;;; Nonguix `linux' with the options a Raspberry Pi 4 needs to boot from
;;; microSD and bring up its onboard Ethernet.
;;;
;;; The stock config ships CLK_BCM2835 disabled (emmc2's clock comes from the
;;; cprman, so the SD card never probes), MMC/regulator/firmware-GPIO bits as
;;; modules (the SD regulators hang off the firmware GPIO expander), and no
;;; GENET Ethernet at all.  Everything on the path to the root file system is
;;; built in so the initrd needs no Pi-specific modules.
(define-module (rpi4-linux)
  #:use-module (gnu packages linux)
  #:use-module (guix packages)
  #:use-module (nongnu packages linux)
  #:export (linux-rpi4))

(define %rpi4-kernel-configs
  '(;; SD card (emmc2): clocks, regulators, controller, block device.
    "CONFIG_CLK_BCM2835=y"
    "CONFIG_CLK_RASPBERRYPI=y"
    "CONFIG_GPIO_RASPBERRYPI_EXP=y"
    "CONFIG_REGULATOR_FIXED_VOLTAGE=y"
    "CONFIG_REGULATOR_GPIO=y"
    "CONFIG_MMC_SDHCI=y"
    "CONFIG_MMC_SDHCI_PLTFM=y"
    "CONFIG_MMC_SDHCI_IPROC=y"
    "CONFIG_RPMB=y"                    ;MMC_BLOCK depends on RPMB || !RPMB
    "CONFIG_MMC_BLOCK=y"
    ;; VL805 USB 3 controller needs its firmware loaded via the reset driver.
    "CONFIG_RESET_RASPBERRYPI=y"
    ;; Onboard Gigabit Ethernet (BCM54213PE behind GENET).
    "CONFIG_BCMGENET=m"
    "CONFIG_MDIO_BCM_UNIMAC=m"
    "CONFIG_BROADCOM_PHY=m"))

(define-public linux-rpi4
  (customize-linux #:name "linux-rpi4"
                   #:linux linux
                   #:configs %rpi4-kernel-configs))