It's been 8.5 years since NixOS used mingetty, but the option was
never renamed (despite the file definining the module being renamed in
9f5051b76c ("Rename mingetty module to agetty")).
I've chosen to rename it to services.getty here, rather than
services.agetty, because getty is implemantation-neutral and also the
name of the unit that is generated.
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.
This includes setting up everything for the mainline Raspberry Pi 4
image.
In fact, the only difference left in the Raspberry Pi 4-specific image
is the kernel from the vendor.
Prior to this commit, installation over serial console would requiring
manually having to modify the kernel modeline, as described in
https://github.com/NixOS/nixpkgs/issues/58198 .
This is unnecessarily fiddly, so this commit adds a syslinux boot
entry that has serial enabled.
GRUB already has a serial console entry:
2c07a0800a/nixos/modules/installer/cd-dvd/iso-image.nix (L311-L317)
Why 115200 bps? This is already used in other places, e.g. https://github.com/NixOS/nixpkgs/pull/58196
I tested this change by building the image, booting the image, and
observing the boot process over serial:
$ cd nixos/
$ nix-build -A config.system.build.isoImage -I nixos-config=modules/installer/cd-dvd/installation-cd-minimal.nix default.nix
$ sudo cp /nix/store/arcl702c3z8xlndlvnfplq9yhixjvs9k-nixos-20.09pre-git-x86_64-linux.iso/iso/nixos-20.09pre-git-x86_64-linux.iso /dev/sdb
$ picocom -b 115200 /dev/ttyUSB0
This reverts commit aab534b894 & uses the
driverInteractive attribute for the test driver instead.
This has the same effect but removes the extra module in the
nixos-build-vms code.
When I test a change e.g. in the module system manually, I usually use
`nixos-build-vms(8)` which also gives me a QEMU window where I can play
around in the freshly built VM.
It seems as this has changed recently when the default package for
non-interactive VM tests using the same framework was switched to
`pkgs.qemu_test` to reduce the closure size. While this is a reasonable
decision for our CI tests, I think that you really want a QEMU window of
the VM by default when using `nixos-build-vms(8)`.
[1] bc2188b083
The only nix version available in the installer should be the version
configure in the module system. If someone needs `nixUnstable` in their
`nixos-install` they should probably set the module option and not just
add it to the closure.
$EDITOR is allowed to contain flags, so it is important to allow the
shell to split this normally. For example, Sublime Text needs to be
passed --wait, since otherwise it will daemonise.
$NIXOS_CONFIG can be set to a directory, in which case the file used
is $NIXOS_CONFIG/default.nix. This updates 'nixos-rebuild edit' to
handle that case correctly.
This allows to perform `dd if= of=$img` after the image is built
which is handy to add e.g. uBoot SPL to the built image.
Instructions for some ARM boards sometimes contain this step
that needs to be performed manually, with this patch it can be
part of the nix file used to built the image.
