From a8c47660bbbcc2ffc483beaa17d5c806f73849b3 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 23 Jan 2019 11:34:31 +0100
Subject: [PATCH] dissect: automatically detect boot loader spec $BOOT
 partition

The boot loader spec supports two places to store boot loader
configuration: the ESP and a generic replacement for it in case the ESP
is not available or not suitable. Let's look for both.
---
 src/shared/dissect-image.c | 65 +++++++++++++++++++++++++++++++-------
 src/shared/dissect-image.h |  1 +
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index 94df2fe255f..2dbc0bdb3d4 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -495,6 +495,14 @@ int dissect_image(
 
                                 designator = PARTITION_ESP;
                                 fstype = "vfat";
+
+                        } else if (sd_id128_equal(type_id, GPT_XBOOTLDR)) {
+
+                                if (pflags & GPT_FLAG_NO_AUTO)
+                                        continue;
+
+                                designator = PARTITION_XBOOTLDR;
+                                rw = !(pflags & GPT_FLAG_READ_ONLY);
                         }
 #ifdef GPT_ROOT_NATIVE
                         else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) {
@@ -610,21 +618,53 @@ int dissect_image(
 
                 } else if (is_mbr) {
 
-                        if (pflags != 0x80) /* Bootable flag */
-                                continue;
+                        switch (blkid_partition_get_type(pp)) {
 
-                        if (blkid_partition_get_type(pp) != 0x83) /* Linux partition */
-                                continue;
+                        case 0x83: /* Linux partition */
+
+                                if (pflags != 0x80) /* Bootable flag */
+                                        continue;
 
-                        if (generic_node)
-                                multiple_generic = true;
-                        else {
-                                generic_nr = nr;
-                                generic_rw = true;
-                                generic_node = strdup(node);
-                                if (!generic_node)
+                                if (generic_node)
+                                        multiple_generic = true;
+                                else {
+                                        generic_nr = nr;
+                                        generic_rw = true;
+                                        generic_node = strdup(node);
+                                        if (!generic_node)
+                                                return -ENOMEM;
+                                }
+
+                                break;
+
+                        case 0xEA: { /* Boot Loader Spec extended $BOOT partition */
+                                _cleanup_free_ char *n = NULL;
+                                sd_id128_t id = SD_ID128_NULL;
+                                const char *sid;
+
+                                /* First one wins */
+                                if (m->partitions[PARTITION_XBOOTLDR].found)
+                                        continue;
+
+                                sid = blkid_partition_get_uuid(pp);
+                                if (sid)
+                                        (void) sd_id128_from_string(sid, &id);
+
+                                n = strdup(node);
+                                if (!n)
                                         return -ENOMEM;
-                        }
+
+                                m->partitions[PARTITION_XBOOTLDR] = (DissectedPartition) {
+                                        .found = true,
+                                        .partno = nr,
+                                        .rw = true,
+                                        .architecture = _ARCHITECTURE_INVALID,
+                                        .node = TAKE_PTR(n),
+                                        .uuid = id,
+                                };
+
+                                break;
+                        }}
                 }
         }
 
@@ -1497,6 +1537,7 @@ static const char *const partition_designator_table[] = {
         [PARTITION_HOME] = "home",
         [PARTITION_SRV] = "srv",
         [PARTITION_ESP] = "esp",
+        [PARTITION_XBOOTLDR] = "xbootldr",
         [PARTITION_SWAP] = "swap",
         [PARTITION_ROOT_VERITY] = "root-verity",
         [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity",
diff --git a/src/shared/dissect-image.h b/src/shared/dissect-image.h
index f50b40ea115..ded43f331a5 100644
--- a/src/shared/dissect-image.h
+++ b/src/shared/dissect-image.h
@@ -29,6 +29,7 @@ enum  {
         PARTITION_HOME,
         PARTITION_SRV,
         PARTITION_ESP,
+        PARTITION_XBOOTLDR,
         PARTITION_SWAP,
         PARTITION_ROOT_VERITY, /* verity data for the PARTITION_ROOT partition */
         PARTITION_ROOT_SECONDARY_VERITY, /* verity data for the PARTITION_ROOT_SECONDARY partition */
-- 
2.47.3