nixpkgs/nixos/modules/installer/cd-dvd/sd-image-aarch64.nix
Samuel Dionne-Riel 4e75a31e98 linux: configure aarch64 contiguous memory allocator via kernel config
As per the in-line comment, this is where distros should configure it.
Not via kernel command line parameters.

As found by looking at the implementation, while exploring the cause of
a bug on the Raspberry Pi 4, it was found that `cma=` on the command
line parameters will overwrite the values a device tree will have
configured for a given platform.

With this, the more recent 5.4 vendor kernel boots just fine on the
Raspberry Pi 4 using our common configuration.
2020-12-31 18:20:49 +01:00

81 lines
2.7 KiB
Nix

# To build, use:
# nix-build nixos -I nixos-config=nixos/modules/installer/cd-dvd/sd-image-aarch64.nix -A config.system.build.sdImage
{ config, lib, pkgs, ... }:
{
imports = [
../../profiles/base.nix
../../profiles/installation-device.nix
./sd-image.nix
];
boot.loader.grub.enable = false;
boot.loader.generic-extlinux-compatible.enable = true;
boot.consoleLogLevel = lib.mkDefault 7;
# The serial ports listed here are:
# - ttyS0: for Tegra (Jetson TX1)
# - ttyAMA0: for QEMU's -machine virt
boot.kernelParams = ["console=ttyS0,115200n8" "console=ttyAMA0,115200n8" "console=tty0"];
boot.initrd.availableKernelModules = [
# Allows early (earlier) modesetting for the Raspberry Pi
"vc4" "bcm2835_dma" "i2c_bcm2835"
# Allows early (earlier) modesetting for Allwinner SoCs
"sun4i_drm" "sun8i_drm_hdmi" "sun8i_mixer"
];
sdImage = {
populateFirmwareCommands = let
configTxt = pkgs.writeText "config.txt" ''
[pi3]
kernel=u-boot-rpi3.bin
[pi4]
kernel=u-boot-rpi4.bin
enable_gic=1
armstub=armstub8-gic.bin
# Otherwise the resolution will be weird in most cases, compared to
# what the pi3 firmware does by default.
disable_overscan=1
[all]
# Boot in 64-bit mode.
arm_64bit=1
# U-Boot needs this to work, regardless of whether UART is actually used or not.
# Look in arch/arm/mach-bcm283x/Kconfig in the U-Boot tree to see if this is still
# a requirement in the future.
enable_uart=1
# Prevent the firmware from smashing the framebuffer setup done by the mainline kernel
# when attempting to show low-voltage or overtemperature warnings.
avoid_warnings=1
'';
in ''
(cd ${pkgs.raspberrypifw}/share/raspberrypi/boot && cp bootcode.bin fixup*.dat start*.elf $NIX_BUILD_TOP/firmware/)
# Add the config
cp ${configTxt} firmware/config.txt
# Add pi3 specific files
cp ${pkgs.ubootRaspberryPi3_64bit}/u-boot.bin firmware/u-boot-rpi3.bin
# Add pi4 specific files
cp ${pkgs.ubootRaspberryPi4_64bit}/u-boot.bin firmware/u-boot-rpi4.bin
cp ${pkgs.raspberrypi-armstubs}/armstub8-gic.bin firmware/armstub8-gic.bin
cp ${pkgs.raspberrypifw}/share/raspberrypi/boot/bcm2711-rpi-4-b.dtb firmware/
'';
populateRootCommands = ''
mkdir -p ./files/boot
${config.boot.loader.generic-extlinux-compatible.populateCmd} -c ${config.system.build.toplevel} -d ./files/boot
'';
};
# the installation media is also the installation target,
# so we don't want to provide the installation configuration.nix.
installer.cloneConfig = false;
}