Fix broken support for Ventoy on UEFI computers

Changes in Slackware-current in March and May 2023 broke support for
detection of Ventoy disk on UEFI computers.
Liveslak's initrd needed to have efivarfs module added, so that
/sys/firmware/efi/efivars can be mounted by the live init script.
With kernel 6.x the content of what's found under efivars
has changed - instead of being represented as a directory with the
efi datastructures as files, liveslak now needs to deal with
a single file instead and find the offset in there.

3 files changed, 14 insertions, 2 deletions

diff --git a/liveinit.tpl b/liveinit.tpl
index 5d34592..44d6c1d 100644
--- a/liveinit.tpl
+++ b/liveinit.tpl
@@ -168,6 +168,11 @@ if grep devtmpfs /proc/filesystems 1>/dev/null 2>/dev/null ; then
   mount -n devtmpfs /dev -t devtmpfs -o size=8M
 fi	
 
+# Mount if this directory exists (so the kernel supports efivarfs):
+if [ -d /sys/firmware/efi/efivars ]; then
+  mount -o rw -t efivarfs none /sys/firmware/efi/efivars
+fi
+
 # Parse command line
 for ARG in $(cat /proc/cmdline); do
   case $ARG in
@@ -818,16 +823,23 @@ if [ "$RESCUE" = "" ]; then
   VENTID="VentoyOsParam-77772020-2e77-6576-6e74-6f792e6e6574"
   VENTVAR="/sys/firmware/efi/vars/${VENTID}"
   if [ ! -d "${VENTVAR}" ]; then
+    # Newer Slackware will use 'efivars' rather than 'vars' directory;
     VENTVAR="/sys/firmware/efi/efivars/${VENTID}"
   fi
   if [ -d "${VENTVAR}" ]; then
     echo "${MARKER}:  (UEFI) Ventoy ISO boot detected..."
     ISOBOOT="ventoy"
     VENTOSPARM="${VENTVAR}/data"
+  elif [ -f "${VENTVAR}" ]; then
+    # Kernel >= 6.x does not offer a clean data sctructure, so we need to
+    # find the offset of the data block in the efivars file:
+    cat "${VENTVAR}" > /vent.dmp
   else
     # Detect Ventoy in memory (don't use the provided hooks), see
     # https://www.ventoy.net/en/doc_compatible_format.html:
     dd if=/dev/mem of=/vent.dmp bs=1 skip=$((0x80000)) count=$((0xA0000-0x80000)) 2>/dev/null
+  fi
+  if [ -f /vent.dmp ]; then
     # Use 'strings' to find the decimal offset of the magic string;
     # With 'xargs' we remove leading and ending spaces:
     if strings -t d /vent.dmp 1>/dev/null 2>/dev/null ; then
diff --git a/make_slackware_live.sh b/make_slackware_live.sh
index c55fc05..e380938 100755
--- a/make_slackware_live.sh
+++ b/make_slackware_live.sh
@@ -255,7 +255,7 @@ TESTINGLIST_DAW=""
 # List of kernel modules required for a live medium to boot properly;
 # Lots of HID modules added to support keyboard input for LUKS password entry;
 # Virtio modules added to experiment with liveslak in a VM.
-KMODS=${KMODS:-"squashfs:overlay:loop:xhci-pci:ohci-pci:ehci-pci:xhci-hcd:uhci-hcd:ehci-hcd:mmc-core:mmc-block:sdhci:sdhci-pci:sdhci-acpi:rtsx_pci:rtsx_pci_sdmmc:usb-storage:uas:hid:usbhid:i2c-hid:hid-generic:hid-apple:hid-cherry:hid-logitech:hid-logitech-dj:hid-logitech-hidpp:hid-lenovo:hid-microsoft:hid_multitouch:jbd:mbcache:ext3:ext4:isofs:fat:nls_cp437:nls_iso8859-1:msdos:vfat:exfat:ntfs:virtio_ring:virtio:virtio_blk:virtio_balloon:virtio_pci:virtio_pci_modern_dev:virtio_net"}
+KMODS=${KMODS:-"squashfs:overlay:loop:efivarfs:xhci-pci:ohci-pci:ehci-pci:xhci-hcd:uhci-hcd:ehci-hcd:mmc-core:mmc-block:sdhci:sdhci-pci:sdhci-acpi:rtsx_pci:rtsx_pci_sdmmc:usb-storage:uas:hid:usbhid:i2c-hid:hid-generic:hid-apple:hid-cherry:hid-logitech:hid-logitech-dj:hid-logitech-hidpp:hid-lenovo:hid-microsoft:hid_multitouch:jbd:mbcache:ext3:ext4:isofs:fat:nls_cp437:nls_iso8859-1:msdos:vfat:exfat:ntfs:virtio_ring:virtio:virtio_blk:virtio_balloon:virtio_pci:virtio_pci_modern_dev:virtio_net"}
 
 # Network kernel modules to include for NFS root support:
 NETMODS="kernel/drivers/net kernel/drivers/virtio"
diff --git a/upslak.sh b/upslak.sh
index b098199..cacc158 100644
--- a/upslak.sh
+++ b/upslak.sh
@@ -133,7 +133,7 @@ COMPR="xz --check=crc32"
 # List of kernel modules required for a live medium to boot properly;
 # Lots of HID modules added to support keyboard input for LUKS password entry;
 # Virtio modules added to experiment with liveslak in a VM.
-KMODS=${KMODS:-"squashfs:overlay:loop:xhci-pci:ohci-pci:ehci-pci:xhci-hcd:uhci-hcd:ehci-hcd:mmc-core:mmc-block:sdhci:sdhci-pci:sdhci-acpi:rtsx_pci:rtsx_pci_sdmmc:usb-storage:uas:hid:usbhid:i2c-hid:hid-generic:hid-apple:hid-cherry:hid-logitech:hid-logitech-dj:hid-logitech-hidpp:hid-lenovo:hid-microsoft:hid_multitouch:jbd:mbcache:ext3:ext4:isofs:fat:nls_cp437:nls_iso8859-1:msdos:vfat:exfat:ntfs:virtio_ring:virtio:virtio_blk:virtio_balloon:virtio_pci:virtio_pci_modern_dev:virtio_net"}
+KMODS=${KMODS:-"squashfs:overlay:loop:efivarfs:xhci-pci:ohci-pci:ehci-pci:xhci-hcd:uhci-hcd:ehci-hcd:mmc-core:mmc-block:sdhci:sdhci-pci:sdhci-acpi:rtsx_pci:rtsx_pci_sdmmc:usb-storage:uas:hid:usbhid:i2c-hid:hid-generic:hid-apple:hid-cherry:hid-logitech:hid-logitech-dj:hid-logitech-hidpp:hid-lenovo:hid-microsoft:hid_multitouch:jbd:mbcache:ext3:ext4:isofs:fat:nls_cp437:nls_iso8859-1:msdos:vfat:exfat:ntfs:virtio_ring:virtio:virtio_blk:virtio_balloon:virtio_pci:virtio_pci_modern_dev:virtio_net"}
 
 # Network kernel modules to include for NFS root support:
 NETMODS="kernel/drivers/net kernel/drivers/virtio"