ppc64le: fix issues using core.elf on boot media

Resolves: #2143420
Signed-off-by: Robbie Harwood <rharwood@redhat.com>

0308-Skip-diskfilter-on-powerpc-CDs.patch

@@ -0,0 +1,59 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Robbie Harwood <rharwood@redhat.com>
+Date: Thu, 12 Jan 2023 16:03:03 -0500
+Subject: [PATCH] Skip diskfilter on powerpc CDs
+
+Prior to this change, on ppc64le with part_msdos and the mdraid* modules
+enabled, we see:
+
+    disk/diskfilter.c:191: scanning ieee1275/cdrom
+    kern/disk.c:196: Opening `ieee1275/cdrom'...
+    disk/ieee1275/ofdisk.c:477: Opening `cdrom'.
+    disk/ieee1275/ofdisk.c:502: MAX_RETRIES set to 20
+    kern/disk.c:288: Opening `ieee1275/cdrom' succeeded.
+    disk/diskfilter.c:136: Scanning for DISKFILTER devices on disk ieee1275/cdrom
+    partmap/msdos.c:184: partition 0: flag 0x80, type 0x96, start 0x0, len
+    0x6a5d70
+    disk/diskfilter.c:136: Scanning for DISKFILTER devices on disk ieee1275/cdrom
+    SCSI-DISK: Access beyond end of device !
+    SCSI-DISK: Access beyond end of device !
+    SCSI-DISK: Access beyond end of device !
+    SCSI-DISK: Access beyond end of device !
+    SCSI-DISK: Access beyond end of device !
+    disk/ieee1275/ofdisk.c:578: MAX_RETRIES set to 20
+
+These latter two lines repeat many times, eventually ending in:
+
+    kern/disk.c:388: ieee1275/cdrom read failed
+    error: ../../grub-core/disk/ieee1275/ofdisk.c:608:failure reading sector
+    0x1a9720 from `ieee1275/cdrom'.
+
+and the system drops to a "grub>" prompt.
+
+The firmware and the iso image appear to diagree on the blocksize (512
+vs. 2048), and the diskfilter RAID probing is too much for it.  We won't
+be seeing RAID on bootable CDs, so just turn it off.
+
+Signed-off-by: Robbie Harwood <rharwood@redhat.com>
+(cherry picked from commit 35614da6ef0296d1a2d1583ae23822230c25a334)
+(cherry picked from commit e908b38eabd5011865b3bfe0873b053ee82de217)
+---
+ grub-core/disk/diskfilter.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/grub-core/disk/diskfilter.c b/grub-core/disk/diskfilter.c
+index 7cdffe3ebd..f9140f7493 100644
+--- a/grub-core/disk/diskfilter.c
++++ b/grub-core/disk/diskfilter.c
+@@ -133,6 +133,11 @@ scan_disk_partition_iter (grub_disk_t disk, grub_partition_t p, void *data)
+   struct grub_diskfilter_pv_id id;
+   grub_diskfilter_t diskfilter;
+ 
++#ifdef __powerpc__
++  if (!grub_strcmp (name, "ieee1275/cdrom"))
++    return 0;
++#endif
++
+   grub_dprintf ("diskfilter", "Scanning for DISKFILTER devices on disk %s\n",
+ 		name);
+ #ifdef GRUB_UTIL

0309-Fix-prefix-and-root-on-ppc64le-CDs.patch

@@ -0,0 +1,54 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Robbie Harwood <rharwood@redhat.com>
+Date: Fri, 13 Jan 2023 12:36:29 -0500
+Subject: [PATCH] Fix prefix and root on ppc64le CDs
+
+CHRP requires grub at /boot/grub.  On CDs, this means any other prefix
+will be invalid.  In particular, a distro grub might prefer /grub2 - but
+prefix is hardcoded into the signed core.elf, and will always be wrong
+here.
+
+Also work around a conflict between OF naming and that used by
+part_msdos: on CDs, we always want the raw device.  This fixes an issue
+where grub would successfully load the menu from an image, but then
+produce the error:
+
+    error: ../../grub-core/net/net.c:1552:disk `ieee1275/cdrom,0' not found.
+
+and fail to boot further.
+
+Signed-off-by: Robbie Harwood <rharwood@redhat.com>
+(cherry picked from commit 68e5981a5e808a32350aca4a2414717fa4605ca0)
+(cherry picked from commit 19c45257cc29845adedc3931eed577e97534f8f1)
+---
+ grub-core/kern/main.c | 17 +++++++++++++++++
+ 1 file changed, 17 insertions(+)
+
+diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
+index 4c4e6912f9..6989da5618 100644
+--- a/grub-core/kern/main.c
++++ b/grub-core/kern/main.c
+@@ -278,6 +278,23 @@ grub_set_prefix_and_root (void)
+ 	}
+ 
+       grub_env_set ("root", device);
++
++#ifdef __powerpc__
++      /* When booting from a CD, if part_msdos is enabled, grub will detect
++         and create access points starting at (ieee1275/cdrom,msdos1).
++         However, the device detection and OF name transformation will produce
++         a device named (ieee1275/cdrom,0) - i.e., missing the msdos and also
++         differently indexed.  Furthermore, CHRP mandates boot/grub as prefix,
++         but our signed images are built with /grub2 to reflect installed
++         systems.  Just ignore both messes.
++       */
++      if (!grub_strncmp (device[0] == '(' ? device + 1 : device,
++                         "ieee1275/cdrom", grub_strlen ("ieee1275/cdrom")))
++        {
++          grub_env_set ("prefix", "/boot/grub");
++          grub_env_set ("root", "ieee1275/cdrom");
++        }
++#endif
+     }
+ 
+   grub_free (device);

grub.patches

@@ -305,3 +305,5 @@ Patch0304: 0304-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch
 Patch0305: 0305-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch
 Patch0306: 0306-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch
 Patch0307: 0307-Correction-in-vector-5-values.patch
+Patch0308: 0308-Skip-diskfilter-on-powerpc-CDs.patch
+Patch0309: 0309-Fix-prefix-and-root-on-ppc64le-CDs.patch

grub2.spec

@@ -14,7 +14,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.06
-Release:	52%{?dist}
+Release:	53%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -532,6 +532,10 @@ mv ${EFI_HOME}/grub.cfg.stb ${EFI_HOME}/grub.cfg
 %endif
 
 %changelog
+* Fri Jan 13 2023 Robbie Harwood <rharwood@redhat.com> - 2.06-53
+- ppc64le: fix issues using core.elf on boot media
+- Resolves: #2143420
+
 * Wed Dec 14 2022 Robbie Harwood <rharwood@redhat.com> - 2.06-52
 - ppc64le: fix lpar cas5
 - Resolves: #2153071