### Slackware Installer script #############################################################################
# Script......: /usr/share/hwm-configure/platform/aarch64/installer/helper.scr/999-rpi-kernel-fork-configure
# Called from : /usr/lib/setup/armedslack-postinstall-scripts/001-hwm-os-configure
#               This is 'sourced' from that helper script, hence we use 'return' rather than 'exit'
#               statements. If necessary in the future, we can have it 'forked' by including the special
#               token.
# Purpose.....: Operating System configuration helper for the Raspberry Pi.
#               This configures the OS in line with the requirements of the RPi Kernel fork, and is used
#               only when by the RPi Slackware Installer variant.
# Author......: Stuart Winter <mozes@slackware.com>
# Date........: 08-Nov-2025
### Slackware Installer script ############################################################################
# Note: There is some duplication between this script and one of those included in the original Installer
# /usr/share/hwm-configure/platform/aarch64/installer/helper.scr/999-rpi-vendor-kernel-transition
# This is because the official AiO Installers are capable of transitioning to the RPi Kernel fork directly
# thus need to make the same adjustments. However, that script also upgradepkg's to the RPi Kernel fork
# packages upon user request, where as with SAIR (this script) we're booting and bundling the RPi Kernel
# fork packages are the primary Kernel.
# Neither of these helper scripts interfers with the other, as the other script exits if it finds our
# feature flag file.

# Only launch if this feature flag file exists within the Installer:
[ ! -f /.is-rpi-kernel-fork ] && return 0

# Determine the Hardware Model name:
export HWM=$( slk-hwm-discover )
# Determine archtecture:
ARCH=$( slk-hwm-discover --print-arch )

# Quit silently if we're not running on a Raspberry Pi.
# At some point we might need to differentiate between RPi models, but for the moment
# the settings apply to all variants.
[[ "$HWM" != "Raspberry Pi"* ]] && return 0

# The newly installed OS' /etc/inittab:
inittabfile=${T_PX}/etc/inittab

# U-Boot Boot Loader configuration file:
uboot_bootloaderconf=${T_PX}/boot/extlinux/extlinux.conf

# slackpkg's blacklist:
slackpkgblacklistfile=${T_PX}/etc/slackpkg/blacklist

# Raspberry Pi Native BL config.txt:
slk_rpi_bl_conf=${T_PX}/boot/platform/hwm_bw/slk_config.txt

# Serial address for Raspberry Pi variants:
case "$HWM" in
   "Raspberry Pi 5"*)
   SERIALDEV=ttyAMA0;;
   # All other variants:
   "Raspberry Pi"*)
   SERIALDEV=ttyS0;;
esac

# Display info so we can identify the changes are being made:
dialog \
   --backtitle "Hardware Model Variant Customizations" \
   --sleep 4 \
   --infobox "\nAdjusting configurations for Raspberry Pi Kernel fork ..." 6 50

# Update serial console settings to align with the RPi Kernel fork's configuration:
#
# U-Boot Boot Loader configuration:
# We no longer use U-Boot on the RPi, so commented.
# This was required for U-Boot, but with the native BL, it doesn't seem necessary..
# It is necessary - we need to switch console=ttyS0 - but this is now performed within
# 002-rpi_bl-configure
#[ -f ${uboot_bootloaderconf} ] && {
#  sed -iE '/^[[:blank:]]*APPEND[[:blank:]]/ s/$/ 8250.nr_uarts=1 console=ttyS0,115200 console=tty1/' ${uboot_bootloaderconf} ;}

# For the Native BL:
# Instruct it that we're not using the mainline 'upstream' Kernel:
# Commented because we don't seem to need this - the Kernel fork works anyway...
#sed -i 's/^upstream_kernel=1/#&/' ${slk_rpi_bl_conf}

# Adjustments of the Linux Kernel cmdline ops are performed within
# /usr/share/hwm-configure/platform/aarch64/installer/helper.scr/003-rpi_bl-configure
# since we're already touching the RPi's 'cmdline.txt', and it's easier to do it there.

# /etc/inittab:
# ttyS1 is set by the 'a/sysvinit-scripts' package's doinst.sh - all RPi's are currently
# configured to set it to ttyS1.
[ -f ${inittabfile} ] && sed -iE '/^s0:12345:/ s/ttyS1/'"${SERIALDEV}"'/' ${inittabfile}

# Black list the regular Slackware Kernel to avoid them replacing the RPi Kernel fork:
if [ -f ${slackpkgblacklistfile} ]; then
cat << EOF >> ${slackpkgblacklistfile}

# Blacklist the official Linux Kernel Slackware packages so that the
# Raspberry Pi Kernel fork packages can remain installed.
kernel_armv8
kernel-source
# The kernel-headers package should not be blacklisted. The official Slackware
# package should remain - there's no need to install an RPi specific version.
#kernel-headers
EOF
fi