################################################################################ # Helper script: /load_kernel_modules.scr/platform/aarch64/bcm2711 # Purpose......: Set the Kernel modules for Hardware Models that use the BCM2711 # SoC within the Slackware initial RAM disk ('OS initrd') # and the Slackware installer. # Currently supported Hardware Models: # * Raspberry Pi 4 # This script is sourced from '/load_kernel_modules' # Author.......: Stuart Winter # Date.........: 30-Mar-2021 # Maintainer...: Stuart Winter, Brent Earl. # # Please use this as an reference and example of how to add support for # a new Hardware Model to Slackware ARM/AArch64. # # Important Note: # * You must _append_ to the module lists (include the variable # name within the variable itself), otherwise the base # set of modules will not be loaded and would result in # a Kernel panic. # * The initrd uses the 'bash' shell, rather than 'busybox' # (as in upstream/x86 Slackware). This allows you (for example) # to use 'fallthrough' (case statements terminated with ';&' # rather than ';;') within case statements and regular expression # matches within 'if' statements. # This permits the 'c'-style switch statements where you can # 'inherit' the previous matches as you move down the cases. # This enables you to match on varients of boards, and inherit # a 'baseline' of platform modules for that board. # # The 'PLATWALK' match is to enable build scripts to process these # scripts outside of the initrd environment and determine which # modules will be loaded by a particular Hardware Model. This must remain # in place for all scripts. ################################################################################ case $HWM in "Raspberry Pi 4"*|PLATWALK) platform_detected=1 SOC_NAME=bcm2711 # Set the short name that is used by /load_kernel_modules to install # the appropriate configuration for modprobe for this Hardware Model: HWM_SHORTNAME=rpi4 echo "Architecture: ${ARCH}, Hardware model: ${HWM}, SoC: ${SOC_NAME}" # If one of the modules within the base list is causing problems on # your platform, here are the options laid out as examples: # USB="${USB/ehci_orion/differentmodule}" # Substitute module 'ehci_orion' with 'differentmodule' # USB="${USB/ehci_orion/}" # Remove the 'ehci_orion' module from the list MOD_GPIO+=" " MOD_PHY+=" bcm_phy_lib phy_generic" MOD_VIDEO+=" simpledrm v3d" # sdhci-iproc caused crash in 5.19 taking down the SD subsystem: # Seems to work in 6.1. MOD_CARDS+=" sdhci-iproc" MOD_USB+=" dwc2 dwc3" MOD_NET+=" " MOD_CMP+=" " MOD_CRYPTO+=" " # Example to detect hardware at runtime: #{ lspci 2>/dev/null | grep -q 'SATA cont.*ATA' ;} && MOD_XX="$MOD_XX yyy" # The following modules do not inherit: MOD_RTC="rtc-ds1307 rtc-pcf8523" # Modules for the peripherals on the Hardware Model's main board # (outside of the SoC itself) # Note: the distinction between the SoC and HWM is blurred presently # This needs organising according to the hardware - TODO! MOD_HWM="pcie_brcmstb mdio_bcm_unimac simple-pm-bus iproc_rng200 pwrseq_simple crct10dif_ce" # Modules for the IP blocks/peripherals embedded within the SoC: MOD_SOC="broadcom clk_raspberrypi pwm-bcm2835 raspberrypi-hwmon i2c-bcm2835 i2c_brcmstb" # /load_kernel_modules provides the ability to run a defined function # just prior to loading the Linux Kernel module lists that have been # defined in the base set + directly above these lines. # There's no current use case for this - it's here to expose it as # an option should it be useful at some future time. #function hwm_hook_pre-modload() { #} # # And the same functionality once the Kernel modules have been loaded. # This allows us to set up the RTC, which we cannot do at the time this # script is loaded initially, as the RTC device is only addressable upon # having loaded the driver into the Kernel. # To achieve this effect locally, users should look at # /boot/local/README.txt # and create /boot/local/load_kernel_modules.post from the sample file. # This is a shell script in which you can 'modprobe' additional modules, # and run shell code as we do below to write a value into the RTC's # Kernel interface to initialise it. # # This function is here because this particular RTC is officially # supported by Slackware AArch64, as it's connected to this author's # RPi4. # function hwm_hook_post-modload() { # Initialise a DS1307 RTC without Device Tree Overlay. # # When booting Slackware directly from the RPi's native Boot Loader, # we add a Kernel command line operator 'slkrpinbl' which enables # these types of conditional actions: grep -iq "slkrpinbl" /proc/cmdline 2> /dev/null || { # Silently detect peripherals on bus 1. # Something like this, self-contained would be ideal: #sensors-detect --auto > /dev/null 2>&1 i2cdetect -y 1 > /dev/null 2>&1 # Unless you change this setting, it'll appear as position 68. [ -f /sys/class/i2c-adapter/i2c-1/new_device ] && \ echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device } } # Define a function to run from the OS InitRD's '/init' immediately prior # to switching into the Slackware OS proper. # This is after any software RAID arrays et al have been initialised. # There's no current use case for this, but it may be useful in the future. # # At this stage, the following paths for Slackware OS are mounted: # /proc, /sys, /run, /dev # The root file system ('/') is mounted under /mnt # #function hwm_hook_pre_switch_root() { # echo "Just about to switch into the Slackware OS proper, leaving the OS InitRD" # sleep 4 #} # End of stanza - the ';;' below must be the last line: ;; esac # The '/load_kernel_modules' script will load the modules # set above.