Apple mini aluminium keyboard in Linux and Initrd Notes

Problem: The Fn key on my Apple mini aluminium keyboard (wired) doesn’t work in Linux.

Solution, according to long Google research: the hid-apple and usbhid modules in recent kernel versions list the combination of properties of this keyboard so the kernel can support it properly.

Problem: I don’t want to recompile my entire kernel.

Solution: In the case of usbhid, Ryan Finnie points out that the driver accepts keyboard properties configuration with an option, so I don’t need to recompile anything in the first place:

modprobe usbhid quirks=0x05ac:0x021d:0x00000800

Problem: In the case of hid-apple, no handy option like that exists.

Solution: It’s only necessary to compile a newer version of that one module. Just nab a the latest hid-apple.c and the latest hid-ids.h form the kernel gitweb, and following instructions for compiling a single kernel module from Vivek Gite, stick them in a directory along with a Makefile like so:

obj-m = hid-apple.o
KVERSION = $(shell uname -r)
all:
	make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
clean:
	make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean

Then you can just make the module, and after that:

DRV=/lib/modules/$(uname -r)/kernel/drivers
mkdir $DRV/local                          # make a place for local drivers
cp hid-apple.ko $DRV/local/               # put ours in there
mv $DRV/hid/hid-apple.{k,x}o              # disable the existing hid-apple.ko
depmod -a                                 # rebuild module database

It may be necessary to do more than this depending on your distribution. I run Slackware, which doesn’t have introduce conventions of its own, so that was all I needed to do.

Problem: I’m running a mostly monolithic kernel, with which modprobe fails for both usbhid and hid-apple. I need to boot a modular kernel. To do so I have to build an initrd with the right modules to boot. The only modules necessary are the ones needed to access the root filesystem; after that, the others can be loaded from there. I know I need a non-bog-standard SATA driver, and the ext3 module. But which driver(s)?

Solution: lspci -vv reveals which drivers are used for which PCI devices.

Problem: I have ata_piix in there, which does not correspond to any module, only to a ata_piix.c in the kernel source tree; as well as PIIX_IDE, which doesn’t even correspond to any file.

Solution: Grepping the kernel source for PIIX_IDE reveals it’s in piix.c. Along with ata_piix.c, the two of them go into the directory alongside hid-apple.c, and the first line in the Makefile becomes

obj-m = piix.o ata_piix.o hid-apple.o

Same procedure as above follows to compile and install the lot.

Nearly done. Remaining steps:

Rebuild the initrd: cd /boot && mkinitrd -c -k $(uname -r) -m ata_piix:piix:ext3. Don’t forget to run lilo to fix up the boot loader.
Set up the right options to be passed automatically to the usbhid and hid-apple modules when they’re loaded at boot: make /etc/modprobe.d/apple-mini-alu-kb.conf with the following contents:
```
  options usbhid quirks=0x05ac:0x021d:0x00000800
  options hid-apple fnmode=2
```
And for good measure, this is what I put in ~/.xinitrc to map the keyboard the way I want it:
```
  setxkbmap -option '' -model apple us '' ctrl:nocaps altwin:meta_win altwin:swap_lalt_lwin
```
That will turn the Caps Lock into an extra Ctrl key, will make the Cmd keys work as Meta keys, and will swap the left Alt and Cmd/Meta keys. For some odd reason, it does not remove the Mod4 modifier that belongs on the Cmd/Meta key from the Alt key, though, so it's necessary to follow this up with:
```
  xmodmap -e 'remove Mod4 = Alt_L'
```

Phew.

FIXME: remaining niggles:

hid-apple apparently doesn’t get loaded at boot with the modular kernel

ap/Apple_KB_and_Initrd_Notes.mkd

Apple mini aluminium keyboard in Linux and Initrd Notes