{ pkgs
, lib
, sources
, ... }:

let
  mkArmTrustedFirmwareBpiR3 = { bootDevice, uboot ? null }: pkgs.buildArmTrustedFirmware rec {
    inherit (sources.atf-bpir3) src;
    patches = [ ./bpi-r3-atf-backport-mkimage-support.patch ];
    extraMakeFlags = assert builtins.elem bootDevice [
      "nor" "snand" "spim-nand" "emmc" "sdmmc" "ram"
    ]; [
      "BOOT_DEVICE=${bootDevice}"
      "DRAM_USE_DDR4=1"
      "USE_MKIMAGE=1"
      "MKIMAGE=${pkgs.ubootTools}/bin/mkimage"
      "all"
      "fip"
    ] ++ lib.optionals (uboot != null) [
      "BL33=${uboot}/u-boot.bin"
    ];
    extraMeta.platforms = [ "aarch64-linux" ];
    platform = "mt7986";
    filesToInstall = [
      "build/${platform}/release/bl2.img"
      "build/${platform}/release/fip.bin"
    ];
    nativeBuildInputs = with pkgs; [ /*pkgsCross.arm-embedded.stdenv.cc*/ dtc ];
  };
  # sd/emmc
  # -- CONFIG_USE_BOOTCOMMAND/CONFIG_BOOTCOMMAND - distroboot stuff (override default boot command)
  # -- CONFIG_BOOTDELAY - autoboot timeout
  # CONFIG_BOOTSTD_DEFAULTS - stdboot stuff
  # CONFIG_BOOTSTD_BOOTCOMMAND - might be? an alternative to CONFIG_BOOTCOMMAND
  # CONFIG_DEFAULT_FDT_FILE - compatibility with nixos
  # CONFIG_DISTRO_DEFAULTS - surely this won't hurt, it adds autocomplete and stuff and doesn't weight much in the large scale of things
  # CONFIG_SYS_BOOTM_LEN - increase max initrd? size
  # CONFIG_ZSTD - allow zstd initrd
  mkUbootConfig = storage: ''
    CONFIG_AUTOBOOT=y
    CONFIG_BOOTCOMMAND="${builtins.replaceStrings [ "\n" ] [ "; " ] ''
        setenv boot_prefixes /@boot/ /@/ /boot/ /
        run distro_bootcmd
    ''};"
    CONFIG_BOOTSTD_DEFAULTS=y
    CONFIG_BOOTSTD_FULL=y
    CONFIG_CMD_BTRFS=y
    CONFIG_CMD_CAT=y
    CONFIG_DEFAULT_FDT_FILE="mediatek/mt7986a-bananapi-bpi-r3.dtb"
    CONFIG_DISTRO_DEFAULTS=y
    CONFIG_ENV_IS_NOWHERE=y
    CONFIG_FS_BTRFS=y
    CONFIG_SYS_BOOTM_LEN=0x6000000
    CONFIG_USE_BOOTCOMMAND=y
    CONFIG_ZSTD=y
  '';
  ubootVersion = "2023.07-rc4";
  ubootSrc = pkgs.fetchurl {
    url = "ftp://ftp.denx.de/pub/u-boot/u-boot-${ubootVersion}.tar.bz2";
    hash = "sha256-tqp9fnGPQFeNGrkU/A6AusDEz7neh2KiR9HWbR7+WTY=";
  };

in rec {
  sd.uboot = pkgs.buildUBoot {
    defconfig = "mt7986a_bpir3_sd_defconfig";
    extraConfig = mkUbootConfig "sd";
    src = ubootSrc;
    version = ubootVersion;
    extraMeta.platforms = [ "aarch64-linux" ];
    # https://github.com/nakato/nixos-bpir3-example/blob/main/pkgs/uboot/mt7986-default-bootcmd.patch
    patches = [ ./mt7986-default-bootcmd.patch ];
    filesToInstall = [ "u-boot.bin" ];
  };
  emmc.uboot = pkgs.buildUBoot {
    defconfig = "mt7986a_bpir3_emmc_defconfig";
    extraConfig = mkUbootConfig "emmc";
    src = ubootSrc;
    version = ubootVersion;
    extraMeta.platforms = [ "aarch64-linux" ];
    patches = [ ./mt7986-default-bootcmd.patch ];
    filesToInstall = [ "u-boot.bin" ];
  };
  sd.armTrustedFirmware = mkArmTrustedFirmwareBpiR3 { inherit (sd) uboot; bootDevice = "sdmmc"; };
  emmc.armTrustedFirmware = mkArmTrustedFirmwareBpiR3 { inherit (emmc) uboot; bootDevice = "emmc"; };
  combinedStuff = pkgs.stdenvNoCC.mkDerivation {
    name = "bpi-r3-stuff";
    unpackPhase = "true";
    buildPhase = "true";
    installPhase = ''
      mkdir -p $out/sd
      mkdir -p $out/emmc
      cp ${emmc.stuff}/* $out/emmc
      cp ${sd.stuff}/* $out/sd
    '';
    fixupPhase = "true";
  };
  emmc.stuff = pkgs.stdenvNoCC.mkDerivation {
    name = "bpi-r3-stuff-emmc";
    unpackPhase = "true";
    buildPhase = "true";
    installPhase = ''
      mkdir -p $out
      cp ${emmc.uboot}/*.* $out
      cp ${emmc.armTrustedFirmware}/*.* $out
    '';
    fixupPhase = "true";
  };
  sd.stuff = pkgs.stdenvNoCC.mkDerivation {
    name = "bpi-r3-stuff-sd";
    unpackPhase = "true";
    buildPhase = "true";
    installPhase = ''
      mkdir -p $out
      cp ${sd.uboot}/*.* $out
      cp ${sd.armTrustedFirmware}/*.* $out
    '';
    fixupPhase = "true";
  };
  linux = pkgs.linux_latest.override {
    ignoreConfigErrors = false;
    # there's probably more enabled-by-default configs that are better left disabled, but whatever
    structuredExtraConfig = with lib.kernel; {
      /* "Select this option if you are building a kernel for a server or
          scientific/computation system, or if you want to maximize the
          raw processing power of the kernel, irrespective of scheduling
          latencies." */
      PREEMPT_NONE = yes;
      # disable the other preempts
      PREEMPT_VOLUNTARY = lib.mkForce no;
      PREEMPT = no;

      CPU_FREQ_GOV_ONDEMAND = yes;
      CPU_FREQ_DEFAULT_GOV_ONDEMAND = yes;
      CPU_FREQ_DEFAULT_GOV_SCHEDUTIL = lib.mkForce no;
      CPU_FREQ_DEFAULT_GOV_PERFORMANCE = lib.mkForce no;
      CPU_FREQ_GOV_CONSERVATIVE = yes;
      # disable virtualisation stuff
      VIRTUALIZATION = no;
      XEN = lib.mkForce no;
      # zstd
      # MODULE_COMPRESS_ZSTD = yes;
      MODULE_DECOMPRESS = yes;
      FW_LOADER_COMPRESS_ZSTD = yes;
      # zram
      ZRAM_DEF_COMP_ZSTD = yes;
      CRYPTO_ZSTD = yes;
      ZRAM_MEMORY_TRACKING = yes;
      # router stuff
      IP_FIB_TRIE_STATS = yes;
      IP_ROUTE_CLASSID = yes;
      # adds sysctl net.ipv4.tcp_syncookies
      SYN_COOKIES = yes;
      WIREGUARD = yes;
      INET = yes;
      # stuff for ss
      NETLINK_DIAG = yes;
      # nftables features
      IP_SET = module;
      NF_CONNTRACK = module;
      NF_CONNTRACK_BRIDGE = module;
      NF_CONNTRACK_MARK = yes;
      NF_NAT = module;
      NF_FLOW_TABLE = module;
      NF_FLOW_TABLE_INET = module;
      NF_LOG_ARP = module;
      NF_LOG_IPV4 = module;
      NF_LOG_IPV6 = module;
      NETFILTER_NETLINK_QUEUE = module;
      NFT_BRIDGE_META = module;
      NFT_BRIDGE_REJECT = module;
      NFT_CONNLIMIT = module;
      NFT_CT = module;
      NFT_DUP_IPV4 = module;
      NFT_DUP_IPV6 = module;
      NFT_DUP_NETDEV = module;
      NFT_FIB = module;
      NFT_FIB_IPV4 = module;
      NFT_FIB_IPV6 = module;
      NFT_FIB_INET = module;
      NFT_FIB_NETDEV = module;
      NFT_FLOW_OFFLOAD = module;
      NFT_FWD_NETDEV = module;
      NFT_HASH = module;
      NFT_LIMIT = module;
      NFT_LOG = module;
      NFT_MASQ = module;
      NFT_NAT = module;
      NFT_NUMGEN = module;
      NFT_OSF = module;
      NFT_QUEUE = module;
      NFT_QUOTA = module;
      NFT_REDIR = module;
      NFT_REJECT = module;
      NFT_REJECT_IPV4 = module;
      NFT_REJECT_IPV6 = module;
      NFT_REJECT_INET = module;
      NFT_SOCKET = module;
      NFT_SYNPROXY = module;
      NFT_TPROXY = module;
      NFT_TUNNEL = module;

      BRIDGE = yes;
      HSR = no;
      NET_DSA = yes;

      # packet CLaSsification
      NET_CLS_ROUTE4 = module;
      NET_CLS_FW = module;
      NET_CLS_U32 = module;
      NET_CLS_FLOW = module;
      NET_CLS_CGROUP = module;
      NET_CLS_FLOWER = module;
      NET_CLS_MATCHALL = module;
      NET_EMATCH = yes;
      NET_EMATCH_CMP = module;
      NET_EMATCH_NBYTE = module;
      NET_EMATCH_U32 = module;
      NET_EMATCH_META = module;
      NET_EMATCH_TEXT = module;
      NET_EMATCH_IPSET = module;

      # packet actions
      NET_CLS_ACT = yes;
      NET_ACT_POLICE = module;
      NET_ACT_GACT = module;
      NET_ACT_SAMPLE = module;
      NET_ACT_NAT = module;
      NET_ACT_PEDIT = module;
      NET_ACT_SKBEDIT = module;
      NET_ACT_CSUM = module;
      NET_ACT_MPLS = module;
      NET_ACT_VLAN = module;
      NET_ACT_CONNMARK = module;
      NET_ACT_CTINFO = module;
      NET_ACT_SKBMOD = module;
      NET_ACT_IFE = module;
      NET_ACT_TUNNEL_KEY = module;
      NET_ACT_CT = module;

      # random stuff
      PSAMPLE = module;
      RFKILL = yes;
      CRYPTO_SHA256 = yes;

      # hardware specific stuff
      FB = lib.mkForce no;
      DRM = lib.mkForce no;
      SOUND = no;
      INFINIBAND = lib.mkForce no;
      CFG80211 = module;
      MAC80211 = module;
      WLAN = yes;

      NR_CPUS = lib.mkForce (freeform "4");
      SMP = yes;

      SFP = yes;
      ARCH_MEDIATEK = yes;
      COMMON_CLK_MEDIATEK = yes;
      COMMON_CLK_MEDIATEK_FHCTL = yes;
      COMMON_CLK_MT7986 = yes;
      COMMON_CLK_MT7986_ETHSYS = yes;
      CPU_THERMAL = yes;
      THERMAL_OF = yes;
      EINT_MTK = yes;
      MEDIATEK_GE_PHY = yes;
      MEDIATEK_WATCHDOG = yes;
      MTD_NAND_ECC_MEDIATEK = yes;
      MTD_NAND_ECC_SW_HAMMING = yes;
      MTD_NAND_MTK = yes;
      MTD_SPI_NAND = yes;
      MTD_UBI = yes;
      MTD_UBI_BLOCK = yes;
      NVMEM_MTK_EFUSE = yes;
      MTK_HSDMA = yes;
      MTK_INFRACFG = yes;
      MTK_PMIC_WRAP = yes;
      MTK_LVTS_THERMAL = yes;
      MTK_SOC_THERMAL = yes;
      MTK_THERMAL = yes;
      MTK_TIMER = yes;
      NET_DSA_MT7530 = yes;
      NET_DSA_MT7530_MDIO = yes;
      NET_DSA_MT7530_MMIO = yes;
      NET_DSA_TAG_MTK = yes;
      NET_MEDIATEK_SOC = yes;
      NET_MEDIATEK_SOC_WED = yes;
      NET_MEDIATEK_STAR_EMAC = yes;
      NET_SWITCHDEV = yes;
      NET_VENDOR_MEDIATEK = yes;
      PCIE_MEDIATEK = yes;
      PCIE_MEDIATEK_GEN3 = yes;
      PCS_MTK_LYNXI = yes;
      PINCTRL_MTK = yes;
      PINCTRL_MT7986 = yes;
      PWM_MEDIATEK = yes;
      REGULATOR_MT6380 = yes;
      MT76_CORE  = module;
      MT76_LEDS = yes;
      MT76_CONNAC_LIB = module;
      MT7915E = module;
      MT798X_WMAC = yes;
      SPI_MT65XX = yes;
      SPI_MTK_NOR = yes;
      SPI_MTK_SNFI = yes;
      MMC_MTK = yes;

      # keys that are unused in this case
      # used because i got bitten by config keys changing once
      SND_AC97_POWER_SAVE_DEFAULT.optional = lib.mkForce true; SND_HDA_POWER_SAVE_DEFAULT.optional = lib.mkForce true;
      SND_USB_AUDIO_MIDI_V2.tristate = lib.mkForce null; SND_HDA_CODEC_CS8409.tristate = lib.mkForce null;
      DRM_DISPLAY_DP_AUX_CEC.tristate = lib.mkForce null; DRM_DISPLAY_DP_AUX_CHARDEV.tristate = lib.mkForce null;
      DRM_ACCEL.tristate = lib.mkForce null; DRM_AMD_ACP.tristate = lib.mkForce null; DRM_AMD_SECURE_DISPLAY.tristate = lib.mkForce null;
      DRM_DP_CEC.tristate = lib.mkForce null; DRM_NOUVEAU_SVM.tristate = lib.mkForce null; MEM_SOFT_DIRTY.tristate = lib.mkForce null;
      PM_TRACE.tristate = lib.mkForce null; RAS_CEC.tristate = lib.mkForce null; SND_AC97_POWER_SAVE_DEFAULT.tristate = lib.mkForce null;
      AGP.tristate = lib.mkForce null; ACPI_HOTPLUG_CPU.tristate = lib.mkForce null; CEPH_FSCACHE.tristate = lib.mkForce null;
      CIFS_FSCACHE.tristate = lib.mkForce null; DRM_NOUVEAU_GSP_DEFAULT.tristate = lib.mkForce null; FSCACHE_STATS.tristate = lib.mkForce null;
      "9P_FSCACHE".tristate = lib.mkForce null; CROS_EC_ISHTP.tristate = lib.mkForce null; CROS_EC_LPC.tristate = lib.mkForce null;
      DRM_AMDGPU_CIK.tristate = lib.mkForce null; DRM_AMDGPU_SI.tristate = lib.mkForce null; DRM_AMDGPU_USERPTR.tristate = lib.mkForce null;
      DRM_AMD_DC_FP.tristate = lib.mkForce null; DRM_AMD_DC_SI.tristate = lib.mkForce null; DRM_DP_AUX_CHARDEV.tristate = lib.mkForce null;
      DRM_FBDEV_EMULATION.tristate = lib.mkForce null; DRM_GMA500.tristate = lib.mkForce null; DRM_LEGACY.tristate = lib.mkForce null;
      DRM_LOAD_EDID_FIRMWARE.tristate = lib.mkForce null; DRM_SIMPLEDRM.tristate = lib.mkForce null; DRM_VBOXVIDEO.tristate = lib.mkForce null;
      DRM_VC4_HDMI_CEC.tristate = lib.mkForce null; FB_3DFX_ACCEL.tristate = lib.mkForce null; FB_ATY_CT.tristate = lib.mkForce null;
      FB_ATY_GX.tristate = lib.mkForce null; FB_EFI.tristate = lib.mkForce null; FB_NVIDIA_I2C.tristate = lib.mkForce null;
      FB_RIVA_I2C.tristate = lib.mkForce null; FB_SAVAGE_ACCEL.tristate = lib.mkForce null; FB_SAVAGE_I2C.tristate = lib.mkForce null;
      FB_SIMPLE.tristate = lib.mkForce null; FB_SIS_300.tristate = lib.mkForce null; FB_SIS_315.tristate = lib.mkForce null;
      FB_VESA.tristate = lib.mkForce null; FONTS.tristate = lib.mkForce null; FONT_8x8.tristate = lib.mkForce null;
      FONT_TER16x32.tristate = lib.mkForce null; FRAMEBUFFER_CONSOLE.tristate = lib.mkForce null;
      FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER.tristate = lib.mkForce null;
      FRAMEBUFFER_CONSOLE_DETECT_PRIMARY.tristate = lib.mkForce null; FRAMEBUFFER_CONSOLE_ROTATION.tristate = lib.mkForce null;
      HMM_MIRROR.tristate = lib.mkForce null; HSA_AMD.tristate = lib.mkForce null; HYPERVISOR_GUEST.tristate = lib.mkForce null;
      INFINIBAND_IPOIB.tristate = lib.mkForce null; INFINIBAND_IPOIB_CM.tristate = lib.mkForce null;
      IP_MROUTE_MULTIPLE_TABLES.tristate = lib.mkForce null; JOYSTICK_PSXPAD_SPI_FF.tristate = lib.mkForce null;
      KERNEL_ZSTD.tristate = lib.mkForce null; KEYBOARD_APPLESPI.tristate = lib.mkForce null; KVM_ASYNC_PF.tristate = lib.mkForce null;
      KVM_GENERIC_DIRTYLOG_READ_PROTECT.tristate = lib.mkForce null; KVM_GUEST.tristate = lib.mkForce null; KVM_MMIO.tristate = lib.mkForce null;
      KVM_VFIO.tristate = lib.mkForce null; LOGO.tristate = lib.mkForce null; MICROCODE.tristate = lib.mkForce null;
      MOUSE_PS2_VMMOUSE.tristate = lib.mkForce null; MTRR_SANITIZER.tristate = lib.mkForce null; NFS_FSCACHE.tristate = lib.mkForce null;
      PINCTRL_BAYTRAIL.tristate = lib.mkForce null;
      PINCTRL_CHERRYVIEW.tristate = lib.mkForce null; PM_ADVANCED_DEBUG.tristate = lib.mkForce null; PM_TRACE_RTC.tristate = lib.mkForce null;
      SND_AC97_POWER_SAVE.tristate = lib.mkForce null; SND_DYNAMIC_MINORS.tristate = lib.mkForce null;
      SND_HDA_INPUT_BEEP.tristate = lib.mkForce null; SND_HDA_PATCH_LOADER.tristate = lib.mkForce null;
      SND_HDA_RECONFIG.tristate = lib.mkForce null; SND_OSSEMUL.tristate = lib.mkForce null; SND_USB_CAIAQ_INPUT.tristate = lib.mkForce null;
      VFIO_PCI_VGA.tristate = lib.mkForce null; VGA_SWITCHEROO.tristate = lib.mkForce null; X86_AMD_PLATFORM_DEVICE.tristate = lib.mkForce null;
      X86_CHECK_BIOS_CORRUPTION.tristate = lib.mkForce null; X86_MCE.tristate = lib.mkForce null;
      X86_PLATFORM_DRIVERS_DELL.tristate = lib.mkForce null; X86_PLATFORM_DRIVERS_HP.tristate = lib.mkForce null;
      JOYSTICK_XPAD_FF.tristate = lib.mkForce null; JOYSTICK_XPAD_LEDS.tristate = lib.mkForce null; KEXEC_JUMP.tristate = lib.mkForce null;
      PERF_EVENTS_AMD_BRS.tristate = lib.mkForce null; HVC_XEN.tristate = lib.mkForce null; HVC_XEN_FRONTEND.tristate = lib.mkForce null;
      PARAVIRT_SPINLOCKS.tristate = lib.mkForce null; PCI_XEN.tristate = lib.mkForce null; SWIOTLB_XEN.tristate = lib.mkForce null;
      VBOXGUEST.tristate = lib.mkForce null; XEN_BACKEND.tristate = lib.mkForce null; XEN_BALLOON.tristate = lib.mkForce null;
      XEN_BALLOON_MEMORY_HOTPLUG.tristate = lib.mkForce null; XEN_DOM0.tristate = lib.mkForce null; XEN_EFI.tristate = lib.mkForce null;
      XEN_HAVE_PVMMU.tristate = lib.mkForce null; XEN_MCE_LOG.tristate = lib.mkForce null; XEN_PVH.tristate = lib.mkForce null;
      XEN_PVHVM.tristate = lib.mkForce null; XEN_SAVE_RESTORE.tristate = lib.mkForce null; XEN_SYS_HYPERVISOR.tristate = lib.mkForce null;
    };
  };
  linuxPackages = pkgs.linuxPackagesFor linux;
}