[PATCH kernel-helper v2] fix #7223: proxmox-boot: add memtest86 as entry to all boot-loaders

[Stoiko Ivanov <s.ivanov@proxmox.com>]

memtest86+ ships a config-snippet for grub configuration, and is thus
present on installations using grub (although currently not functional
when secure-boot is enabled), without proxmox-boot-tool.

adding an equivalent entry for memtest86+ on systems, where
proxmox-boot-tool manages the boot-loader seems like an improvement
and a step to having similar functionality in our different
boot-loader setups.

Tested by installing proxmox-kernel-helper with this patch and running
proxmox-boot-tool reinit, followed by rebooting into memtest86+ on a
systemd-booted system. Additionally tested the addition of the entry
in grub, by both installing on a system booted in legacy bios mode and
one where I ran `proxmox-boot-tool init /dev/sdX2 grub` (after
formatting). To get the entry in grub a `proxmox-boot-tool refresh`
call is needed (so that `update-grub` generates the entries). As this
will get called anyways upon installation from ISO, and on each
kernel-upgrade I decided against calling it in `proxmox-boot-tool
init|reinit` additionally.

Suggested-by: Daniel Herzig <d.herzig@proxmox.com>
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
this patch supersedes:
https://lore.proxmox.com/all/20260225183621.201783-1-s.ivanov@proxmox.com/

v1->v2
* added a reference to #7223 - thanks @Laurentiu for the hint!
* additionally add memtest to grub-booted systems - thanks @Daniel Herzig for
  the feedback and additional tests!

 src/bin/proxmox-boot-tool | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/bin/proxmox-boot-tool b/src/bin/proxmox-boot-tool
index 95d699d..ee04193 100755
--- a/src/bin/proxmox-boot-tool
+++ b/src/bin/proxmox-boot-tool
@@ -158,7 +158,13 @@ init_bootloader() {
 		fi
 	fi
 
+
 	if [ -d /sys/firmware/efi ]; then
+		memtest=memtest86+x64.efi
+		if [ -f "/boot/$memtest" ]; then
+			echo "Adding $memtest .."
+			cp "/boot/$memtest" "$esp_mp/"
+		fi
 		if [ -n "$mode" ] && [ "$mode" = "grub" ]; then
 			echo "Installing grub x86_64 target.."
 			grub-install.real \
@@ -196,8 +202,23 @@ init_bootloader() {
 			echo "timeout 3" > "$esp_mp/$PMX_LOADER_CONF.tmp"
 			echo "default proxmox-*" >> "$esp_mp/$PMX_LOADER_CONF.tmp"
 			mv "$esp_mp/$PMX_LOADER_CONF.tmp" "$esp_mp/$PMX_LOADER_CONF"
+			memtest_conf="$esp_mp/loader/entries/$memtest.conf"
+			if [ -f "/boot/$memtest" ]; then
+				echo "Adding $memtest .."
+				cp "/boot/$memtest" "$esp_mp/EFI/"
+				cat > "$memtest_conf.tmp" <<- EOF
+					title Memory test ($memtest)
+					efi   /EFI/$memtest
+				EOF
+				mv "$memtest_conf.tmp" "$memtest_conf"
+			fi
 		fi
 	else
+		memtest=memtest86+x64.bin
+		if [ -f "/boot/$memtest" ]; then
+			echo "Adding $memtest .."
+			cp "/boot/$memtest" "$esp_mp/"
+		fi
 		echo "Installing grub i386-pc target.."
 		grub-install.real \
 			--boot-directory "$esp_mp" \
-- 
2.47.3