEXTS,          "Picks up configuration extension images from boot partition" },
@@ -392,6 +393,8 @@ int verb_status(int argc, char *argv[], void *userdata) {
                         { EFI_STUB_FEATURE_CMDLINE_ADDONS,            "Pick up .cmdline from addons"                                },
                         { EFI_STUB_FEATURE_CMDLINE_SMBIOS,            "Pick up .cmdline from SMBIOS Type 11"                        },
                         { EFI_STUB_FEATURE_DEVICETREE_ADDONS,         "Pick up .dtb from addons"                                    },
+                        { EFI_STUB_FEATURE_MULTI_PROFILE_UKI,         "Stub understands profile selector"                           },
+                        { EFI_STUB_FEATURE_REPORT_STUB_PARTITION,     "Stub sets stub partition information"                        },
                 };
                 _cleanup_free_ char *fw_type = NULL, *fw_info = NULL, *loader = NULL, *loader_path = NULL, *stub = NULL;
                 sd_id128_t loader_part_uuid = SD_ID128_NULL;
diff --git a/src/boot/efi/export-vars.c b/src/boot/efi/export-vars.c
index 3f59922a7e..12fbd10b05 100644
--- a/src/boot/efi/export-vars.c
+++ b/src/boot/efi/export-vars.c
@@ -10,7 +10,8 @@ void export_common_variables(EFI_LOADED_IMAGE_PROTOCOL *loaded_image) {
         assert(loaded_image);
 
         /* Export the device path this image is started from, if it's not set yet */
-        if (efivar_get_raw(MAKE_GUID_PTR(LOADER), u"LoaderDevicePartUUID", NULL, NULL) != EFI_SUCCESS) {
+        if (loaded_image->DeviceHandle &&
+            efivar_get_raw(MAKE_GUID_PTR(LOADER), u"LoaderDevicePartUUID", NULL, NULL) != EFI_SUCCESS) {
                 _cleanup_free_ char16_t *uuid = disk_get_part_uuid(loaded_image->DeviceHandle);
                 if (uuid)
                         efivar_set_str16(MAKE_GUID_PTR(LOADER), u"LoaderDevicePartUUID", uuid, 0);
@@ -22,8 +23,8 @@ void export_common_variables(EFI_LOADED_IMAGE_PROTOCOL *loaded_image) {
          * in which case there's simple nothing to set for us. (The UEFI spec doesn't really say who's wrong
          * here, i.e. whether FilePath may be NULL or not, hence handle this gracefully and check if FilePath
          * is non-NULL explicitly.) */
-        if (efivar_get_raw(MAKE_GUID_PTR(LOADER), u"LoaderImageIdentifier", NULL, NULL) != EFI_SUCCESS &&
-            loaded_image->FilePath) {
+        if (loaded_image->FilePath &&
+            efivar_get_raw(MAKE_GUID_PTR(LOADER), u"LoaderImageIdentifier", NULL, NULL) != EFI_SUCCESS) {
                 _cleanup_free_ char16_t *s = NULL;
                 if (device_path_to_str(loaded_image->FilePath, &s) == EFI_SUCCESS)
                         efivar_set_str16(MAKE_GUID_PTR(LOADER), u"LoaderImageIdentifier", s, 0);
diff --git a/src/boot/efi/stub.c b/src/boot/efi/stub.c
index 0ace97013f..a5b1c50acb 100644
--- a/src/boot/efi/stub.c
+++ b/src/boot/efi/stub.c
@@ -153,6 +153,7 @@ static void export_stub_variables(EFI_LOADED_IMAGE_PROTOCOL *loaded_image, unsig
                 EFI_STUB_FEATURE_CMDLINE_SMBIOS |           /* We support extending kernel cmdline from SMBIOS Type #11 */
                 EFI_STUB_FEATURE_DEVICETREE_ADDONS |        /* We pick up .dtb addons */
                 EFI_STUB_FEATURE_MULTI_PROFILE_UKI |        /* We grok the "@1" profile command line argument */
+                EFI_STUB_FEATURE_REPORT_STUB_PARTITION |    /* We set StubDevicePartUUID + StubImageIdentifier */
                 0;
 
         assert(loaded_image);
@@ -164,6 +165,18 @@ static void export_stub_variables(EFI_LOADED_IMAGE_PROTOCOL *loaded_image, unsig
         (void) efivar_set_uint64_le(MAKE_GUID_PTR(LOADER), u"StubFeatures", stub_features, 0);
 
         (void) efivar_set_uint64_str16(MAKE_GUID_PTR(LOADER), u"StubProfile", profile, 0);
+
+        if (loaded_image->DeviceHandle) {
+                _cleanup_free_ char16_t *uuid = disk_get_part_uuid(loaded_image->DeviceHandle);
+                if (uuid)
+                        efivar_set_str16(MAKE_GUID_PTR(LOADER), u"StubDevicePartUUID", uuid, 0);
+        }
+
+        if (loaded_image->FilePath) {
+                _cleanup_free_ char16_t *s = NULL;
+                if (device_path_to_str(loaded_image->FilePath, &s) == EFI_SUCCESS)
+                        efivar_set_str16(MAKE_GUID_PTR(LOADER), u"StubImageIdentifier", s, 0);
+        }
 }
 
 static bool parse_profile_from_cmdline(char16_t **cmdline, unsigned *ret_profile) {
diff --git a/src/fundamental/efivars-fundamental.h b/src/fundamental/efivars-fundamental.h
index e18d59ff60..f002e81b53 100644
--- a/src/fundamental/efivars-fundamental.h
+++ b/src/fundamental/efivars-fundamental.h
@@ -36,6 +36,7 @@
 #define EFI_STUB_FEATURE_DEVICETREE_ADDONS         (UINT64_C(1) << 7)
 #define EFI_STUB_FEATURE_PICK_UP_CONFEXTS          (UINT64_C(1) << 8)
 #define EFI_STUB_FEATURE_MULTI_PROFILE_UKI         (UINT64_C(1) << 9)
+#define EFI_STUB_FEATURE_REPORT_STUB_PARTITION     (UINT64_C(1) << 10)
 
 typedef enum SecureBootMode {
         SECURE_BOOT_UNSUPPORTED,