1

After going into developer mode on my Chromebook, I noticed something odd:

chronos@localhost / $ ls /
bin  debugd  dev  etc  home  lib  lib64  lost+found  media  mnt  opt  postinst  proc  root  run  sbin  sys  tmp  usr  var

There wasn't any /boot directory. It appears that all computers(not just linux) need the /boot directory, so where is it?

Edit contents of /proc/cmdline:

cros_secure console= loglevel=7 init=/sbin/init cros_secure oops=panic panic=-1 root=/dev/dm-0 rootwait ro dm_verity.error_behavior=3 dm_verity.max_bios=-1 dm_verity.dev_wait=1 dm="1 vroot none ro 1,0 2506752 verity payload=PARTUUID=9c4a8b66-bf2d-8344-b395-cc24c0f465ca/PARTNROFF=1 hashtree=PARTUUID=9c4a8b66-bf2d-8344-b395-cc24c0f465ca/PARTNROFF=1 hashstart=2506752 alg=sha1 root_hexdigest=f87508f343f6f7337752889bd7396a0593e694ed salt=52dd62128026d20e8cef890d18bfba577ebe23347e2ae6a12816d1e910cae197" noinitrd vt.global_cursor_default=0 kern_guid=9c4a8b66-bf2d-8344-b395-cc24c0f46
7
  • 5
    All operating systems need a way to boot, however /boot is not a universal solution to that. You might want to read this, chromium.org/chromium-os/chromiumos-design-docs/disk-format - which describes the disk format including the boot approach. Feb 22, 2016 at 12:04
  • 1
    What's the output of cat /proc/cmdline ?
    – SHW
    Feb 22, 2016 at 12:09
  • May be on other partition?
    – Pandya
    Feb 22, 2016 at 12:14
  • 1
    It may not be mounted anymore. You do need to boot from somewhere, but after that, the boot process remounts the root filesystem and others anyway, and it may not mount the boot partition as it's no longer needed (and it's safer, OS's meant for widespread public wher majority of users have no clue what they are doing, tend to hide everything, lately even the file system itself, operating only on abstract collections of files with no known location).
    – orion
    Feb 22, 2016 at 12:41
  • 1
    @ElliotA.much better to edit your original question and paste that output into it, rather than as comments. Helps when people search for similar issues. Feb 22, 2016 at 14:20

2 Answers 2

2

It appears that all computers(not just linux) need the /boot directory, so where is it?

No that's not true. Androids have a partition where the kernel is stored, a recovery partition (a fallback kernel?), a root partition and then some. Some projects use the recovery option to implement dual boot functionality, the Chrome OS developers extended this scheme and added a kernel partition A, a root partition A, kernel partition B, a root partition B and reserved space for kernel partition C, a root partition C as documented in disk-format.

There is no need for a boot directory which holds later stages of the bootloader and several older kernels because the developers wanted to get rid of as many components from the traditional boot process as they could to simplify and speed up booting.

My router running LEDE/OpenWrt doesn't have a /boot directory either.

1

There's no /boot. ChromeOS uses U-boot (not grub) and has at least 3 kernels and "boot" partitions at a time: The disk format document has a lot more detail.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.