Arch Linux

dsana123

Member

Registered: 2013-08-27

Posts: 19

Macbook Pro 12,1 (13 inch 2015) and automatically booting from SD card

Hi,

Last month I bought a Macbook Pro 12,1 (13 inch 2015) and installed Arch Linux on the SD card (GPT disk with ESP and root partition) and configured the system to boot via Apple Startup Manager by pressing the 'Alt' key on bootup.

This works well, but now I'm trying to figure out how to boot automatically into Arch Linux for greater convinenence (i.e. without needing to press the 'Alt' key on bootup).

I set Arch Linux to boot automatically by pressing the CTRL key when select Arch Linux in the Apple Startup Manager.

Upon booting the system hangs immediately after the following message:

Loading initial ramdisk

What I have done:

1) Checked the journal log. There were no messages.
2) Read up on the boot process.
3) Inspected the initial ramdisk to determine what modules are loaded.

I think that the SD card is detected since the loading initial ramdisk message is output. This suggests that at this point the ESP is accessible (the grub EFI program and kernel and initrd images are stored in the ESP).

I think the problem may be due to system initialisation that is performed when the Apple Startup Manager is invoked with the 'Alt' key, and that this system initialisation is not performed when booting automatically. I think this may be so because when invoked with the 'Alt' key the Apple Startup Manager takes five seconds to detect the SD card and to present the Arch Linux option. This delay I think may be due system initialisation of some sort, but I have no evidence to back this up.

Unfortunately, I am not knowledgable about Apple Startup Manager or the linux boot process and I failed at finding sufficient documentation on Apple Startup Manager the Internet.

Would anyone like to offer suggestions?

For completeness, here's the initramfs info:

$ lsinitcpio -a /boot/initramfs-linux.img
==> Image: /boot/initramfs-linux.img 
==> Created with mkinitcpio 19
==> Kernel: 4.4.1-2-ARCH
==> Size: 3.32 MiB
==> Compressed with: gzip
  -> Uncompressed size: 8.83 MiB (.375 ratio)
  -> Estimated extraction time: 0.102s

==> Included modules:
  ahci		  crc16		  hid		  hid-generic	  libahci	  mbcache	  sd_mod	  uas		  usbcore	  usb-storage	  xhci-pci
  cdrom		  ext4		  hid-apple	  jbd2		  libata	  scsi_mod	  sr_mod	  usb-common	  usbhid	  xhci-hcd

==> Included binaries:
  blkid			  fsck			  kmod			  switch_root		  udevadm
  busybox		  fsck.ext4		  mount			  systemd-tmpfiles

==> Early hook run order:
  udev

==> Hook run order:
  udev

==> Cleanup hook run order:
  udev

Last edited by dsana123 (2016-02-06 10:50:42)

dsana123

Member

Registered: 2013-08-27

Posts: 19

Re: Macbook Pro 12,1 (13 inch 2015) and automatically booting from SD card

OK, apparently it does boot, but takes some time, perhaps 30 seconds or more. My patience had run out and I assumed that the boot process was hung indefinitely.

dsana123

Member

Registered: 2013-08-27

Posts: 19

Re: Macbook Pro 12,1 (13 inch 2015) and automatically booting from SD card

Unfortunately I'm unable to repeat the successful (albeit long) automatic boot. Moving back to booting via the 'Alt' key for now.